Cancer Treatment Results  Survival Rates Cancer Treatments / Therapy Results
Cancer
 
Glossary

ABCD rating      A staging system for prostate cancer that uses ABCD. “A” and “B” refer to cancer that is confined to the prostate. “C” refers to cancer that has grown out of the prostate but has not spread to lymph nodes or other places in the body. “D” refers to cancer that has spread to lymph nodes or to other places in the body. Also called the Jewett staging system or the Whitmore-Jewett staging system.

ablation      In medicine, the removal or destruction of a body part or tissue or its function. Ablation may be performed by surgery, hormones, drugs, radiofrequency, heat, or other methods.

abscess      An enclosed collection of pus in tissues, organs, or confined spaces in the body. An abscess is a sign of infection and is usually swollen and inflamed.

action study      In cancer prevention clinical trials, a study that focuses on finding out whether actions people take can prevent cancer.

acute      Symptoms or signs that begin and worsen quickly; not chronic. 

acute lymphoblastic leukemia  (lim-fo-BLAST-ik loo-KEE-mee-a)    ALL. A quickly progressing disease in which too many immature white blood cells (called lymphoblasts) are found in the blood and bone marrow. Also called acute lymphocytic leukemia.

acute lymphocytic leukemia  (lim-fo-SIT-ik loo-KEE-mee-a)    ALL. A quickly progressing disease in which too many immature white blood cells (called lymphoblasts) are found in the blood and bone marrow. Also called acute lymphoblastic leukemia.

acute myelogenous leukemia  (mye-eh-LAH-jen-us loo-KEE-mee-a)    AML. A quickly progressing disease in which too many immature white blood cells (not lymphocytes) are found in the blood and bone marrow. Also called acute myeloid leukemia or acute nonlymphocytic leukemia.

acute myeloid leukemia  (MY-eh-loyd loo-KEE-mee-a)    AML. A quickly progressing disease in which too many immature white blood cells (not lymphocytes) are found in the blood and bone marrow. Also called acute myelogenous leukemia or acute nonlymphocytic leukemia.

acute nonlymphocytic leukemia      A quickly progressing disease in which too many immature blood-forming cells are found in the blood and bone marrow. Also called acute myeloid leukemia or acute myelogenous leukemia.

adenocarcinoma  (AD-in-o-kar-sin-O-ma)    Cancer that begins in cells that line certain internal organs and that have glandular (secretory) properties. 

adjunct agent      In cancer therapy, a drug or substance used in addition to the primary therapy.

adjunctive therapy      Another treatment used together with the primary treatment. Its purpose is to assist the primary treatment.

adjuvant therapy  (AD-joo-vant)    Treatment given after the primary treatment to increase the chances of a cure. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, or biological therapy.

adverse effect      An unwanted side effect of treatment.

agent study      In cancer prevention clinical trials, a study that tests whether taking certain medicines, vitamins, minerals, or food supplements can prevent cancer. Also a called chemoprevention study.

aggressive      A quickly growing cancer.

agranulocyte  (A-gran-yoo-lo-SITE)    A type of white blood cell; monocytes and lymphocytes are agranulocytes.

AJCC staging system      A system developed by the American Joint Committee on Cancer for describing the extent of cancer in a patient’s body. The descriptions include TNM: T describes the size of the tumor and if it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).

alkaloid      A member of a large group of chemicals that are made by plants and have nitrogen in them.

alkylating agent      A drug that is used in the treatment of cancer. It interferes with the cell's DNA and inhibits cell growth.

ALL      Acute lymphoblastic leukemia. A quickly progressing disease in which too many immature white blood cells called lymphoblasts are found in the blood and bone marrow. Also called acute lymphocytic leukemia.

all-trans retinoic acid      A form of vitamin A that is used in the treatment of acne. It is also being studied in cancer prevention and as a treatment for acute promyelocytic leukemia, usually in combination with other drugs. Also called tretinoin. 

allogeneic  (Al-o-jen-AY-ik)    Taken from different individuals of the same species. Also called allogenic.

allogeneic bone marrow transplantation  (AL-o-jen-AY-ik)    A procedure in which a person receives stem cells (cells from which all blood cells develop) from a genetically similar, but not identical, donor.

allogeneic stem cell transplantation  (AL-o-jen-AY-ik)    A procedure in which a person receives stem cells (cells from which all blood cells develop) from a genetically similar, but not identical, donor. 

allogenic      Taken from different individuals of the same species. Also called allogeneic.

alpha-fetoprotein  (AL-fa-FEE-toe-PRO-teen)    AFP. A protein normally produced by a fetus. AFP levels are usually undetectable in the blood of healthy adult men or women (who are not pregnant). An elevated level of AFP suggests the presence of either a primary liver cancer or germ cell tumor.

AML      Acute myelogenous leukemia. A quickly progressing disease in which too many immature blood-forming cells are found in the blood and bone marrow. Also called acute myeloid leukemia or acute nonlymphocytic leukemia.

analgesic      A drug that reduces pain. Analgesics include aspirin, acetaminophen, and ibuprofen.

analog      In chemistry, a substance that is similar, but not identical, to another. 

anaphylactic shock      A severe and sometimes life-threatening immune system reaction to an antigen that a person has been previously exposed to. The reaction may include itchy skin, edema, collapsed blood vessels, fainting, and difficulty in breathing.

anaplastic  (an-ah-PLAS-tik)    A term used to describe cancer cells that divide rapidly and have little or no resemblance to normal cells.

androgen  (AN-dro-jen)    A type of hormone that promotes the development and maintenance of male sex characteristics.

androgen ablation      Treatment to suppress or block the production of male hormones. Androgen suppression is achieved by surgical removal of the testicles, by taking female sex hormones, or by taking other drugs (antiandrogens). Also called androgen suppression.

androgen suppression      Treatment to suppress or block the production of male hormones. Androgen suppression is achieved by surgical removal of the testicles, by taking female sex hormones, or by taking other drugs, antiandrogens. Also called androgen ablation.

androgen-independent      Describes the ability of tumor cells to grow in the absence of androgens (hormones that promote the development and maintenance of male sex characteristics). Many early prostate cancers require androgens for growth, but advanced prostate cancers are often androgen-independent.

anemia  (a-NEE-mee-a)    A condition in which the number of red blood cells is below normal.

anesthesia  (an-es-THEE-zha)    Drugs or substances that cause loss of feeling or awareness. Local anesthetics cause loss of feeling in a part of the body. General anesthetics put the person to sleep.

anesthesiologist      A doctor who specializes in giving drugs or other agents to prevent or relieve pain during surgery or other procedures being done in the hospital.

anesthetic  (an-es-THET-ik)    A substance that causes loss of feeling or awareness. Local anesthetics cause loss of feeling in a part of the body. General anesthetics put the person to sleep.

angiogenesis  (an-gee-o-GEN-eh-sis)    Blood vessel formation. Tumor angiogenesis is the growth of blood vessels from surrounding tissue to a solid tumor. This is caused by the release of chemicals by the tumor.

angiogenesis inhibitor      A substance that may prevent the formation of blood vessels. In anticancer therapy, an angiogenesis inhibitor prevents the growth of blood vessels from surrounding tissue to a solid tumor.

angiostatin      A protein normally made by the body. It can also be made in the laboratory, and is being studied in the treatment of cancer. Angiostatin may prevent the growth of new blood vessels from the surrounding tissue to a solid tumor. It belongs to the family of drugs called angiogenesis inhibitors.

antiangiogenesis      Prevention of the growth of new blood vessels.

antibiotic  (an-tih-by-AH-tik)    A drug used to treat infections caused by bacteria and other microorganisms.

antibody  (AN-tih-BOD-ee)    A type of protein made by certain white blood cells in response to a foreign substance (antigen). Each antibody can bind to only a specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

antibody therapy      Treatment with an antibody, a substance that can directly kill specific tumor cells or stimulate the immune system to kill tumor cells.

antiestrogen      A substance that blocks the activity of estrogens, the family of hormones that promote the development and maintenance of female sex characteristics.

antifolate      A substance that blocks the activity of folic acid. Antifolates are used to treat cancer. Also called folate antagonist.

antifungal      A drug that treats infections caused by fungi.

antigen      A substance that causes the immune system to make a specific immune response.

antigen-presenting cell      APC. A cell that shows antigen on its surface to other cells of the immune system. This is an important part of an immune response.

antigen-presenting cell vaccine      A vaccine made of antigens and antigen-presenting cells (APCs). Also called APC vaccine.

antihormone therapy      Treatment with drugs, surgery, or radiation in order to block the production or action of a hormone. Antihormone therapy may be used in cancer treatment because certain hormones are able to stimulate the growth of some types of tumors. 

antimetabolite      A drug that is very similar to natural chemicals in a normal biochemical reaction in cells but different enough to interfere with the normal division and functions of cells.

antimicrotubule agent      A drug that inhibits cell growth by stopping cell division. Antimicrotubule agents are used as treatments for cancer. Also called antimitotic agents, mitotic inhibitors, and taxanes. Docetaxel and paclitaxel are antimicrotubule agents.

antimitotic agent      A drug that inhibits cell growth by stopping cell division. Antimitotic agents are used as treatments for cancer. Also called antimicrotubule agents, mitotic inhibitors, and taxanes. Docetaxel and paclitaxel are antimitotic agents.

antineoplaston      A substance isolated from normal human blood and urine that is being tested as a type of treatment for some tumors and AIDS.

antiparasitic      A drug used to treat infections caused by bacteria and parasites. It is also used in the treatment of some cancers.

apheresis      A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor. Also called pheresis.

apnea     cessation of breathing

apoptosis  (ap-o-TOE-sis)    A normal series of events in a cell that leads to its death.

arctigenin      A substance found in certain plants, including burdock. It has shown antiviral and anticancer effects. Arctigenin belongs to a group of substances called lignans.

arctiin      A substance found in certain plants, including burdock. It has shown anticancer effects. Arctiin belongs to a group of substances called lignans.

arginine butyrate      A substance that is being studied in the treatment of cancer.

aromatase inhibitor  (a-ROW-ma-tays in-HIB-it-er)    A drug that prevents the formation of estradiol, a female hormone, by interfering with an aromatase enzyme. Aromatase inhibitors are used as a type of hormone therapy for postmenopausal women who have hormone-dependent breast cancer.

arsenic      A poisonous chemical used to kill weeds and pests. Also used in cancer therapy.

arsenic trioxide      A substance that induces programmed cell death (apoptosis) in certain cancer cells. It belongs to the family of drugs called antineoplastics.

arterial embolization  (ar-TEE-ree-al EM-bo-lih-ZAY-shun)    The blocking of an artery by a clot of foreign material. This can be done as treatment to block the flow of blood to a tumor.

arthralgia    Pain in a joint.

asthenia   Loss or lack of bodily strength; weakness; debility.

astrocytoma  (as-troe-sye-TOE-ma)    A tumor that begins in the brain or spinal cord in small, star-shaped cells called astrocytes.

ataxia      Loss of muscle coordination.

ataxic gait  (ah-TAK-sik)    Awkward, uncoordinated walking.

athymic, nude mouse      A type of laboratory mouse that is hairless, lacks a normal thymus gland, and has a defective immune system because of a genetic mutation. Athymic, nude mice are often used in cancer research because they do not reject tumor cells, from mice or other species.

atypical teratoid/rhabdoid tumor      ATT/RHT or AT/RT. An aggressive cancer of the central nervous system, kidney, or liver that occurs in very young children.

autologous  (aw-TAHL-o-gus)    Taken from an individual's own tissues, cells, or DNA.

autologous bone marrow transplantation  (aw-TAHL-o-gus)    A procedure in which bone marrow is removed from a person, stored, and then given back to the person after intensive treatment.

autologous stem cell transplantation  (aw-TAHL-o-gus)    A procedure in which stem cells (cells from which all blood cells develop) are removed, stored, and then given back to the same person.

B cell      A white blood cell that makes antibodies and is an important part of the immune system. B cells come from bone marrow. Also called B lymphocyte.

B lymphocyte      A white blood cell that makes antibodies and is an important part of the immune system. B lymphocytes come from bone marrow. Also called B cell.

Bacillus Calmette Guérin  (bah-SILL-us KAL-met GAY-ran)    BCG. A type of bacteria used in cancer treatment to stimulate the immune system. It is also used to vaccinate against tuberculosis.

bacteremia    The presence of bacteria in the blood.

bacterial toxin      A toxic substance, made by bacteria, that can be modified to kill specific tumor cells without harming normal cells.

barium enema      A procedure in which a liquid with barium in it is put into the rectum and colon by way of the anus. Barium is a silver-white metallic compound that helps to show the image of the lower gastrointestinal tract on an x-ray.

barium solution      A liquid containing barium sulfate that is used in x-rays to highlight parts of the digestive system.

basal cell carcinoma  (BAY-sal sel kar-sin-O-ma)    A type of skin cancer that arises from the basal cells, small round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.

benign  (beh-NINE)    Not cancerous. Benign tumors do not spread to tissues around them or to other parts of the body.

benign proliferative breast disease      A group of noncancerous conditions that may increase the risk of developing breast cancer. Examples include ductal hyperplasia, lobular hyperplasia, and papillomas.

benign prostatic hyperplasia  (hye-per-PLAY-zha)    BPH. A benign (noncancerous) condition in which an overgrowth of prostate tissue pushes against the urethra and the bladder, blocking the flow of urine. Also called benign prostatic hypertrophy.

benign prostatic hypertrophy      BPH. A benign (noncancerous) condition in which an overgrowth of prostate tissue pushes against the urethra and the bladder, blocking the flow of urine. Also called benign prostatic hyperplasia.

benign tumor  (beh-NINE)    A noncancerous growth that does not invade nearby tissue or spread to other parts of the body.

beta carotene      A vitamin A precursor. Beta carotene belongs to the family of fat-soluble vitamins called carotenoids.

beta-glucan      A type of polysaccharide (string of sugar molecules) obtained from several types of mushrooms. It is being studied as a treatment for cancer and as an immune system stimulant.

beta-human chorionic gonadotropin      ß-hCG. A hormone normally found in the blood and urine during pregnancy. It may also be produced by some tumor cells. An increased level of ß-hCG may be a sign of cancer of the testis, uterus, ovary, liver, stomach, pancreas, or lung. ß-hCG may also be produced in response to certain conditions that are not cancer. ß-hCG is being studied in the treatment of Kaposi’s sarcoma.

bias      In a clinical trial, a flaw in the study design or method of collecting or interpreting information. Biases can lead to incorrect conclusions about what the study or trial showed.

biological response modifier  (by-o-LAHJ-i-kul...)    BRM. Treatment to stimulate or restore the ability of the immune system to fight infections and other diseases. Also used to lessen side effects that may be caused by some cancer treatments. Also known as biological therapy, immunotherapy, or biotherapy.

biological therapy  (by-o-LAHJ-i-kul)    Treatment to stimulate or restore the ability of the immune system to fight infections and other diseases. Also used to lessen side effects that may be caused by some cancer treatments. Also known as immunotherapy, biotherapy, or biological response modifier (BRM) therapy.

biomarker      A substance sometimes found in the blood, other body fluids, or tissues. A high level of biomarker may mean that a certain type of cancer is in the body. Examples of biomarkers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (prostate cancer). Also called tumor marker.

biopsy  (BY-op-see)    The removal of cells or tissues for examination under a microscope. When only a sample of tissue is removed, the procedure is called an incisional biopsy or core biopsy. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy or fine-needle aspiration. 

biopsy specimen      Tissue removed from the body and examined under a microscope to determine whether disease is present.

biotherapy      Treatment to stimulate or restore the ability of the immune system to fight infections and other diseases. Also used to lessen side effects that may be caused by some cancer treatments. Also known as biological therapy, immunotherapy, or biological response modifier (BRM) therapy.

blast      An immature blood cell.

blessed thistle      Cnicus benedictus. A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Blessed thistle may have anti-inflammatory and anticancer effects. Also called St. Benedict's thistle, cardin, holy thistle, and spotted thistle.

blinded study      A type of study in which the patients (single-blinded) or the patients and their doctors (double-blinded) do not know which drug or treatment is being given. The opposite of a blinded study is an open label study.

blood cell count      A test to check the number of red blood cells, white blood cells, and platelets in a sample of blood. Also called complete blood count (CBC).

blood-brain barrier      A network of blood vessels with closely spaced cells that makes it difficult for potentially toxic substances (such as anticancer drugs) to penetrate the blood vessel walls and enter the brain.

blood-brain barrier disruption      BBBD. The use of drugs to create openings between cells in the blood-brain barrier. The blood-brain barrier is a protective network of blood vessels and tissue that protects the brain from harmful substances, but can also prevent anticancer drugs from reaching the brain. Once the barrier is opened, anticancer drugs may be infused into an artery that goes to the brain, in order to treat brain tumors. 

bolus      A single dose of drug usually injected into a blood vessel over a short period of time. Also called bolus infusion.

bone marrow      The soft, sponge-like tissue in the center of most large bones. It produces white blood cells, red blood cells, and platelets.

bone marrow ablation      The destruction of bone marrow using radiation or drugs.

bone marrow aspiration  (as-per-AY-shun)    The removal of a small sample of bone marrow (usually from the hip) through a needle for examination under a microscope.

bone marrow biopsy  (BY-op-see)    The removal of a sample of tissue from the bone marrow with a needle for examination under a microscope.

bone marrow metastases      Cancer that has spread from the original (primary) tumor to the bone marrow.

bone marrow transplantation  (trans-plan-TAY-shun)    A procedure to replace bone marrow that has been destroyed by treatment with high doses of anticancer drugs or radiation. Transplantation may be autologous (an individual's own marrow saved before treatment), allogeneic (marrow donated by someone else), or syngeneic (marrow donated by an identical twin).

bone metastases      Cancer that has spread from the original (primary) tumor to the bone.

bone scan      A technique to create images of bones on a computer screen or on film. A small amount of radioactive material is injected into a blood vessel and travels through the bloodstream; it collects in the bones and is detected by a scanner.

brachytherapy  (BRAKE-ih-THER-a-pee)    A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called internal radiation, implant radiation, or interstitial radiation therapy. 

bradycardia    Slowness of the heartbeat.

brain metastasis      Cancer that has spread from the original (primary) tumor to the brain.

brain stem      The part of the brain that is connected to the spinal cord.

brain stem glioma  (glee-O-ma)    A tumor located in the part of the brain that connects to the spinal cord (the brain stem). It may grow rapidly or slowly, depending on the grade of the tumor.

brain stem tumor      A tumor in the part of the brain that connects to the spinal cord (the brain stem).

breast cancer in situ      Abnormal cells that are confined to the ducts or lobules in the breast. There are two forms, called ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS).

breast duct endoscopy      A method used to examine the lining of the breast ducts to look for abnormal tissue. A very thin, flexible, lighted tube attached to a camera is inserted through the nipple, and threaded into the breast ducts deep in the breast. Tissue and fluid samples may be removed during the procedure. 

bronchoscope  (BRON-ko-skope)    A thin, lighted tube used to examine the inside of the trachea and bronchi, the air passages that lead to the lungs.

bronchoscopy  (bron-KOS-ko-pee)    A procedure in which a thin, lighted tube is inserted through the nose or mouth. This allows examination of the inside of the trachea and bronchi (air passages that lead to the lung), as well as the lung. Bronchoscopy may be used to detect cancer or to perform some treatment procedures.

bryostatin      A substance that is being studied in the treatment of cancer. It is obtained from a marine organism.

burdock      Arctium lappa. A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called lappa and happy major.

Burkitt's lymphoma      An aggressive (rapidly progressing) type of B-cell non-Hodgkin's lymphoma that occurs most often in children and young adults. The disease may affect the jaw, central nervous system, bowel, kidneys, ovaries, or other organs. There are three main types of Burkitt’s lymphoma (sporadic, endemic, and immunodeficiency related). Sporadic Burkitt’s lymphoma occurs throughout the world, and endemic Burkitt’s lymphoma occurs in Africa. Immunodeficiency-related Burkitt’s lymphoma is most often seen in AIDS patients.

c-erbB-2      The gene that controls cell growth by making the human epidermal growth factor receptor 2. Also called HER2/neu.

CA 19-9 assay      A test that measures the level of CA 19-9 in the blood. CA 19-9 is a tumor marker released into the bloodstream from both cancer cells and normal cells. Higher than normal amounts of CA 19-9 in the blood can be a sign of gallbladder or pancreatic cancer or other conditions.

cachexia  (ka-KEK-see-a)    Loss of body weight and muscle mass, and weakness that may occur in patients with cancer, AIDS, or other chronic diseases.

cancer      A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread through the bloodstream and lymphatic system to other parts of the body. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the bloodstream. Lymphoma is cancer that begins in the cells of the immune system.

carcinogenesis      The process by which normal cells are transformed into cancer cells.

carcinoma  (KAR-si-NO-ma)    Cancer that begins in the skin or in tissues that line or cover internal organs.

carcinoma in situ  (KAR-si-NO-ma in SYE-too)    Cancer that involves only the cells in which it began and that has not spread to nearby tissues.

carcinosarcoma      A malignant tumor that is a mixture of carcinoma (cancer of epithelial tissue, which is skin and tissue that lines or covers the internal organs) and sarcoma (cancer of connective tissue, such as bone, cartilage, and fat).

carcinosis      A condition in which cancer is spread widely throughout the body, or, in some cases, to a relatively large region of the body. Also called carcinomatosis.

cardiotoxicity      Toxicity that affects the heart.

cardiovascular      Having to do with the heart and blood vessels.

carotenoid      A substance found in yellow and orange fruits and vegetables and in dark green, leafy vegetables. Carotenoids may reduce the risk of developing cancer.

case report      A detailed report of the diagnosis, treatment, and follow-up of an individual patient. Case reports also contain some demographic information about the patient (for example, age, gender, ethnic origin).

case series      A group or series of case reports involving patients who were given similar treatment. Reports of case series usually contain detailed information about the individual patients. This includes demographic information (for example, age, gender, ethnic origin) and information on diagnosis, treatment, response to treatment, and follow-up after treatment.

case-control study      A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls). Researchers study the medical and lifestyle histories of the people in each group to learn what factors may be associated with the disease or condition. For example, one group may have been exposed to a particular substance that the other was not. Also called a retrospective study. 

CAT scan      A series of detailed pictures of areas inside the body, taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computerized axial tomography, computed tomography (CT scan), or computerized tomography.

cauterization  (KAW-ter-ih-ZAY-shun)    The destruction of tissue with a hot instrument, an electrical current, or a caustic substance.

CBC      Complete blood count. A test to check the number of red blood cells, white blood cells, and platelets in a sample of blood. Also called blood cell count.

CEA      Carcinoembryonic antigen. A substance that is sometimes found in an increased amount in the blood of people who have certain cancers, other diseases, or who smoke. It is used as a tumor marker for colorectal cancer.

CEA assay      A laboratory test to measure carcinoembryonic antigen (CEA), a substance that is sometimes found in an increased amount in the blood of people who have certain cancers.

cell differentiation      The process during which young, immature (unspecialized) cells take on individual characteristics and reach their mature (specialized) form and function.

cell proliferation      An increase in the number of cells as a result of cell growth and cell division.

cellular adoptive immunotherapy      A treatment used to help the immune system fight cancer. A cancer patient’s T cells (a type of white blood cell) are collected and grown in the laboratory to increase the number of T cells that are able to kill the person’s cancer cells. These cancer-specific T cells are given back to the patient to help the immune system fight the cancer. 

central nervous system      CNS. The brain and spinal cord.

central nervous system primitive neuroectodermal tumor      CNS PNET. A type of cancer that arises from a particular type of cell within the brain or spinal cord.

cerebellopontine  (SER-uh-BEL-o-PON-teen)    Having to do with two structures of the brain, the cerebellum (located at the lower back of the brain) and the pons (located at the base of the brain in front of the cerebellum) and the area between them.

cerebellum  (ser-uh-BEL-um)    The portion of the brain in the back of the head between the cerebrum and the brain stem. The cerebellum controls balance for walking and standing, and other complex motor functions.

cerebral hemisphere  (seh-REE-bral HEM-is-feer)    One half of the cerebrum, the part of the brain that controls muscle functions and also controls speech, thought, emotions, reading, writing, and learning. The right hemisphere controls the muscles on the left side of the body, and the left hemisphere controls the muscles on the right side of the body.

cerebrospinal fluid  (seh-REE-broe-SPY-nal)    CSF. The fluid flowing around the brain and spinal cord. Cerebrospinal fluid is produced in the ventricles in the brain.

cerebrum  (seh-REE-brum)    The largest part of the brain. It is divided into two hemispheres, or halves, called the cerebral hemispheres. Areas within the cerebrum control muscle functions and also control speech, thought, emotions, reading, writing, and learning.

cervix  (SER-viks)    The lower, narrow end of the uterus that forms a canal between the uterus and vagina.

chemoembolization      A procedure in which the blood supply to the tumor is blocked surgically or mechanically and anticancer drugs are administered directly into the tumor. This permits a higher concentration of drug to be in contact with the tumor for a longer period of time.

chemoimmunotherapy      Chemotherapy combined with immunotherapy. Chemotherapy uses different drugs to kill or slow the growth of cancer cells; immunotherapy uses treatments to stimulate or restore the ability of the immune system to fight cancer. 

chemoradiation      Treatment that combines chemotherapy with radiation therapy. Also called chemoradiotherapy. 

chemotherapy  (kee-mo-THER-a-pee)    Treatment with anticancer drugs that are cytotoxic (toxic to cells).

Chinese rhubarb      Rheum palmatum or Rheum officinale. The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Also called rhubarb, da-huang, Indian rhubarb, and Turkish rhubarb.

choroid plexus tumor      A rare type of cancer that occurs in the ventricles of the brain. It usually occurs in children younger than 2 years.

chromosome  (KRO-mo-some)    Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.

chronic  (KRAHN-ik)    A disease or condition that persists or progresses over a long period of time.

clinical study      A type of research study that uses volunteers to test new methods of screening, prevention, diagnosis, or treatment of a disease. The trial may be carried out in a clinic or other medical facility. Also called a clinical trial. 

clinical trial      A type of research study that uses volunteers to test new methods of screening, prevention, diagnosis, or treatment of a disease. The trial may be carried out in a clinic or other medical facility. Also called a clinical study.

CNS      Central nervous system. The brain and spinal cord.

CNS metastasis      Cancer that has spread from the original (primary) tumor to the central nervous system.

CNS prophylaxis  (pro-fih-LAK-sis)    Chemotherapy or radiation therapy given to the central nervous system (CNS) as a preventive treatment. It is given to kill cancer cells that may be in the brain and spinal cord, even though no cancer has been detected there. Also called CNS sanctuary therapy. 

CNS tumor      A tumor of the central nervous system, including brain stem glioma, craniopharyngioma, medulloblastoma, and meningioma.

cobalt 60      A radioactive form of the metal cobalt, which is used as a source of radiation to treat cancer.

coenzyme Q10      A substance found in most tissues in the body, and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called Q10, CoQ10, vitamin Q10, and ubiquinone.

colon  (KO-lun)    The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus. 

colon cancer  (KO-lun)    Cancer that develops in the tissues of the colon.

colonoscopy  (ko-lun-AHS-ko-pee)    An examination of the inside of the colon using a thin, lighted tube (called a colonoscope) inserted into the rectum. If abnormal areas are seen, tissue can be removed and examined under a microscope to determine whether disease is present.

colony-stimulating factor      A substance that stimulates the production of blood cells. Colony-stimulating factors include granulocyte colony-stimulating factors (also called G-CSF and filgrastim), granulocyte-macrophage colony-stimulating factors (also called GM-CSF and sargramostim), and promegapoietin.

colorectal  (ko-lo-REK-tul)    Having to do with the colon or the rectum.

combination chemotherapy      Treatment using more than one chemotherapy drug.

comorbidity      The condition of having two or more diseases at the same time.

complete blood count      CBC. A test to check the number of red blood cells, white blood cells, and platelets in a sample of blood. Also called blood cell count.

complete hysterectomy      Surgery to remove the entire uterus, including the cervix. Sometimes, not all of the cervix is removed. Also called total hysterectomy.

complete metastasectomy  (meh-TAS-ta-SEC-tuh-mee)    Surgery to remove all metastases (tumors formed from cells that have spread from the primary tumor). 

complete remission      The disappearance of all signs of cancer in response to treatment. This does not always mean the cancer has been cured. Also called a complete response.

complete response      The disappearance of all signs of cancer in response to treatment. This does not always mean the cancer has been cured. Also called a complete remission.

computed tomographic colonography      CTC. A procedure in which a detailed picture of the colon is created by an x-ray machine linked to a computer. Also called computed tomography (CT) scan or computerized axial tomography (CAT) scan of the colon.

computed tomography  (tuh-MAH-gra-fee)    CT scan. A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computerized tomography and computerized axial tomography (CAT) scan.

computerized axial tomography  (com-PYEW-ter-ized AX-ee-al tuh-MAH-gra-fee)    A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called CAT scan, computed tomography (CT scan), or computerized tomography.

computerized tomography      A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computerized axial tomography (CAT) scan and computed tomography (CT scan).

concurrent therapy      A treatment that is given at the same time as another.

consecutive case series      A clinical study that includes all eligible patients identified by the researchers during the study registration period. The patients are treated in the order in which they are identified. This type of study usually does not have a control group. 

consolidation therapy      A type of high-dose chemotherapy often given as the second phase (after induction therapy) of a cancer treatment regimen for leukemia. Also called intensification therapy. 

control group      In a clinical trial, the group that does not receive the new treatment being studied. This group is compared to the group that receives the new treatment, to see if the new treatment works.

controlled clinical trial      A clinical study that includes a comparison (control) group. The comparison group receives a placebo, another treatment, or no treatment at all.

controlled study      An experiment or clinical trial that includes a comparison (control) group.

cooperative group      A group of physicians, hospitals, or both formed to treat a large number of persons in the same way so that a new treatment can be evaluated quickly. Clinical trials of new cancer treatments often require many more people than a single physician or hospital can care for.

CoQ10      A substance found in most tissues in the body, and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, Q10, vitamin Q10, and ubiquinone.

craniotomy  (kray-nee-AH-toe-mee)    An operation in which an opening is made in the skull.

cruciferous vegetable      A member of the family of vegetables that includes kale, collard greens, broccoli, cauliflower, cabbage, Brussels sprouts, and turnips. These vegetables contain substances that may protect against cancer. 

cryopreservation      The process of cooling and storing cells, tissues, or organs at very low or freezing temperatures to save them for future use.

cryosurgery  (KRYE-o-SER-juh-ree)    Treatment performed with an instrument that freezes and destroys abnormal tissues.

cryotherapy      Any method that uses cold temperature to treat disease.

CSF      Cerebrospinal fluid. The fluid flowing around the brain and spinal cord. CSF is produced in the ventricles of the brain.

CT scan      Computed tomography scan. A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computerized tomography and computerized axial tomography (CAT) scan.

cumulative dose      In medicine, the total amount of a drug or radiation given to a patient over time; for example, the total dose of radiation given in a series of radiation treatments.

cytology      The study of cells using a microscope.

cytotoxic      Cell-killing.

cytotoxic chemotherapy      Anticancer drugs that kill cells, especially cancer cells.

cytotoxic T cell        A type of white blood cell that can directly destroy specific cells. T cells can be separated from other blood cells, grown in the laboratory, and then given to a patient to destroy tumor cells. Certain cytokines can also be given to a patient to help form cytotoxic T cells in the patient's body.

da-huang      Rheum palmatum or Rheum officinale. The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Also called rhubarb, Chinese rhubarb, Indian rhubarb, and Turkish rhubarb.

DCIS      Ductal carcinoma in situ. A noninvasive, precancerous condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. Also called intraductal carcinoma.

de novo  (dih NO-vo)    In cancer, the first occurrence of cancer in the body.

dendritic cell      A special type of antigen-presenting cell (APC) that activates T lymphocytes. 

dendritic cell vaccine      A vaccine made of antigens and dendritic antigen-presenting cells (APCs).

differentiation      In cancer, refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and tend to grow and spread at a slower rate than undifferentiated or poorly differentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.

disease progression      Cancer that continues to grow or spread.

disease-free survival      Length of time after treatment during which no cancer is found. Can be reported for an individual patient or for a study population. 

disease-specific survival      The percentage of subjects in a study who have survived a particular disease for a defined period of time. Usually reported as time since diagnosis or treatment. In calculating this percentage, only deaths from the disease being studied are counted. Subjects who died from some other cause are not included in the calculation.

disseminate  (dih-SEM-ih-NATE)    Scatter or distribute over a large area or range.

DNA      Deoxyribonucleic acid. The molecules inside cells that carry genetic information and pass it from one generation to the next.

dose-limiting      Describes side effects of a drug or other treatment that are serious enough to prevent an increase in dose or level of that treatment.

dosimetrist  do-SIM-uh-trist    A person who determines the proper radiation dose for treatment.

double-blinded      A clinical trial in which neither the medical staff nor the person knows which of several possible therapies the person is receiving.

double-contrast barium enema      A procedure in which x-rays of the colon and rectum are taken after a liquid containing barium is put into the rectum. Barium is a silver-white metallic compound that outlines the colon and rectum on an x-ray and helps show abnormalities. Air is put into the rectum and colon to further enhance the x-ray.

ductal carcinoma in situ  (DUK-tal KAR-si-NO-ma in SYE-too)    DCIS. A noninvasive, precancerous condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, ductal carcinoma in situ may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. Also called intraductal carcinoma.

Dukes' classification      A staging system used to describe the extent of colorectal cancer. Stages range from A (early stage) to D (advanced stage).

dysplasia  (dis-PLAY-zha)    Cells that look abnormal under a microscope but are not cancer.

dyspnea     Difficult or labored breathing.

EBV      Epstein-Barr virus. A common virus that remains dormant in most people. It has been associated with certain cancers, including Burkitt's lymphoma, immunoblastic lymphoma, and nasopharyngeal carcinoma.

edema  (eh-DEE-ma)    Swelling caused by excess fluid in body tissues.

efficacy      Effectiveness. In medicine, the ability of an intervention (for example, a drug or surgery) to produce the desired beneficial effect.

eligibility criteria      In clinical trials, requirements that must be met for an individual to be included in a study. These requirements help make sure that patients in a trial are similar to each other in terms of specific factors such as age, type and stage of cancer, general health, and previous treatment. When all participants meet the same eligibility criteria, it gives researchers greater confidence that results of the study are caused by the intervention being tested and not by other factors.

embolization  (EM-bo-lih-ZAY-shun)    The blocking of an artery by a clot or foreign material. Embolization can be done as treatment to block the flow of blood to a tumor.

embryonal tumor      A mass of rapidly growing cells that begins in embryonic (fetal) tissue. Embryonal tumors may be benign or malignant, and include neuroblastomas and Wilms’ tumors. Also called embryoma. 

emesis      Vomiting.

endocrine therapy      Treatment that adds, blocks or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes hormones. Also called hormone therapy, hormonal therapy, or hormone treatment.

endoscopy  (en-DAHS-ko-pee)    The use of a thin, lighted tube (called an endoscope) to examine the inside of the body.

endpoint      In clinical trials, an event or outcome that can be measured objectively to determine whether the intervention being studied is beneficial. The endpoints of a clinical trial are usually included in the study objectives. Some examples of endpoints are survival, improvements in quality of life, relief of symptoms, and disappearance of the tumor.

enteritis    Inflammation of the intestines, applied chiefly to inflammation of the small intestines.

ependymoma  (ep-en-dih-MOE-mah)    A type of brain tumor that may arise in the ventricles of the brain or in the spinal cord. Also called an ependymal tumor.

epistaxis    Nosebleed.

Epstein-Barr virus      EBV. A common virus that remains dormant in most people. It has been associated with certain cancers, including Burkitt's lymphoma, immunoblastic lymphoma, and nasopharyngeal carcinoma.

ER      Estrogen receptor. Protein found on some cancer cells to which estrogen will attach.

ER+      Estrogen receptor positive. Breast cancer cells that have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER+ need the hormone estrogen to grow and will usually respond to hormone (antiestrogen) therapy that blocks these receptor sites.

ER-      Estrogen receptor negative. Breast cancer cells that do not have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER- do not need the hormone estrogen to grow and usually do not respond to hormone (antiestrogen) therapy that blocks these receptor sites.

ErbB1      Epidermal growth factor receptor. The protein found on the surface of some cells and to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, so these cells may divide excessively in the presence of epidermal growth factor. Also known as EGFR or HER1.

erythema      Redness of the skin.

erythrocyte  (eh-RITH-ro-site)    A cell that carries oxygen to all parts of the body. Also called a red blood cell (RBC).

erythrocyte sedimentation rate      ESR. The distance red blood cells travel in one hour in a sample of blood as they settle to the bottom of a test tube. The sedimentation rate is increased in inflammation, infection, cancer, rheumatic diseases, and diseases of the blood and bone marrow. Also called sedimentation rate. 

esophagitis    Inflammation of the esophagus.

estrogen receptor      ER. Protein found on some cancer cells to which estrogen will attach.

estrogen receptor negative      ER-. Breast cancer cells that do not have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER- do not need the hormone estrogen to grow and usually do not respond to hormone (antiestrogen) therapy that blocks these receptor sites.

estrogen receptor positive      ER+. Breast cancer cells that have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER+ need the hormone estrogen to grow and will usually respond to hormone (antiestrogen) therapy that blocks these receptor sites.

estrogen receptor test      A lab test to determine if breast cancer cells have estrogen receptors. If the cells have estrogen receptors, they may depend on estrogen for growth. This information may influence how the breast cancer is treated.

estrogen replacement therapy      ERT. Hormones (estrogen, progesterone, or both) given to postmenopausal women or to women who have had their ovaries surgically removed. Hormones are given to replace the estrogen no longer produced by the ovaries.

etiology      The cause or origin of disease.

evaluable disease      Disease that cannot be measured directly by the size of the tumor but can be evaluated by other methods specific to a particular clinical trial.

evaluable patients      Patients whose response to a treatment can be measured because enough information has been collected.

Ewing's sarcoma  (YOO-ingz sar-KO-ma)    A type of bone cancer that usually forms in the middle (shaft) of large bones. Also called Ewing's sarcoma/primitive neuroectodermal tumor (PNET).

extensive-stage small cell lung cancer      Cancer has spread outside of the lung in which it began or to other parts of the body. 

external radiation  (ray-dee-AY-shun)    Radiation therapy that uses a machine to aim high-energy rays at the cancer. Also called external-beam radiation.

external-beam radiation  (ray-dee-AY-shun)    Radiation therapy that uses a machine to aim high-energy rays at the cancer. Also called external radiation.

extravasation    A discharge or escape, as of blood, from a vessel into the tissues.

false-negative test result      A test result that indicates that a person does not have a specific disease or condition when the person actually does have the disease or condition.

false-positive test result      A test result that indicates that a person has a specific disease or condition when the person actually does not have the disease or condition.

fecal occult blood test  (FEE-kul o-KULT)    FOBT. A test to check for blood in stool. (Fecal refers to stool; occult means hidden.)

fibroblast      A connective tissue cell that makes and secretes collagen proteins.

fibroid  (FYE-broyd)    A benign smooth-muscle tumor, usually in the uterus or gastrointestinal tract. Also called leiomyoma.

filgrastim      A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called granulocyte colony-stimulating factor (G-CSF).

first-line therapy      The first type of therapy given for a condition or disease. 

flow cytometry      A method of measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light. 

follicular mixed cell lymphoma  (fo-LIK-yu-ler mixed cell lim-FO-ma)    An indolent (slow-growing) type of B-cell non-Hodgkin's lymphoma (cancer of the lymphatic system) in which there are both small and large cancer cells.

fractionation      Dividing the total dose of radiation therapy into several smaller, equal doses delivered over a period of several days.

G-CSF      Granulocyte colony-stimulating factor. A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called filgrastim.

gamma irradiation      A type of radiation therapy that uses gamma radiation. Gamma radiation is a type of high-energy radiation that is different from x-rays.

gamma knife      Radiation therapy in which high-energy rays are aimed at a tumor from many angles in a single treatment session.

gastrointestinal tract  (GAS-tro-in-TES-tih-nul)    The stomach and intestines.

gene      The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

gene therapy      Treatment that alters a gene. In studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to fight the disease or to make the cancer cells more sensitive to other kinds of therapy.

gene transfer      The insertion of genetic material into a cell.

genetic markers      Alterations in DNA that may indicate an increased risk of developing a specific disease or disorder.

germ cell tumor      A type of tumor that begins in the cells that give rise to sperm or eggs. Germ cell tumors can occur almost anywhere in the body and can be either benign or malignant.

Gleason score  (GLEE-sun)    A system of grading prostate cancer cells based on how they look under a microscope. Gleason scores range from 2 to 10 and indicate how likely it is that a tumor will spread. A low Gleason score means the cancer cells are similar to normal prostate cells and are less likely to spread; a high Gleason score means the cancer cells are very different from normal and are more likely to spread.

glial cell  (GLEE-al)    A type of cell that surrounds nerve cells and holds them in place. Glial cells also insulate nerve cells from each other.

glial tumor      A general term for tumors of the central nervous system, including astrocytomas, ependymal tumors, glioblastoma multiforme, and primitive neuroectodermal tumors.

glioblastoma  (glee-o-blas-TOE-ma)    A general term that refers to malignant astrocytoma, a type of brain tumor.

glioblastoma multiforme  (glee-o-blas-TOE-ma mul-tih-FOR-may)    A type of brain tumor that forms from glial (supportive) tissue of the brain. It grows very quickly and has cells that look very different from normal cells. Also called grade IV astrocytoma.

glioma  (glee-O-ma)    A cancer of the brain that begins in glial cells (cells that surround and support nerve cells).

gliosarcoma      A type of glioma (cancer of the brain that comes from glial, or supportive, cells).

GM-CSF      Granulocyte-macrophage colony-stimulating factor. A colony-stimulating factor that stimulates the production of white blood cells, especially granulocytes and macrophages, and cells (in the bone marrow) that are precursors of platelets. It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called sargramostim.

grade      The grade of a tumor depends on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Grading systems are different for each type of cancer. 

grade IV astrocytoma      A type of brain tumor that forms from glial (supportive) tissue of the brain. It grows very quickly and has cells that look very different from normal cells. Also called glioblastoma multiforme.

grading      A system for classifying cancer cells in terms of how abnormal they appear when examined under a microscope. The objective of a grading system is to provide information about the probable growth rate of the tumor and its tendency to spread. The systems used to grade tumors vary with each type of cancer. Grading plays a role in treatment decisions.

granulocyte  (GRAN-yoo-lo-site)    A type of white blood cell that fights bacterial infection. Neutrophils, eosinophils, and basophils are granulocytes.

granulocyte colony-stimulating factor      G-CSF. A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called filgrastim. 

hairy cell leukemia      A rare type of leukemia in which abnormal B-lymphocytes (a type of white blood cell) are present in the bone marrow, spleen, and peripheral blood. When viewed under a microscope, these cells appear to be covered with tiny hair-like projections.

hand-foot syndrome      A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also known as palmar-plantar erythodysthesia.

Hedyotis diffusa      An herb used in traditional Chinese medicine to treat certain medical problems. It has been used to boost the immune system and may have anticancer effects.

Hematologic    Referring to blood and blood forming tissues.

hematologic malignancy      A cancer of the blood or bone marrow, such as leukemia or lymphoma. Also called hematologic cancer.

hematologist  (hee-ma-TOL-o-jist)    A doctor who specializes in treating blood disorders.

hematopoietic tissue      Tissue in which new blood cells are formed.

hemiperesis    Muscular weakness affecting one side of the body.

hemoglobin  (HE-muh-GLOW-bun)    The substance inside red blood cells that binds to oxygen and carries it from the lungs to the tissues.

hemorrhage      In medicine, loss of blood from damaged blood vessels. A hemorrhage may be internal or external, and usually involves a lot of bleeding in a short time. 

hepatectomy      Surgery to remove all or part of the liver.

hepatic      Refers to the liver.

hepatic arterial infusion      A procedure to deliver chemotherapy directly to the liver. Catheters are put into an artery in the groin that leads directly to the liver, and drugs are given through the catheters. 

hepatic artery      The major blood vessel that carries blood to the liver. 

hepatoblastoma  (HEP-a-toe-blas-TOE-ma)    A type of liver tumor that occurs in infants and children.

hepatocellular carcinoma  (HEP-a-toe-SEL-yoo-ler kar-sin-O-ma)    A type of adenocarcinoma, the most common type of liver tumor.

hepatocyte  (HEP-a-toe-site)    A liver cell.

hepatoma  (hep-a-TOE-ma)    A liver tumor.

HER1      Epidermal growth factor receptor. The protein found on the surface of some cells and to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, so these cells may divide excessively in the presence of epidermal growth factor. Also known as EGFR or ErbB1.

HER2/neu      Human epidermal growth factor receptor 2. The HER2/neu protein is involved in the growth of some cancer cells. Also called c-erbB-2. 

herba scutellaria barbatae      An herb used in traditional Chinese medicine to treat certain medical problems. It may have anticancer effects.

high grade      When referring to cancerous and precancerous growths, a term used to describe cells that look abnormal under a microscope. These cells are more likely to grow and spread quickly than cells in low-grade cancerous and precancerous growths.

high-dose chemotherapy      An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects including death from sepsis (infection). High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.

high-energy photon therapy      A type of radiation therapy that uses high-energy photons (units of light energy). High-energy photons penetrate deeply into tissues to reach tumors while giving less radiation to superficial tissues such as the skin. 

high-risk cancer      Cancer that is likely to recur (come back), or spread. 

histology      The study of tissues and cells under a microscope.

Hodgkin's disease      A malignant disease of the lymphatic system that is characterized by painless enlargement of lymph nodes, the spleen, or other lymphatic tissue. Other symptoms may include fever, weight loss, fatigue, or night sweats. Also called Hodgkin's lymphoma.

Hodgkin's lymphoma      A malignant disease of the lymphatic system that is characterized by painless enlargement of lymph nodes, the spleen, or other lymphatic tissue. Other symptoms may include fever, weight loss, fatigue, or night sweats. Also called Hodgkin's disease.

holy thistle      Cnicus benedictus. A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Holy thistle may have anti-inflammatory and anticancer effects. Also called blessed thistle, St. Benedict's thistle, cardin, and spotted thistle.

hormonal therapy      Treatment that adds, blocks or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes hormones. Also called hormone therapy, hormone treatment, or endocrine therapy.

hormone receptor      A protein on the surface of a cell that binds to a specific hormone. The hormone causes many changes to take place in the cell. 

hormone replacement therapy      HRT. Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called menopausal hormone therapy.

hormone responsive      In oncology, describes cancer that responds to hormone treatment.

hormone therapy      Treatment that adds, blocks or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes hormones. Also called hormonal therapy, hormone treatment, or endocrine therapy. 

hormone treatment      Treatment that adds, blocks or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes hormones. Also called hormonal therapy, hormone therapy, or endocrine therapy. 

host cell      A cell that is infected by a virus or another type of microorganism.

HRT      Hormone replacement therapy. Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called menopausal hormone therapy.

HTLV-1      Human T-cell leukemia virus type 1. A retrovirus that infects T-cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles used to inject drugs, through sexual contact, and from mother to child at birth or through breast-feeding. 

human epidermal growth factor receptor 2      HER2/neu. The HER2/neu protein is involved in growth of some cancer cells. Also called c-erbB-2. 

human T-cell leukemia virus type 1      A retrovirus that infects T-cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles used to inject drugs, through sexual contact, and from mother to child at birth or through breast-feeding. 

hydrazine sulfate      A substance that has been studied as a treatment for cancer and as a treatment for cachexia (body wasting) associated with advanced cancer.

hydrocephalus  (hye-dro-SEF-uh-lus)    The abnormal buildup of cerebrospinal fluid in the ventricles of the brain.

hyperbaric oxygen      Oxygen that is at an atmospheric pressure higher than the pressure at sea level. Breathing hyperbaric oxygen to enhance the effectiveness of radiation therapy is being studied.

hypercalcemia  (hye-per-kal-SEE-mee-a)    Abnormally high blood calcium.

hyperfractionation      A way of giving radiation therapy in smaller-than-usual doses two or three times a day instead of once a day.

hyperglycemia      Abnormally high blood sugar.

hypernephroma  (HYE-per-neh-FRO-ma)    The most common type of kidney cancer. It begins in the lining of the renal tubules in the kidney. The renal tubules filter the blood and produce urine. Also called renal cell cancer. 

hyperplasia  (hye-per-PLAY-zha)    An abnormal increase in the number of cells in an organ or tissue.

hyperthermia therapy  (hye-per-THER-mee-a)    A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs.

hyperuricemia      A buildup of uric acid (a byproduct of metabolism) in the blood; a side effect of some anticancer drugs.

hyponatremia    Deficiency of sodium in the blood.

idiopathic      Describes a disease of unknown cause.

ileostomy  (il-ee-AHS-toe-mee)    An opening into the ileum, part of the small intestine, from the outside of the body. An ileostomy provides a new path for waste material to leave the body after part of the intestine has been removed.

ileus    Obstruction of the intestines.

IM      Intramuscular. Within or into muscle.

immune response      The activity of the immune system against foreign substances (antigens).

immune system  (im-YOON)    The complex group of organs and cells that defends the body against infections and other diseases.

immunocompetent      Having the ability to produce a normal immune response.

immunocompromised      Having a weakened immune system caused by certain diseases or treatments.

immunodeficiency      The decreased ability of the body to fight infection and disease.

immunotherapy  (IM-yoo-no-THER-a-pee)    Treatment to stimulate or restore the ability of the immune system to fight infections and other diseases. Also used to lessen side effects that may be caused by some cancer treatments. Also known as biological therapy, biotherapy, or biological response modifier (BRM) therapy.

immunotoxin      An antibody linked to a toxic substance. Some immunotoxins can bind to cancer cells and kill them.

implant radiation  (ray-dee-AY-shun)    A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, internal radiation, or interstitial radiation.

implantable pump      A small device installed under the skin to administer a steady dose of drugs.

in situ cancer      Early cancer that has not spread to neighboring tissue.

incidence      The number of new cases of a disease diagnosed each year.

incisional biopsy  (in-SIH-zhun-al BY-op-see)    A surgical procedure in which a portion of a lump or suspicious area is removed for diagnosis. The tissue is then examined under a microscope.

Indian cress      Nasturtium officinale. Parts of the flowering plant have been used in some cultures to treat certain medical problems. It may have anticancer effects. Also called watercress.

Indian elm      Ulmus fulva or Ulmus rubra. The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, gray elm, red elm, and sweet elm.

Indian rhubarb      Rheum palmatum or Rheum officinale. The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Also called rhubarb, da-huang, Chinese rhubarb, and Turkish rhubarb.

Indian valerian      Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, garden valerian, Pacific valerian, Mexican valerian, garden heliotrope, and Valerianae radix. 

indolent  (IN-doe-lint)    A type of cancer that grows slowly.

induction therapy      Treatment designed to be used as a first step toward shrinking the cancer and in evaluating response to drugs and other agents. Induction therapy is followed by additional therapy to attempt to eliminate whatever cancer remains.

infiltrating cancer      Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called invasive cancer.

infiltrating ductal carcinoma      The most common type of invasive breast cancer. It starts in the cells that line the milk ducts in the breast, grows outside the ducts, and often spreads to the lymph nodes.

inflammation  (in-fla-MAY-shun)    Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.

informed consent      A process in which a person learns key facts about a clinical trial, including potential risks and benefits, before deciding whether or not to participate in a study. Informed consent continues throughout the trial.

infusion      A method of putting fluids, including drugs, into the bloodstream. Also called intravenous infusion.

inoperable      Describes a condition that cannot be treated by surgery.

Institutional Review Board      IRB. A group of scientists, doctors, clergy, and consumers at each health care facility that participates in a clinical trial. IRBs are designed to protect study participants. They review and must approve the action plan for every clinical trial. They check to see that the trial is well designed, does not involve undue risks, and includes safeguards for patients.

intensity-modulated radiation therapy      IMRT. A type of 3-dimensional radiation therapy that uses computer-generated images to show the size and shape of the tumor. Thin beams of radiation of different intensities are aimed at the tumor from many angles. This type of radiation therapy reduces the damage to healthy tissue near the tumor.

interferon  (in-ter-FEER-on)    A biological response modifier (a substance that can improve the body's natural response to infections and other diseases). Interferons interfere with the division of cancer cells and can slow tumor growth. There are several types of interferons, including interferon-alpha, -beta, and -gamma. The body normally produces these substances. They are also made in the laboratory to treat cancer and other diseases.

interleukin  (in-ter-LOO-kin)    A biological response modifier (substance that can improve the body's natural response to infection and disease) that helps the immune system fight infection and cancer. These substances are normally produced by the body. They are also made in the laboratory for use in treating cancer and other diseases.

interstitial radiation therapy      A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, internal radiation, or implant radiation.

intrahepatic  (in-tra-hep-AT-ik)    Within the liver.

intraoperative radiation therapy      IORT. Radiation treatment aimed directly at a tumor during surgery.

intraperitoneal chemotherapy  (IN-tra-per-ih-toe-NEE-al KEE-mo-THER-a-pee)    Treatment in which anticancer drugs are put directly into the abdominal cavity through a thin tube.

intrathecal  (in-tra-THEE-kal)    Describes the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord. Drugs can be injected into the fluid or a sample of the fluid can be removed for testing. 

intrathecal chemotherapy  (in-tra-THEE-kal KEE-mo-THER-a-pee)    Anticancer drugs that are injected into the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord. 

intravenous  (in-tra-VEE-nus)    IV. Within a blood vessel.

intravenous pyelogram  (in-tra-VEE-nus PYE-el-o-gram)    IVP. A series of x-rays of the kidneys, ureters, and bladder. The x-rays are taken after a dye is injected into a blood vessel. The dye is concentrated in the urine, which outlines the kidneys, ureters, and bladder on the x-rays.

investigational      In clinical trials, refers to a drug (including a new drug, dose, combination, or route of administration) or procedure that has undergone basic laboratory testing and received approval from the US Food and Drug Administration (FDA) to be tested in human subjects. A drug or procedure may be approved by the FDA for use in one disease or condition, but be considered investigational in other diseases or conditions. Also called experimental.

IORT      Intraoperative radiation therapy. Radiation treatment aimed directly at a tumor during surgery.

IP      Intraperitoneal. Within the peritoneal cavity (the area that contains the abdominal organs).

IRB      Institutional Review Board. A group of scientists, doctors, clergy, and consumers at each health care facility that participates in a clinical trial. IRBs are designed to protect study participants. They review and must approve the action plan for every clinical trial. They check to see that the trial is well designed, does not involve undue risks, and includes safeguards for patients.

irradiation  (ih-RAY-dee-AY-shun)    The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or from materials called radioisotopes. Radioisotopes produce radiation and can be placed in or near the tumor or in the area near cancer cells. This type of radiation treatment is called internal radiation therapy, implant radiation, interstitial radiation, or brachytherapy. Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Irradiation is also called radiation therapy, radiotherapy, and x-ray therapy.

irreversible toxicity      Side effects that are caused by toxic substances or something harmful to the body and do not go away.

IV      Intravenous (in-tra-VEE-nus). Injected into a blood vessel.

Jewett staging system      A staging system for prostate cancer that uses ABCD. “A” and “B” refer to cancer that is confined to the prostate. “C” refers to cancer that has grown out of the prostate but has not spread to lymph nodes or other places in the body. “D” refers to cancer that has spread to lymph nodes or to other places in the body. Also called the ABCD rating or the Whitmore-Jewett staging system.

Karnofsky Performance Status      KPS. A standard way of measuring the ability of cancer patients to perform ordinary tasks. The Karnofsky Performance scores range from 0 to 100. A higher score means the patient is better able to carry out daily activities. KPS may be used to determine a patient's prognosis, to measure changes in a patient’s ability to function, or to decide if a patient could be included in a clinical trial.

KPS      Karnofsky Performance Status. A standard way of measuring the ability of cancer patients to perform ordinary tasks. The Karnofsky Performance scores range from 0 to 100. A higher score means the patient is better able to carry out daily activities. KPS may be used to determine a patient's prognosis, to measure changes in a patient’s ability to function, or to decide if a patient could be included in a clinical trial.

laparoscopy  (lap-a-RAHS-ko-pee)    The insertion of a thin, lighted tube (called a laparoscope) through the abdominal wall to inspect the inside of the abdomen and remove tissue samples.

laparotomy  (lap-a-RAH-toe-mee)    A surgical incision made in the wall of the abdomen.

large cell carcinoma  (kar-sin-O-ma)    Lung cancer in which the cells are large and look abnormal when viewed under a microscope.

lentinan      A beta-glucan (a type of polysaccharide) from the mushroom Lentinus edodes (shiitake mushroom). It has been studied in Japan as a treatment for cancer.

leptomeningeal      Having to do with the two innermost layers of tissues that cover the brain and spinal cord.

leptomeningeal cancer      A tumor that involves the tissues that cover the brain and spinal cord.

leptomeningeal metastases      Cancer that has spread from the original (primary) tumor to the tissues that cover the brain and spinal cord.

lesion  (LEE-zhun)    An area of abnormal tissue. A lesion may be benign (noncancercous) or malignant (cancerous).

leucopenia    See leucopenia.  

leukapheresis      Removal of the blood to collect specific blood cells; the remaining blood is returned to the body.

leukemia  (loo-KEE-mee-a)    Cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of blood cells to be produced and enter the bloodstream. 

leukocyte  (LOO-ko-site)    A white blood cell. Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.

leukopenia  (LOO-ko-PEE-nya)    A condition in which the number of leukocytes (white blood cells) in the blood is reduced.

lignan      A member of a group of substances found in plants that have shown estrogenic and anticancer effects. Lignans have been used in some cultures to treat certain medical problems.

limited-stage small cell lung cancer      Cancer is found in one lung, the tissues between the lungs, and nearby lymph nodes only.

linac      A machine that creates high-energy radiation to treat cancer, using electricity to form a stream of fast-moving subatomic particles. Also called mega-voltage (MeV) linear accelerator or a linear accelerator.

linear accelerator      A machine that creates high-energy radiation to treat cancer, using electricity to form a stream of fast-moving subatomic particles. Also called mega-voltage (MeV) linear accelerator or a linac.

linseed      The seed of the flax plant. It is a rich source of omega-3 fatty acid, fiber, and a compound called lignin. It is being studied in the prevention of prostate cancer. Also called flaxseed. 

liver metastases      Cancer that has spread from the original (primary) tumor to the liver.

local cancer      An invasive malignant cancer confined entirely to the organ where the cancer began.

local therapy      Treatment that affects cells in the tumor and the area close to it.

localized      Restricted to the site of origin, without evidence of spread.

locally advanced cancer      Cancer that has spread only to nearby tissues or lymph nodes.

low grade      When referring to cancerous and precancerous growths, a term used to describe cells that look nearly normal under a microscope. These cells are less likely to grow and spread quickly than cells in high-grade cancerous or precancerous growths.

lower GI series      X-rays of the colon and rectum (lower gastrointestinal tract) that are taken after a person is given a barium enema.

lumbar puncture      A procedure in which a needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give anticancer drugs intrathecally. Also called a spinal tap. 

lymph  (limf)    The clear fluid that travels through the lymphatic system and carries cells that help fight infections and other diseases. Also called lymphatic fluid. 

lymph gland      A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph glands filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called a lymph node. 

lymph node  (limf node)    A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called a lymph gland.

lymphocyte  (LIM-fo-site)    A type of white blood cell. Lymphocytes have a number of roles in the immune system, including the production of antibodies and other substances that fight infection and diseases. 

lymphocytic leukemia      A type of cancer in which the bone marrow makes too many lymphocytes (white blood cells).

lymphoma  (lim-FO-ma)    Cancer that begins in cells of the immune system. There are two basic categories of lymphomas. One kind is Hodgkin's lymphoma, which is marked by the presence of a type of cell called the Reed-Sternberg cell. The other category is non-Hodgkin's lymphomas, which includes a large, diverse group of cancers of immune system cells. Non-Hodgkin's lymphomas can be further divided into cancers that have an indolent (slowly progressing) course and those that have an aggressive (rapidly progressing) course. These subtypes behave and respond to treatment differently. Both Hodgkin's and non-Hodgkin's lymphomas can occur in children and adults, and prognosis and treatment depend on the stage and the type of cancer. 

lytic      Having to do with lysis. In biology, lysis refers to the disintegration of a cell by disruption of its plasma membrane. Lysis can be caused by chemical or physical means (e.g., high-energy sound waves) or by a virus infection.

magnetic resonance imaging  (mag-NET-ik REZ-o-nans IM-a-jing)    MRI. A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as CT or x-ray. MRI is especially useful for imaging the brain, spine, the soft tissue of joints, and the inside of bones. Also called nuclear magnetic resonance imaging. 

maintenance therapy      Treatment that is given to help a primary (original) treatment keep working. Maintenance therapy is often given to help keep cancer in remission.

malignant  (ma-LIG-nant)    Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

malignant ascites      A condition in which fluid containing cancer cells collects in the abdomen.

malignant meningioma      A rare, quickly growing tumor that occurs in the membranes that cover and protect the brain and spinal cord (meninges).

malignant mesothelioma      A rare type of cancer in which malignant cells are found in the sac lining the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.

mammogram  (MAM-o-gram)    An x-ray of the breast.

mammography  (mam-OG-ra-fee)    The use of x-rays to create a picture of the breast.

margin      The edge or border of the tissue removed in cancer surgery. The margin is described as negative or clean when the pathologist finds no cancer cells at the edge of the tissue, suggesting that all of the cancer has been removed. The margin is described as positive or involved when the pathologist finds cancer cells at the edge of the tissue, suggesting that all of the cancer has not been removed.

mastectomy  (mas-TEK-toe-mee)    Surgery to remove the breast (or as much of the breast tissue as possible).

matrix metalloproteinase      A member of a group of enzymes that can break down proteins, such as collagen, that are normally found in the spaces between cells in tissues (i.e., extracellular matrix proteins). Because these enzymes need zinc or calcium atoms to work properly, they are called metalloproteinases. Matrix metalloproteinases are involved in wound healing, angiogenesis, and tumor cell metastasis.

measurable disease      A tumor that can be accurately measured in size. This information can be used to judge response to treatment.

median      A statistics term. The middle value in a set of measurements.  

median survival time      The time from either diagnosis or treatment at which half of the patients with a given disease are found to be, or expected to be, still alive. In a clinical trial, median survival time is one way to measure how effective a treatment is.

medulloblastoma  (MED-yoo-lo-blas-TOE-ma)    A malignant brain tumor that begins in the lower part of the brain and that can spread to the spine or to other parts of the body. Medulloblastomas are a type of primitive neuroectodermal tumor (PNET).

mega-voltage linear accelerator      MeV linear accelerator. A machine that creates high-energy radiation to treat cancer, using electricity to form a stream of fast-moving subatomic particles. Also called linear accelerator or a linac.

meningeal      Refers to the meninges, the tissue covering the brain and spinal cord.

meningeal metastases      Cancer that has spread from the original (primary) tumor to the tissue covering the brain, spinal cord, or both.

meninges  (meh-NIN-jeez)    The three membranes that cover and protect the brain and spinal cord.

meningioma  (meh-nin-jee-O-ma)    A type of tumor that occurs in the meninges, the membranes that cover and protect the brain and spinal cord. Meningiomas usually grow slowly.

mesothelioma      A benign (noncancerous) or malignant (cancerous) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the air increases the risk of developing malignant mesothelioma.

metastasis  (meh-TAS-ta-sis)    The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-ta-seez).

metastasize  (meh-TAS-ta-size)    To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

metastatic  (MET-uh-STAT-ik)    Having to do with metastasis, which is the spread of cancer from one part of the body to another.

metastatic cancer      Cancer that has spread from the place in which it started to other parts of the body.

micrometastases      Small numbers of cancer cells that have spread from the primary tumor to other parts of the body and are too few to be picked up in a screening or diagnostic test.

microwave thermotherapy      A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs. Also called microwave therapy. 

milk thistle      A plant that has been used in some cultures to treat certain medical problems, including stomach, liver, and gallbladder disorders. The active extract of milk thistle seeds is called silymarin. It is being studied in the prevention of liver damage caused by some cancer treatments. Also called Silybum marianum.

Miraluma test      A type of breast imaging test that is used to detect cancer cells in the breasts of some women who have had abnormal mammograms, or who have dense breast tissue. The Miraluma test is not used for screening, or in place of a mammogram. In this test, a woman receives an injection of a small amount of a radioactive substance called technetium 99, which is taken up by cancer cells, and a gamma camera is used to take pictures of the breasts. Also called scintimammography and sestamibi breast imaging.

mistletoe      A semiparasitic plant that grows on some types of trees. Mistletoe extracts are being studied as treatments for cancer. 

mixed glioma      A brain tumor that occurs in more than one type of brain cell, including astrocytes, ependymal cells, and oligodendrocytes.

modality      A method of treatment. For example, surgery and chemotherapy are treatment modalities. 

modified radical mastectomy  (mas-TEK-toe-mee)    Surgery for breast cancer in which the breast, most or all of the lymph nodes under the arm, and the lining over the chest muscles are removed. Sometimes the surgeon also removes part of the chest wall muscles.

monoclonal antibody  (MAH-no-KLO-nul AN-tih-BAH-dee)    A laboratory-produced substance that can potentially locate and bind to cancer cells wherever they are in the body. Many monoclonal antibodies are used in cancer detection or therapy; each one recognizes a different protein on certain cancer cells. Monoclonal antibodies can be used alone, or they can be used to deliver drugs, toxins, or radioactive material directly to a tumor.

morbidity      A disease or the incidence of disease within a population. Morbidity also refers to adverse effects caused by a treatment.

Morinda citrifolia      A tropical shrub. An extract from the fruit is being studied as a treatment for cancer, and extracts from the fruit, leaves, or roots have been used in some cultures to treat other diseases. Also called noni.

MRI      Magnetic resonance imaging (mag-NET-ik REZ-o-nans IM-a-jing). A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as CT or x-ray. MRI is especially useful for imaging the brain, spine, the soft tissue of joints, and the inside of bones. Also called nuclear magnetic resonance imaging. 

mucositis      A complication of some cancer therapies in which the lining of the digestive system becomes inflamed. Often seen as sores in the mouth.

multicenter study      A clinical trial that is carried out at more than one medical institution.

mutate      To change the genetic material of a cell. The changes (mutations) can be harmful, beneficial, or have no effect.

mutation      Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

myalgia  (my-AL-juh)    Pain in a muscle or group of muscles.

myelin  (MYE-eh-lin)    The fatty substance that covers and protects nerves.

myelogram  (MY-eh-lo-gram)    An x-ray of the spinal cord after an injection of dye into the space between the lining of the spinal cord and brain.

myeloid  (MY-eh-loyd)    Having to do with or resembling the bone marrow. May also refer to certain types of hematopoietic (blood-forming) cells found in the bone marrow. Sometimes used as a synonym for myelogenous; for example, acute myeloid leukemia and acute myelogenous leukemia are the same disease.

myelosuppression      A condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets. Myelosuppression is a side effect of some cancer treatments. When myelosuppression is severe, it is called myeloablation.

natural killer cell      NK cell. A type of white blood cell that contains granules with enzymes that can kill tumor cells or microbial cells. Also called a large granular lymphocyte.

necrosis  (ne-KRO-sis)    Refers to the death of living tissues. 

needle biopsy      The removal of tissue or fluid with a needle for examination under a microscope. Also called fine-needle aspiration.

neoadjuvant therapy  (NEE-o-AD-joo-vant)    Treatment given before the primary treatment. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy. 

neoplasia  (NEE-o-PLAY-zha)    Abnormal and uncontrolled cell growth.

neoplasm      An abnormal mass of tissue that results from excessive cell division. Neoplasms may be benign (not cancerous), or malignant (cancerous). Also called tumor.

neoplastic meningitis      A condition in which cancer cells spread into the meninges (membranes that surround the brain and spinal cord). 

nephrectomy  (neh-FREK-tuh-mee)    Surgery to remove a kidney or part of a kidney. In a partial nephrectomy, part of one kidney or a tumor is removed, but not an entire kidney. In a simple nephrectomy, one kidney is removed. In a radical nephrectomy, an entire kidney, nearby adrenal gland and lymph nodes, and other surrounding tissue are removed. In a bilateral nephrectomy, both kidneys are removed.

nephrotoxicity    Being toxic or destructive to kidney cells.

neuroblastoma      Cancer that arises in immature nerve cells and affects mostly infants and children.

neurocognitive      Having to do with the ability to think and reason. This includes the ability to concentrate, remember things, process information, learn, speak, and understand.

neuroectodermal tumor      A tumor of the central or peripheral nervous system.

neuropathy      A problem in peripheral nerve function (any part of the nervous system except the brain and spinal cord) that causes pain, numbness, tingling, swelling, and muscle weakness in various parts of the body. Neuropathies may be caused by physical injury, infection, toxic substances, disease (e.g., cancer, diabetes, kidney failure, or malnutrition), or drugs such as anticancer drugs. Also called peripheral neuropathy.

neurotoxicity      The tendency of some treatments to cause damage to the nervous system.

neutropenia      An abnormal decrease in the number of neutrophils, a type of white blood cell.

neutrophil  (NOO-tro-fil)    A type of white blood cell.

node-negative      Cancer that has not spread to the lymph nodes.

node-positive      Cancer that has spread to the lymph nodes.

non-Hodgkin's lymphoma      A group of cancers of the lymphoid system, including B-cell lymphoma, Burkitt's lymphoma, diffuse cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, lymphoblastic lymphoma, mantle cell lymphoma, mycosis fungoides, post-transplantation lymphoproliferative disorder, small non-cleaved cell lymphoma, and T-cell lymphoma.

non-small cell lung cancer      A group of lung cancers that includes squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.

noni      Morinda citrifolia. A tropical shrub. An extract from the fruit is being studied as a treatment for cancer, and extracts from the fruit, leaves, or roots have been used in some cultures to treat other diseases. 

nonrandomized clinical trial      A clinical trial in which the participants are not assigned by chance to different treatment groups. Participants may choose which group they want to be in, or they may be assigned to the groups by the researchers.

objective improvement      An improvement that can be measured by the health care provider (for example, a decrease in pain can be measured by how much pain medicine the patient is taking).

objective response      A measurable response.

occult stage non-small cell lung cancer      Cancer cells are found in sputum (mucus coughed up from the lungs), but no tumor can be found in the lung by imaging or bronchoscopy, or the primary tumor is too small to be assessed.

off-label      Describes the use of a prescription drug to treat a disease or condition for which the drug has not been approved by the US Food and Drug Administration.

oligoastrocytoma      A rare type of brain tumor made up of two kinds of cells, oligodendrocytes and astrocytes, which are brain cells that nourish and support nerve cells. Also called mixed glioma. 

oligodendroglial tumor      A rare, slow-growing tumor that begins in the oligodendrocytes (brain cells that nourish and support nerve cells). Also called an oligodendroglioma.

oligodendroglioma  (OL-ih-go-den-dro-glee-O-ma)    A rare, slow-growing tumor that begins in the oligodendrocytes (brain cells that nourish and support nerve cells). Also called an oligodendroglial tumor.

omega-3 fatty acid      A type of fat obtained in the diet and involved in immunity.

Ommaya reservoir  (o-MY-a REZ-er-vwahr)    A device surgically placed under the scalp and used to deliver anticancer drugs to the fluid surrounding the brain and spinal cord.

oncologist  (on-KOL-o-jist)    A doctor who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment. For example, a radiation oncologist specializes in treating cancer with radiation.

oncology      The study of cancer.

oncolysis      The breakdown, or lysis, of a tumor. This can occur by mechanical means, chemicals, or infectious agents such as viruses. Oncolytic viruses do not lyse most normal cells.

open label study      A type of study in which both the health providers and the patients are aware of the drug or treatment being given.

operable      Describes a condition that can be treated by surgery.

opportunistic infection      An infection caused by an organism that does not normally cause disease. Opportunistic infections occur in people with weakened immune systems.

osteosarcoma  (AHS-tee-o-sar-KO-ma)    A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young people and affects more males than females. Also called osteogenic sarcoma.

ototoxicity    Being poisonous to or exerting a deleterious effect upon the eighth nerve or upon the organs of hearing and balance.

outpatient      A patient who visits a health care facility for diagnosis or treatment without spending the night. Sometimes called a day patient.

overall survival      The percentage of subjects in a study who have survived for a defined period of time. Usually reported as time since diagnosis or treatment. Also called the survival rate. 

p-value      A statistics term. A measure of probability that a difference between groups during an experiment happened by chance. For example, a p-value of .01 (p = .01) means there is a 1 in 100 chance the result occurred by chance. The lower the p-value, the more likely it is that the difference between groups was caused by treatment.

p53 gene      A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.

palliative care  (PAL-ee-yuh-tiv)    Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of palliative care is to prevent or treat as early as possible the symptoms of the disease, side effects caused by treatment of the disease, and psychological, social, and spiritual problems related to the disease or its treatment. Also called comfort care, supportive care, and symptom management. 

palliative therapy  (PAL-ee-yuh-tiv)    Treatment given to relieve the symptoms and reduce the suffering caused by cancer and other life-threatening diseases. Palliative cancer therapies are given together with other cancer treatments, from the time of diagnosis, through treatment, survivorship, recurrent or advanced disease, and at the end of life.

pancreatic cancer      A disease in which malignant (cancer) cells are found in the tissues of the pancreas. Also called exocrine cancer.

paresis    Slight or incomplete paralysis.

paresthesias      Abnormal touch sensations, such as burning or prickling, that occur without an outside stimulus.

partial remission      A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment. Also called partial response.

partial response      A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment.

pathologist  (pa-THOL-o-jist)    A doctor who identifies diseases by studying cells and tissues under a microscope.

pathology report      The description of cells and tissues made by a pathologist based on microscopic evidence, and sometimes used to make a diagnosis of a disease.

patient advocate      A person who helps a patient work with others who have an effect on the patient's health, including doctors, insurance companies, employers, case managers, and lawyers. A patient advocate helps resolve issues about health care, medical bills, and job discrimination related to a patient's medical condition. Cancer advocacy groups try to raise public awareness about important cancer issues, such as the need for cancer support services, education, and research. Such groups work to bring about change that will help cancer patients and their families.

pediatric  (pee-dee-AT-rik)    Having to do with children.

performance status      A measure of how well a patient is able to perform ordinary tasks and carry out daily activities.

perfusion      Bathing an organ or tissue with a fluid. In regional perfusion, a specific area of the body (usually an arm or a leg) receives high doses of anticancer drugs through a blood vessel. Such a procedure is performed to treat cancer that has not spread.

perioperative      Around the time of surgery; usually lasts from the time of going into the hospital or doctor's office for surgery until the time the patient goes home.

peripheral blood      Blood circulating throughout the body.

peripheral neuropathy      A condition of the nervous system that causes numbness, tingling, burning or weakness. It usually begins in the hands or feet, and can be caused by certain anticancer drugs.

PET scan      Positron emission tomography scan. A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body.

phase I trial      The first step in testing a new treatment in humans. These studies test the best way to give a new treatment (for example, by mouth, intravenous infusion, or injection) and the best dose. The dose is usually increased a little at a time in order to find the highest dose that does not cause harmful side effects. Because little is known about the possible risks and benefits of the treatments being tested, phase I trials usually include only a small number of patients who have not been helped by other treatments.

phase I/II trial      A trial to study the safety, dosage levels, and response to a new treatment.

phase II trial      A study to test whether a new treatment has an anticancer effect (for example, whether it shrinks a tumor or improves blood test results) and whether it works against a certain type of cancer.

phase II/III trial      A trial to study response to a new treatment and the effectiveness of the treatment compared with the standard treatment regimen.

phase III trial      A study to compare the results of people taking a new treatment with the results of people taking the standard treatment (for example, which group has better survival rates or fewer side effects). In most cases, studies move into phase III only after a treatment seems to work in phases I and II. Phase III trials may include hundreds of people.

phase IV trial      After a treatment has been approved and is being marketed, it is studied in a phase IV trial to evaluate side effects that were not apparent in the phase III trial. Thousands of people are involved in a phase IV trial.

phenylacetate      A drug being studied in the treatment of cancer.

phenylbutyrate      An anticancer drug that belongs to the family of drugs called differentiating agents.

pheresis  (fer-E-sis)    A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor. Also called apheresis.

Philadelphia chromosome      An abnormality of chromosome 22 in which part of chromosome 9 is transferred to it. Bone marrow cells that contain the Philadelphia chromosome are often found in chronic myelogenous leukemia.

phlebitis    Inflammation of a vein.

phlebotomy      The puncture of a vein with a needle for the purpose of drawing blood. Also called venipuncture. 

photodynamic therapy  (foe-toe-dye-NAM-ik)    Treatment with drugs that become active when exposed to light. These drugs kill cancer cells.

photopheresis      A procedure in which blood is treated outside the body, with ultraviolet light and drugs that become active when exposed to light, and then returned to the body. It is being studied as a treatment for some blood and bone marrow diseases and graft-versus-host disease (GVHD). Also called extracorporeal photophoresis. 

pilocytic  (PI-lo-SIT-ik)    Made up of cells that look like fibers when viewed under a microscope.

pilot study      The initial study examining a new method or treatment.

pineoblastoma  (PIN-ee-o-blas-TOE-ma)    A fast growing type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

placebo-controlled      Refers to a clinical study in which the control patients receive a placebo.

plasma  (PLAS-ma)    The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.

platelet  (PLAYT-let)    A type of blood cell that helps prevent bleeding by causing blood clots to form. Also called a thrombocyte.

PNET      Primitive neuroectodermal tumor. One of a group of cancers that develop from the same type of early cells, and share certain biochemical and genetic features. Some PNETs develop in the brain and central nervous system (CNS-PNET), and others develop in sites outside of the brain such as the limbs, pelvis, and chest wall (peripheral PNET). 

polymerase chain reaction      PCR. A laboratory method used to make many copies of a specific DNA sequence.

pons      Part of the central nervous system, located at the base of the brain, between the medulla oblongata and the midbrain. It is part of the brainstem.

port-a-cath      An implanted device through which blood may be withdrawn and drugs may be infused without repeated needle sticks. Also called a port.

positron emission tomography scan      PET scan. A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body. 

postmortem      After death. Often used to describe an autopsy.

postoperative      After surgery.

PR+      Progesterone receptor positive. Breast cancer cells that have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR+ need the hormone progesterone to grow and will usually respond to hormonal therapy.

PR-      Progesterone receptor negative. Breast cancer cells that do not have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR- do not need the hormone progesterone to grow and usually do not respond to hormonal therapy.

preclinical study      Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

primary tumor      The original tumor.

primitive neuroectodermal tumor      PNET. One of a group of cancers that develop from the same type of early cells, and share certain biochemical and genetic features. Some PNETs develop in the brain and central nervous system (CNS-PNET), and others develop in sites outside of the brain such as the limbs, pelvis, and chest wall (peripheral PNET). 

progression      Increase in the size of a tumor or spread of cancer in the body.

progression-free survival      One type of measurement that can be used in a clinical study or trial to help determine whether a new treatment is effective. It refers to the probability that a patient will remain alive, without the disease getting worse.

progressive disease      Cancer that is increasing in scope or severity.

prospective cohort study      A research study that follows over time groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) and compares them for a particular outcome (such as lung cancer).

prostate  (PROS-tate)    A gland in the male reproductive system just below the bladder. The prostate surrounds part of the urethra (the canal that empties the bladder) and produces a fluid that forms part of semen.

prostate-specific antigen test      A blood test that measures the level of prostate-specific antigen (PSA), a substance produced by the prostate and some other tissues in the body. Increased levels of PSA may be a sign of prostate cancer.

prostatectomy  (pros-ta-TEK-toe-mee)    An operation to remove part or all of the prostate. Radical (or total) prostatectomy is the removal of the entire prostate and some of the tissue around it.

protocol      An action plan for a clinical trial. The plan states what the study will do, how, and why. It explains how many people will be in it, who is eligible to participate, what study agents or other interventions they will be given, what tests they will receive and how often, and what information will be gathered.

proton beam radiation therapy  (…ray-dee-AY-shun…)    A type of radiation therapy that uses protons generated by a special machine. A proton is a type of high-energy radiation that is different from an x-ray.

PSA      Prostate-specific antigen. A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.

pulmonary      Relating to the lungs.

quality of life      The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual's sense of well-being and ability to carry out various tasks. 

radiation  (ray-dee-AY-shun)    Energy released in the form of particles or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, and medical x-rays.

radiation physicist      A person who makes sure that the radiation machine delivers the right amount of radiation to the correct site in the body. The physicist works with the radiation oncologist to choose the treatment schedule and dose that has the best chance of killing the most cancer cells.

radiation surgery      A radiation therapy technique that delivers radiation directly to the tumor while sparing the healthy tissue. Also called radiosurgery and stereotactic external beam irradiation.

radiation therapy  (ray-dee-AY-shun THER-ah-pee)    The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Also called radiotherapy.

radical mastectomy  (RAD-ih-kul mas-TEK-toe-mee)    Surgery for breast cancer in which the breast, chest muscles, and all of the lymph nodes under the arm are removed. For many years, this was the breast cancer operation used most often, but it is used rarely now. Doctors consider radical mastectomy only when the tumor has spread to the chest muscles. Also called the Halsted radical mastectomy.

radical nephrectomy  (RAD-ih-kul neh-FREK-toe-mee)    Surgery to remove an entire kidney, nearby adrenal gland and lymph nodes, and other surrounding tissue. 

radioactive iodine  (RAY-dee-o-AK-tiv EYE-uh-dine)    A radioactive form of iodine, often used for imaging tests or as a treatment for thyroid cancer and certain other cancers. For imaging tests, the patient takes a small dose of radioactive iodine that collects in thyroid cells and certain kinds of tumors and can be detected by a scanner. For treatment of thyroid cancer, the patient takes a large dose of radioactive iodine, which kills thyroid cells. Radioactive iodine is also used in internal radiation therapy for prostate cancer, intraocular (eye) melanoma, and carcinoid tumors. The radioactive iodine is given by infusion or sealed in seeds, which are placed in or near the tumor to kill cancer cells. 

radioactive seed      A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material decays (breaks down).

radioimmunotherapy      Treatment with a radioactive substance that is linked to an antibody that will attach to the tumor when injected into the body.

radiolabeled      Any compound that has been joined with a radioactive substance.

radiologist  (RAY-dee-OL-o-jist)    A doctor who specializes in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, sound waves, or other types of energy.

radiology      The use of radiation (such as x-rays) or other imaging technologies (such as ultrasound and magnetic resonance imaging) to diagnose or treat disease.

radionecrosis    Destruction of tissue or ulceration caused by radiation.

radiopharmaceutical      A drug containing a radioactive substance that is used in the diagnosis and treatment of cancer and in pain management of bone metastases. Also called a radioactive drug.

radiosurgery      A radiation therapy technique that delivers radiation directly to the tumor while sparing the healthy tissue. Also called radiation surgery and stereotactic external beam irradiation.

radiotherapy  (RAY-dee-o-THER-a-pee)    The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiotherapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Also called radiation therapy.

randomization      When referring to an experiment or clinical trial, the process by which animal or human subjects are assigned by chance to separate groups that compare different treatments or other interventions. Randomization gives each participant an equal chance of being assigned to any of the groups. 

randomized clinical trial      A study in which the participants are assigned by chance to separate groups that compare different treatments; neither the researchers nor the participants can choose which group. Using chance to assign people to groups means that the groups will be similar and that the treatments they receive can be compared objectively. At the time of the trial, it is not known which treatment is best. It is the patient's choice to be in a randomized trial.

RBC      Red blood cell. RBCs carry oxygen to all parts of the body.

rectum      The last several inches of the large intestine. The rectum ends at the anus.

recur      To occur again.

recurrence      The return of cancer, at the same site as the original (primary) tumor or in another location, after the tumor had disappeared.

recurrent cancer      Cancer that has returned after a period of time during which the cancer could not be detected. The cancer may come back to the same site as the original (primary) tumor or to another place in the body.

red blood cell      RBC. A cell that carries oxygen to all parts of the body. Also called an erythrocyte.

red clover      Trifolium pratense. A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover and wild clover.

refractory      In medicine, describes a disease or condition that does not respond to treatment. 

refractory cancer      Cancer that has not responded to treatment.

regimen      A treatment plan that specifies the dosage, the schedule, and the duration of treatment.

regression      A decrease in the size of a tumor or in the extent of cancer in the body.

relapse      The return of signs and symptoms of cancer after a period of improvement.

relative survival rate      A specific measurement of survival. For cancer, the rate is calculated by adjusting the survival rate to remove all causes of death except cancer. The rate is determined at specific time intervals, such as 2 years and 5 years after diagnosis.

remission      A decrease in or disappearance of signs and symptoms of cancer. In partial remission, some, but not all, signs and symptoms of cancer have disappeared. In complete remission, all signs and symptoms of cancer have disappeared, although cancer still may be in the body.

remote brachytherapy      A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote brachytherapy or high-dose-rate remote radiation therapy.

resectable  (ree-SEK-tuh-bull)    Part or all of an organ that can be removed with surgery.

resected      Surgical removal of part or all of an organ.

resection  (ree-SEK-shun)    Removal of tissue or part or all of an organ by surgery.

residual disease      Cancer cells that remain after attempts to remove the cancer have been made.

resistance      Failure of a cancer to shrink after treatment.

response     The shrinking of a tumor with cancer therapy.

response rate      The percentage of patients whose cancer shrinks or disappears after treatment.

retinoblastoma      An eye cancer that most often occurs in children younger than 5 years. It occurs in hereditary and nonhereditary (sporadic) forms.

retinoid      Vitamin A or a vitamin A-like compound.

retinol      Vitamin A. It is essential for proper vision and healthy skin and mucous membranes. Retinol is being studied for cancer prevention; it belongs to the family of drugs called retinoids.

retrospective study      A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls). Researchers study the medical and lifestyle histories of the people in each group to learn what factors may be associated with the disease or condition. For example, one group may have been exposed to a particular substance that the other was not. Also called a case-control study. 

rhabdoid tumor      A malignant tumor of either the central nervous system (CNS) or the kidney. Malignant rhabdoid tumors of the CNS often have an abnormality of chromosome 22. These tumors usually occur in children younger than 2 years.

rhabdomyosarcoma      A malignant tumor of muscle tissue.

rush    A powerful wave of contractile activity which travels extremely long distances down the small intestines; it is caused by intense irritation or unusual distension.

sarcoma      A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

scan      A picture of structures inside the body. Scans often used in diagnosing, staging, and monitoring disease include liver scans, bone scans, and computed tomography (CT) or computerized axial tomography (CAT) scans and magnetic resonance imaging (MRI) scans. In liver scanning and bone scanning, radioactive substances that are injected into the bloodstream collect in these organs. A scanner that detects the radiation is used to create pictures. In CT scanning, an x-ray machine linked to a computer is used to produce detailed pictures of organs inside the body. MRI scans use a large magnet connected to a computer to create pictures of areas inside the body.

schedule      In clinical trials, the step-by-step plan for how patients are to be treated; for example, which drugs are to be given, the order and method by which they are to be given, the length of time of each infusion, the amount of time between courses, and the total length of treatment.

second-line therapy      Treatment that is given when initial treatment (first-line therapy) doesn’t work, or stops working.

second-look surgery      Surgery performed after primary treatment to determine whether tumor cells remain.

secondary cancer      A term that is used to describe either a new primary cancer or cancer that has spread from the place in which it started to other parts of the body. 

sedimentation rate      The distance red blood cells travel in one hour in a sample of blood as they settle to the bottom of a test tube. The sedimentation rate is increased in inflammation, infection, cancer, rheumatic diseases, and diseases of the blood and bone marrow. Also called erythrocyte sedimentation rate. 

selection bias      An error in choosing the individuals or groups to take part in a study. Ideally, the subjects in a study should be very similar to one another and to the larger population from which they are drawn (for example, all individuals with the same disease or condition). If there are important differences, the results of the study may not be valid.

sepsis  (SEP-sis)    The presence of bacteria or their toxins in the blood or tissues.

SGOT      Serum glutamic-oxaloacetic transaminase. An enzyme found in the liver, heart, and other tissues. A high level of SGOT released into the blood may be a sign of liver or heart damage, cancer, or other diseases. Also called aspartate transaminase. 

shunt      A surgeon implants or creates a shunt to move blood or other fluid from one part of the body to another part. For example, a surgeon may implant a tube to drain cerebrospinal fluid from the brain to the abdomen. A surgeon may also change normal blood flow by joining two blood vessels together. 

simulation      In cancer treatment, a process used to plan radiation therapy so that the target area is precisely located and marked.

somnolence     Sleepiness or unnatural drowsiness.

spinal tap      A procedure in which a needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called a lumbar puncture.

spleen      An organ that is part of the lymphatic system. The spleen produces lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen near the stomach. 

stable disease      Cancer that is neither decreasing nor increasing in extent or severity.

stage      The extent of a cancer within the body. If the cancer has spread, the stage describes how far it has spread from the original site to other parts of the body.

stage 0 bladder cancer      Cancer is found on tissue lining the inside of the bladder only. Stage 0 is divided into stage 0a and stage 0is, depending on the type of the tumor. Stage 0a is also called papillary carcinoma, which may look like tiny mushrooms growing from the lining of the bladder. Stage 0is is also called carcinoma in situ, which is a flat tumor on the tissue lining the inside of the bladder.

stage 0 cervical cancer      Cancer is found in the first layer of cells lining the cervix only and has not invaded the deeper tissues of the cervix. Also called carcinoma in situ.

stage 0 chronic lymphocytic leukemia      There are too many lymphocytes in the blood, but there are no other symptoms of leukemia. Stage 0 is indolent (slow-growing).

stage 0 colorectal cancer      Cancer is found in the innermost lining of the colon and/or rectum only. Also called carcinoma in situ.

stage 0 esophageal cancer      Cancer is found in the innermost layer of cells lining the esophagus. Also called carcinoma in situ.

stage 0 gastric cancer      Cancer is found in the inside lining of the mucosal (innermost) layer of the stomach wall. Also called carcinoma in situ.

stage 0 melanoma      Cancer is found in the epidermis (outer layer of the skin) only. Also called melanoma in situ.

stage 0 nasopharyngeal cancer      Cancer is found in the lining of the nasopharynx (the upper part of the throat behind the nose) only. Also called carcinoma in situ.

stage 0 non-small cell lung cancer      Cancer is limited to the lung. It is found in a few layers of cells only, and has not grown through the top lining of the lung. Also called carcinoma in situ.

stage 0 skin cancer      Cancer is found in the epidermis (topmost layer of the skin) only, in the layer of cells in which the cancer began. Also called carcinoma in situ. 

stage 0 testicular cancer      Abnormal cells are found only in the tiny tubules where the sperm cells begin to develop. The cells do not invade normal tissues; all tumor marker levels are normal. Sometimes called a precancerous condition. Also called carcinoma in situ.

stage I adrenocortical cancer      Cancer that is smaller than 5 centimeters (smaller than 2 inches) and has not spread into tissues around the adrenal gland.

stage I adult Hodgkin's lymphoma      Stage I is divided into stage I and stage IE. In stage I, cancer is found in a single group of lymph nodes. In stage IE, cancer is found in one area or organ other than the lymph nodes.

stage I adult non-Hodgkin's lymphoma      Stage I is divided into stage I and stage IE. In stage I, cancer is found in a single lymph node area. In stage IE, cancer is found in an organ or tissue other than the lymph nodes. 

stage I adult primary liver cancer      One tumor is present, which is no larger than 2 centimeters. 

stage I anal cancer      Cancer that has spread beyond the top layer of anal tissue and is smaller than 2 centimeters (smaller than 1 inch).

stage I bladder cancer      Cancer has spread to the connective tissue layer below the inner lining of the bladder.

stage I breast cancer      The tumor is no larger than 2 centimeters and has not spread outside the breast.

stage I cancer of the uterus      Cancer found in only the main part of the uterus, not the cervix.

stage I cancer of the vulva      Cancer found in the vulva only or the space between the opening of the rectum and the vagina (perineum). The tumor is 2 centimeters (about 1 inch) or smaller.

stage I cervical cancer      Cancer is found in the cervix only. Stage I is divided into stages IA and IB, based on the amount of cancer that is found. In stage IA, a very small amount of cancer that can only be seen with a microscope is found in the tissues of the cervix. The cancer is not deeper than 5 millimeters and not wider than 7 millimeters. In stage IB, the cancer is still within the cervix and either (1) can only be seen with a microscope and is deeper than 5 millimeters or wider than 7 millimeters; or (2) can be seen without a microscope and may be larger than 4 centimeters.

stage I childhood non-Hodgkin's lymphoma      Cancer is found in a single area or lymph node outside of the abdomen or chest.

stage I chronic lymphocytic leukemia      There are too many lymphocytes in the blood and the lymph nodes are larger than normal.

stage I colorectal cancer      Cancer has spread beyond the innermost lining of the colon and/or rectum to the second and third layers and involves the inside wall of the colon and/or rectum, but it has not spread to the outer wall or outside the colon and/or rectum. Also called Dukes' A colorectal cancer.

stage I cutaneous T-cell lymphoma      May be either of the following: (1) stage IA cancer affecting less than 10% of the skin's surface and appearing as red, dry, scaly patches; (2) stage IB cancer affecting 10% or more of the skin's surface and appearing as red, dry, scaly patches.

stage I endometrial cancer      Cancer is found in the uterus only. Stage I is divided into stages IA, IB, and IC, based on how far the disease has spread from the endometrium into the muscles of the uterus.

stage I esophageal cancer      Cancer has spread beyond the innermost layer of cells to the next layer of tissue in the wall of the esophagus.

stage I gastric cancer      Stage I is divided into stage IA and stage IB, depending on where the cancer has spread. In stage IA, cancer has spread completely through the mucosal (innermost) layer of the stomach wall. In stage IB, cancer has spread completely through the mucosal (innermost) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor, or has spread to the muscularis (middle) layer of the stomach wall. 

stage I hypopharynx cancer      Tumor that is confined to one area of the hypopharynx and is no larger than 2 centimeters (about 0.75 inch).

stage I kidney cancer      A tumor that is 7 centimeters (2.75 inches) or smaller.

stage I laryngeal cancer      Cancer that is only in the area where it started and has not spread to nearby lymph nodes or other parts of the body. The exact definition of stage I depends on whether the cancer started in the supraglottis (cancer in only one area of the supraglottis, and the vocal cords can move normally); the glottis (cancer in only the vocal cords, and the vocal cords can move normally); or the subglottis (cancer that has not spread outside the subglottis).

stage I lip and oral cavity cancer      Cancer that is no larger than 2 centimeters (about 1 inch) and has not spread to nearby lymph nodes.

stage I melanoma      Stage I is divided into stages IA and IB. In stage IA, the tumor is not more than 1 millimeter thick, with no ulceration. The tumor is in the epidermis (outer layer of skin) and upper layer of the dermis (inner layer of skin). In stage IB, the tumor is either not more than 1 millimeter thick, with ulceration, and may have spread into the dermis or the tissue below the skin; or 1 to 2 millimeters thick, with no ulceration.

stage I mesothelioma      Cancer found in the lining of the chest cavity near the lung and heart, in the diaphragm (the thin muscle below the lungs and heart that separates the chest from the abdomen), or in the lung.

stage I multiple myeloma      Relatively few cancer cells have spread throughout the body. There may be no symptoms of disease.

stage I nasopharyngeal cancer      Cancer is found in the nasopharynx (the upper part of the throat behind the nose) only.

stage I non-small cell lung cancer      Cancer is in the lung only. Stage I is divided into stages IA and IB based on the size or location of the tumor.

stage I oropharynx cancer      Cancer that is no larger than 2 centimeters (about 0.75 inch) and is confined to the oropharynx.

stage I ovarian cancer      Cancer is found in one or both of the ovaries and has not spread. Stage I is divided into stage IA, stage IB, and stage IC. In stage IA, cancer is found in a single ovary. In stage IB, cancer is found in both ovaries. In stage IC, cancer is found in one or both ovaries and one of the following is true: cancer is found on the outside surface of one or both ovaries; the capsule (outer covering) of the tumor has ruptured (broken open); or, cancer cells are found in fluid from the peritoneal cavity (the body cavity that contains most of the organs in the abdomen).

stage I pancreatic cancer      Cancer is found in the pancreas only. Stage I is divided into stage IA and stage IB based on tumor size. In stage IA, the tumor is no larger than 2 centimeters and in stage IB, the tumor is larger than 2 centimeters.

stage I prostate cancer      Cancer is found in the prostate only. It cannot be felt during a digital rectal exam and is not visible by imaging. It is usually found accidentally during surgery for other reasons, such as benign prostatic hyperplasia (a condition in which an overgrowth of prostate tissue occurs). Also called stage A1 prostate cancer.

stage I skin cancer      The tumor is no larger than 2 centimeters.

stage I testicular cancer      Stage I is divided into stage IA, stage IB, and stage IS, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IA, cancer is in the testicle and epididymis and may have spread to the inner layer of the membrane surrounding the testicle; all tumor marker levels are normal. In stage IB, the cancer is in the testicle and the epididymis and has spread to the blood or lymph vessels in the testicle; or has spread to the outer layer of the membrane surrounding the testicle; or is in the spermatic cord or the scrotum and may be in the blood or lymph vessels of the testicle; all tumor marker levels are normal. In stage IS, cancer is found anywhere within the testicle, spermatic cord, or the scrotum and either all tumor marker levels are slightly above normal; or one or more tumor marker levels are moderately above normal or high. 

stage I Wilms' tumor      Cancer that is found in the kidney only and can be completely removed by surgery.

stage IA soft tissue sarcoma      Cancer in which the cells look very much like normal cells. The cancer is smaller than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IB soft tissue sarcoma      Cancer in which the cells look somewhat different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage II adrenocortical cancer      Cancer that is larger than 5 centimeters (about 2 inches) and has not spread into tissues around the adrenal gland.

stage II adult Hodgkin's lymphoma      Stage II is divided into stage II and stage IIE. In stage II, cancer is found in two or more lymph node groups on the same side of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen). In stage IIE, cancer is found in one area or organ other than the lymph nodes and in the lymph nodes near that area or organ, and may have spread to other lymph node groups on the same side of the diaphragm.

stage II adult non-Hodgkin's lymphoma      Stage II is divided into stage II and stage IIE. In stage II, cancer is found in two or more lymph node areas on the same side of the diaphragm. In stage IIE, cancer is found in an organ or tissue other than the lymph nodes and may have spread to one or more lymph nodes on the same side of the diaphragm. 

stage II adult primary liver cancer      One of the following is found: (1) one tumor, which is no larger than 2 centimeters and has spread into nearby blood vessels; or (2) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver; or (3) one tumor, which is larger than 2 centimeters. 

stage II anal cancer      Cancer that has spread beyond the top layer of anal tissue and is larger than 2 centimeters (about 1 inch) but has not spread to nearby organs or lymph nodes.

stage II bladder cancer      Cancer has spread to either the inner layer or outer layer of the muscle wall of the bladder.

stage II breast cancer      Stage II is divided into stage IIA and stage IIB based on tumor size and whether it has spread to the axillary lymph nodes (the lymph nodes under the arm). In stage IIA, the cancer is either no larger than 2 centimeters and has spread to the axillary lymph nodes, or between 2 and 5 centimeters but has not spread to the axillary lymph nodes. In stage IIB, the cancer is either between 2 and 5 centimeters and has spread to the axillary lymph nodes, or larger than 5 centimeters but has not spread to the axillary lymph nodes.

stage II cancer of the uterus      Cancer that has spread to the cervix.

stage II cancer of the vulva      Cancer that is found in the vulva, the space between the opening of the rectum and the vagina (perineum), or both. The tumor is larger than 2 centimeters (larger than 1 inch).

stage II cervical cancer      Cancer has spread beyond the cervix but not to the pelvic wall (the tissues that line the part of the body between the hips). Stage II is divided into stages IIA and IIB, based on how far the cancer has spread. In stage IIA, cancer has spread to the upper two thirds of the vagina but not to tissues around the uterus. In stage IIB, cancer has spread to the upper two thirds of the vagina and to the tissues around the uterus.

stage II childhood non-Hodgkin's lymphoma      Cancer is found (1) in only one area and in the lymph nodes around it; or (2) in two or more areas or lymph nodes on one side of the diaphragm (the thin muscle under the lungs that divides the chest and abdominal cavity and helps with breathing); or (3) to have started in the stomach or intestines and has been completely removed by surgery, and lymph nodes in the area may or may not contain cancer. 

stage II chronic lymphocytic leukemia      There are too many lymphocytes in the blood, the liver or spleen is larger than normal, and the lymph nodes may be larger than normal.

stage II colorectal cancer      Cancer has spread outside the colon and/or rectum to nearby tissue, but it has not gone into the lymph nodes. Also called Dukes' B colorectal cancer.

stage II cutaneous T-cell lymphoma      Stage II cutaneous T-cell lymphoma may be either of the following: (1) stage IIA, in which the skin has red, dry, scaly patches but no tumors, and lymph nodes are enlarged but do not contain cancer cells; (2) stage IIB, in which tumors are found on the skin, and lymph nodes are enlarged but do not contain cancer cells.

stage II endometrial cancer      Cancer has spread from the uterus to the cervix, but not beyond the cervix. Stage II is divided into stages IIA and IIB, based on how far the disease has spread into the cervix.

stage II esophageal cancer      Stage II is divided into stage IIA and stage IIB, depending on where the cancer has spread. In stage IIA, cancer has spread to the layer of esophageal muscle or to the outer wall of the esophagus. In stage IIB, cancer may have spread to any of the first three layers of the esophagus and to nearby lymph nodes.

stage II gastric cancer      Cancer has spread (1) completely through the mucosal (innermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor, or (2) to the muscularis (middle) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor, or (3) to the serosal (outermost) layer of the stomach wall but not to lymph nodes or other organs.

stage II hypopharynx cancer      Cancer that involves more than one area of the hypopharynx or is between 2 and 4 centimeters (between 0.75 and 1.5 inches).

stage II kidney cancer      Tumor that is larger than 7 centimeters (2.75 inches).

stage II laryngeal cancer      Cancer that is found in the larynx only and has not spread to lymph nodes in the area or to other parts of the body. The exact definition of stage II depends on whether the cancer started in the supraglottis (cancer is in more than one area of the supraglottis, but the vocal cords can move normally); the glottis (cancer has spread to the supraglottis, the subglottis, or both, and the vocal cords may not be able to move normally); or the subglottis (cancer has spread to the vocal cords, which may not be able to move normally).

stage II lip and oral cavity cancer      Cancer that is larger than 2 centimeters (about 1 inch) but smaller than 4 centimeters (about 2 inches) and has not spread to lymph nodes in the area.

stage II melanoma      Stage II is divided into stages IIA, IIB, and IIC. In stage IIA, the tumor is either 1 to 2 millimeters thick, with ulceration; or 2 to 4 millimeters thick, with no ulceration. In stage IIB, the tumor is either 2 to 4 millimeters thick, with ulceration; or more than 4 millimeters thick, with no ulceration. In stage IIC, the tumor is more than 4 millimeters thick, with ulceration.

stage II mesothelioma      Cancer that has spread beyond the lining of the chest to lymph nodes in the chest.

stage II multiple myeloma      Cancer in which a moderate number of cancer cells have spread throughout the body.

stage II nasopharyngeal cancer      Stage II is divided into stage IIA and stage IIB. In stage IIA, cancer has spread from the nasopharynx (the upper part of the throat behind the nose) to the oropharynx (the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils), and/or to the nasal cavity. In stage IIB, cancer is found in the nasopharynx and has spread to lymph nodes on one side of the neck, or has spread to the area surrounding the nasopharynx and may have spread to lymph nodes on one side of the neck.

stage II non-small cell lung cancer      Cancer has spread to nearby lymph nodes or to the chest wall, the diaphragm, the mediastinal pleura (the thin membrane that covers the outside of the lungs in the area near the heart), or the parietal pericardium (the outer layer of tissue that surrounds the heart). Stage II is divided into stage IIA and stage IIB based on the size of the tumor and whether it has spread to the lymph nodes. 

stage II oropharynx cancer      Tumor that is between 2 and 4 centimeters (0.75 and 1.5 inches) and is confined to the oropharynx.

stage II ovarian cancer      Cancer is found in one or both ovaries and has spread into other areas of the pelvis. Stage II is divided into stage IIA, stage IIB, and stage IIC. In stage IIA, cancer has spread to the uterus and/or the fallopian tubes. In stage IIB, cancer has spread to other tissues within the pelvis. In stage IIC, cancer has spread to the uterus and/or fallopian tubes and/or other tissue within the pelvis and cancer cells are found in fluid from the peritoneal cavity (the body cavity that contains most of the organs in the abdomen). 

stage II pancreatic cancer      Stage II is divided into stage IIA and stage IIB based on where the cancer has spread. In stage IIA, cancer has spread to nearby tissues and organs but has not spread to nearby lymph nodes. In stage IIB, cancer has spread to nearby lymph nodes and may have spread to nearby tissues and organs.

stage II prostate cancer      Cancer is more advanced than in stage I, but has not spread outside the prostate. Also called stage A2, stage B1, or stage B2 prostate cancer.

stage II skin cancer      The tumor is larger than 2 centimeters.

stage II testicular cancer      Stage II is divided into stage IIA, stage IIB, and stage IIC, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IIA, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and has spread to up to 5 lymph nodes in the abdomen (none larger than 2 centimeters). In stage IIB, the cancer is anywhere within the testicle, spermatic cord, or scrotum; has spread to up to 5 lymph nodes in the abdomen (at least one of the lymph nodes is larger than 2 centimeters, but none is larger than 5 centimeters) or has spread to more than 5 lymph nodes (the lymph nodes are not larger than 5 centimeters). In stage IIC, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and has spread to a lymph node in the abdomen that is larger than 5 centimeters. All tumor marker levels are normal or slightly above normal.

stage II Wilms' tumor      Cancer has spread to tissue near the kidney, to blood vessels, or to the renal sinus (a part of the kidney through which blood and fluid enter and exit). The cancer can be completely removed by surgery.

stage IIA soft tissue sarcoma      The cancer cells look somewhat different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IIB melanoma      Melanoma in which the tumor is more than 4 millimeters thick. It has spread through the lower part of the inner layer of skin (dermis) and into subcutaneous (under the skin) tissue, but not to nearby lymph nodes.

stage IIB soft tissue sarcoma      The cancer cells look very different from normal cells. The cancer is smaller than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IIC soft tissue sarcoma      The cancer cells look very different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage III adrenocortical cancer      The cancer has spread into tissues around the adrenal gland or has spread to the lymph nodes around the adrenal gland.

stage III adult Hodgkin's lymphoma      Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIS+E. In stage III, cancer is found in lymph node groups on both sides of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen). In stage IIIE, cancer is found in lymph node groups on both sides of the diaphragm and in a nearby area or organ other than the lymph nodes. In stage IIIS, cancer is found in lymph node groups on both sides of the diaphragm and in the spleen. In stage IIIE+S, cancer is found in lymph node groups on both sides of the diaphragm, in a nearby area or organ, and in the spleen. Stage III is also divided into stage III(1) and stage III(2). In stage III(1), cancer is limited to the upper abdomen above the renal vein. In stage III(2), cancer is found in lymph nodes in the pelvis and/or near the heart.

stage III adult non-Hodgkin's lymphoma      Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIS+E. In stage III, cancer is found in lymph node areas on both sides of the diaphragm. In stage IIIE, cancer is found in lymph node areas on both sides of the diaphragm and in a nearby organ or tissue other than the lymph nodes. In stage IIIS, cancer is found in lymph node areas on both sides of the diaphragm and in the spleen. In stage IIIS+E, cancer is found in lymph node areas on both sides of the diaphragm, in a nearby organ or tissue, and in the spleen.

stage III anal cancer      Stage III anal cancer is divided into stage IIIA and IIIB. Stage IIIA anal cancer has spread to the lymph nodes around the rectum or to nearby organs such as the vagina or bladder. Stager IIIB cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum.

stage III bladder cancer      Cancer has spread from the bladder to the fatty layer of tissue surrounding it, and may have spread to the reproductive organs (prostate, uterus, vagina). 

stage III breast cancer      Stage III is divided into stages IIIA and IIIB. In stage IIIA breast cancer, the cancer (1) is smaller than 5 centimeters (2 inches) and has spread to the lymph nodes in the armpit, which have grown into each other or into other structures and are attached to them; or (2) is larger than 5 centimeters and has spread to the lymph nodes in the armpit. In stage IIIB breast cancer, the cancer (1) has spread to tissues near the breast (skin, chest wall, including the ribs and the muscles in the chest); or (2) has spread to lymph nodes inside the chest wall along the breast bone.

stage III cancer of the uterus      Cancer cells have spread outside the uterus to the vagina and/or lymph nodes in the pelvis but have not spread outside the pelvis.

stage III cancer of the vulva      Cancer is found in the vulva, perineum, or both. The cancer has also spread to nearby tissues such as the lower part of the urethra (the tube through which urine passes), the vagina, and the anus (the opening of the rectum); to nearby lymph nodes; or both.

stage III cervical cancer      Cancer has spread to the lower third of the vagina and may have spread to the pelvic wall (the tissues that line the part of the body between the hips), and nearby lymph nodes. Stage III is divided into stages IIIA and IIIB, based on now far the cancer has spread. In stage IIIA, cancer has spread to the lower third of the vagina but not to the pelvic wall. In stage IIIB, cancer has spread to the pelvic wall and/or the tumor has become large enough to block the ureters (the tubes that connect the kidneys to the bladder). This blockage can cause the kidneys to enlarge or stop working. Cancer may also have spread to lymph nodes in the pelvis.

stage III childhood non-Hodgkin's lymphoma      Cancer is found (1) in areas or lymph nodes on both sides of the diaphragm (the thin muscle under the lungs that divides the chest and abdominal cavity and helps with breathing); or (2) to have started in the chest; or (3) in more than one place in the abdomen; or (4) in the area around the spine.

stage III chronic lymphocytic leukemia      There are too many lymphocytes in the blood and there are too few red blood cells. The lymph nodes, liver, or spleen may be larger than normal.

stage III colorectal cancer      Tumor cells have spread to organs and lymph nodes near the colon/rectum. Also called Dukes C colorectal cancer.

stage III cutaneous T-cell lymphoma      Nearly all of the skin is red, dry, and scaly; lymph nodes are either normal or enlarged but do not contain cancer cells.

stage III endometrial cancer      Cancer has spread beyond the uterus and cervix, but has not spread beyond the pelvis. Stage III is divided into stages IIIA, IIIB, and IIIC, based on whether cancer has spread to the connective tissue holding the uterus in place, the ovaries, fallopian tubes, vagina, and lymph nodes in the pelvis.

stage III esophageal cancer      Cancer has spread to the outer wall of the esophagus and may have spread to tissues or lymph nodes near the esophagus.

stage III gastric cancer      Stage III is divided into stage IIIA and stage IIIB depending on where the cancer has spread. In stage IIIA, cancer has spread to (1) the muscularis (middle) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor, or (2) the serosal (outermost) layer of the stomach wall and is found in 1 to 6 lymph nodes near the tumor, or (3) to organs next to the stomach but not to lymph nodes or other parts of the body. In stage IIIB, cancer has spread to the serosal (outermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor.

stage III hypopharynx cancer      The tumor is larger than 4 centimeters (about 1.5 inches) in size, has spread to a single lymph node on the same side of the neck, or both.

stage III kidney cancer      Cancer has spread to a single nearby lymph node, and/or the layer of tissue around the kidney, and/or the main blood vessels in the kidney, and/or an adrenal gland. Also called stage III renal cell cancer.

stage III laryngeal cancer      The cancer has not spread outside of the larynx, but the vocal cords cannot move normally, or the cancer has spread to tissues next to the larynx; or the cancer has spread to one lymph node on the same side of the neck as the original tumor, and the lymph node measures no larger than 3 centimeters (just over 1 inch).

stage III lip and oral cavity cancer      The cancer is larger than 4 centimeters (about 2 inches); or the cancer is any size but has spread to only one lymph node on the same side of the neck as the cancer. The lymph node that contains cancer is no larger than 3 centimeters (just over one inch).

stage III melanoma      The tumor may be of any thickness, with or without ulceration, and may have spread to 1 or more nearby lymph nodes. Stage III is divided into stages IIIA, IIIB, and IIIC. In stage IIIA, the cancer may have spread to as many as 3 nearby lymph nodes, but can be seen only with a microscope. In stage IIIB, the cancer has spread to as many as 3 lymph nodes and may not be visible without a microscope, or has satellite tumors (additional tumor growths within 1 inch of the original tumor) and has not spread to lymph nodes. In stage IIIC, the cancer either has spread to as many as 4 or more lymph nodes and can be seen without a microscope, or has lymph nodes that may not be moveable, or has satellite tumors and may have spread to lymph nodes. 

stage III mesothelioma      Cancer has spread into the lung, chest wall, diaphragm (the muscle between the chest and the abdomen), the sac surrounding the heart, or the ribs. It may also have spread to other organs or tissues in the chest.

stage III multiple myeloma      A relatively large number of cancer cells have spread throughout the body. There may be one or more of the following: 1) a decrease in the number of red blood cells, causing anemia; 2) the amount of calcium in the blood is very high, because the bones are being damaged; 3) more than three bone tumors (plasmacytomas) are found; or 4) high levels of M protein are found in the blood or urine.

stage III nasopharyngeal cancer      Cancer is found in the nasopharynx (the upper part of the throat behind the nose) and has spread to lymph nodes on both sides of the neck; and/or cancer has spread to the oropharynx (the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils) and/or the nasal cavity and to lymph nodes on both sides of the neck; and/or cancer has spread to nearby bones or sinuses, with or without spreading to lymph nodes on one or both sides of the neck. 

stage III non-small cell lung cancer      Cancer has spread to structures near the lung; to the lymph nodes in the area that separates the two lungs (mediastinum); or to the lymph nodes on the other side of the chest or in the lower neck. Stage III is further divided into stage IIIA (usually can be resected which is sometimes treated with surgery) and stage IIIB (usually cannot be resected which is rarely treated with surgery).

stage III oropharynx cancer      The tumor is larger than 4 centimeters (about 1.5 inches) in size and may involve a single lymph node on the same side of the neck.

stage III ovarian cancer      Cancer is found in one or both ovaries and has spread to other parts of the abdomen. Stage III is divided into stage IIIA, stage IIIB, and stage IIIC. In stage IIIA, the tumor is found in the pelvis only, but cancer cells have spread to the surface of the peritoneum. In stage IIIB, cancer has spread to the peritoneum but is not larger than 2 centimeters in diameter. In stage IIIC, cancer has spread to the peritoneum and is larger than 2 centimeters in diameter and/or has spread to lymph nodes in the abdomen. Cancer that has spread to the surface of the liver is also considered stage III disease.

stage III pancreatic cancer      Cancer has spread to the major blood vessels near the pancreas, and may have spread to nearby lymph nodes.

stage III prostate cancer      Cancer has spread beyond the outer layer of the prostate to nearby tissues and may be found in the seminal vesicles (glands that help produce semen). Also called stage C prostate cancer.

stage III skin cancer      Cancer has spread below the skin to cartilage, muscle, or bone and/or to nearby lymph nodes, but not to other parts of the body. 

stage III soft tissue sarcoma      The cancer cells look very different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) but has not spread to lymph nodes or other parts of the body.

stage III testicular cancer      Stage III is divided into stage IIIA, stage IIIB, and stage IIIC, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IIIA, the cancer is anywhere within the testicle, spermatic cord, or scrotum; may have spread to one or more lymph nodes in the abdomen; and has spread to distant lymph nodes or to the lungs. In stage IIIB, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and may have spread to one or more nearby or distant lymph nodes or to the lungs. In stage IIIC, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and may have spread to one or more nearby or distant lymph nodes or to the lungs or anywhere else in the body. The level of one or more tumor markers may range from normal to very high. 

stage III Wilms' tumor      Cancer has spread to tissues near the kidney and cannot be completely removed by surgery. The cancer may have spread to blood vessels or organs near the kidney or throughout the abdomen. The cancer may also have spread to lymph nodes near the kidney.

stage IIIA adult primary liver cancer      Stage III is divided into stage IIIA and IIIB. In stage IIIA, one of the following is found: (1) one tumor, which is larger than 2 centimeters and has spread to nearby blood vessels; or (2) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver and have spread to nearby blood vessels; or (3) more than one tumor, at least one of which is larger than 2 centimeters, and all are in just one lobe of the liver and may have spread to nearby blood vessels. 

stage IIIA anal cancer      Cancer has spread to the lymph nodes around the rectum or to nearby organs such as the vagina or bladder.

stage IIIA breast cancer      The tumor is either smaller than 5 centimeters and has spread to the axillary lymph nodes (the lymph nodes under the arm), and the lymph nodes are attached to each other or to other structures, or the tumor is larger than 5 centimeters and has spread to the axillary lymph nodes, and the lymph nodes may be attached to each other or to other structures.

stage IIIB adult primary liver cancer      Stage III is divided into stage IIIA and IIIB. In stage IIIB, the cancer has spread to nearby lymph nodes and one of the following is found: (1) one tumor, which may be larger than 2 centimeters; or (2) one tumor, which may be larger than 2 centimeters and has spread to nearby blood vessels; or (3) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver; or (4) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver and have spread to nearby blood vessels; or (5) more than one tumor, at least one of which is larger than 2 centimeters, and all are in just one lobe of the liver and may have spread to nearby blood vessels.

stage IIIB anal cancer      Cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum.

stage IIIB breast cancer      The tumor may be any size, has spread to the tissues near the breast (the skin or chest wall, including the ribs and muscles in the chest), and may have spread to lymph nodes within the breast or under the arm.

stage IIIC breast cancer      Cancer has spread to lymph nodes beneath the collar bone and near the neck, and may have spread to tissues near the breast (the skin or chest wall, including the ribs and muscles in the chest) and to lymph nodes within the breast or under the arm.

stage IV adrenocortical cancer      The cancer has spread to tissues or organs in the area and to lymph nodes around the adrenal cortex, or the cancer has spread to other parts of the body.

stage IV adult Hodgkin's lymphoma      The cancer is found in at least one organ other than the lymph nodes and may be in the lymph nodes near the organ(s); or the cancer is found in one organ other than the lymph nodes and has spread to lymph nodes far away from the organ. 

stage IV adult non-Hodgkin's lymphoma      The cancer either (1) is found in at least one organ or tissue other than the lymph nodes and may be in nearby lymph nodes; or (2) has spread to one organ other than the lymph nodes and has spread to lymph nodes far away from that organ.

stage IV adult primary liver cancer      Stage IV is divided into stage IVA and IVB. In stage IVA, there is more than one tumor, which may have spread to nearby lymph nodes, and the tumors (1) are in both lobes of the liver; or (2) are affecting a major branch of blood vessels in the liver; or (3) have spread to nearby organs (besides the gallbladder); or (4) have broken through the lining of the peritoneal cavity. In stage IVB, the cancer has spread beyond the liver to other places in the body. The tumors may be of any size and may have also spread to nearby blood vessels and lymph nodes.

stage IV anal cancer      Cancer has spread to distant lymph nodes within the abdomen or to organs in other parts of the body.

stage IV bladder cancer      Cancer has spread from the bladder to the wall of the abdomen or pelvis. Cancer may have spread to one or more lymph nodes or to other parts of the body.

stage IV breast cancer      Cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain; or tumor has spread locally to the skin and lymph nodes inside the neck, near the collarbone.

stage IV cancer of the uterus      Cancer cells have spread to the lining of the bladder or rectum or to distant parts of the body.

stage IV cancer of the vulva      Cancer has spread beyond the urethra, vagina, and anus into the lining of the bladder (the sac that holds urine) and the bowel (intestine); or it may have spread to the lymph nodes in the pelvis or to other parts of the body.

stage IV cervical cancer      Cancer has spread to the bladder, rectum, or other parts of the body. Stage IV is divided into stages IVA and IVB. In stage IVA, cancer has spread to the bladder or rectal wall and may have spread to lymph nodes in the pelvis. In stage IVB, cancer has spread beyond the pelvis and pelvic lymph nodes to other places in the body, such as the abdomen, liver, intestinal tract, or lungs.

stage IV childhood non-Hodgkin's lymphoma      Cancer is found in the bone marrow, brain, or spinal cord. Cancer may also be found in other parts of the body.

stage IV chronic lymphocytic leukemia      There are too many lymphocytes in the blood and too few platelets. The lymph nodes, liver, or spleen may be larger than normal and there may be too few red blood cells.

stage IV colorectal cancer      Cancer may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs. Also called Dukes' D colorectal cancer.

stage IV cutaneous T-cell lymphoma      Stage IV cutaneous T-cell lymphoma may be either of the following: in stage IVA cancer, the skin is red, dry, and scaly, and the lymph nodes contain cancer cells; in stage IVB cancer, the skin is red, dry and scaly, cancer cells may be found in lymph nodes, and cancer has spread to other organs in the body.

stage IV endometrial cancer      Cancer has spread beyond the pelvis. Stage IV is divided into stages IVA and IVB, based on whether cancer has spread to the lining of the bladder (the sac that holds urine), to the bowel, or to lymph nodes or other parts of the body beyond the pelvis.

stage IV esophageal cancer      Stage IV esophageal cancer is divided into stage IVA and stage IVB, depending on where the cancer has spread. In stage IVA, cancer has spread to nearby or distant lymph nodes. In stage IVB, cancer has spread to distant lymph nodes and/or organs in other parts of the body.

stage IV gastric cancer      Cancer has spread (1) to organs next to the stomach and to at least one lymph node, or (2) to more than 15 lymph nodes, or (3) to other parts of the body.

stage IV hypopharynx cancer      The tumor has spread to nearby tissues and lymph nodes of the neck and may have spread to other parts of the body.

stage IV kidney cancer      Cancer has spread beyond the kidney to 1 or more nearby lymph nodes and/or to other organs. Also called stage IV renal cell cancer.

stage IV laryngeal cancer      The cancer has spread to tissues around the larynx, such as the pharynx or the tissues in the neck. The lymph nodes in the area may contain cancer; the cancer has spread to more than one lymph node on the same side of the neck as the cancer, to lymph nodes on one or both sides of the neck, or to any lymph node that measures more than 6 centimeters (over 2 inches); or the cancer has spread to other parts of the body.

stage IV lip and oral cavity cancer      The cancer has spread to tissues around the lip and oral cavity (the lymph nodes in the area may contain cancer); the cancer is any size and has spread to more than one lymph node on the same side of the neck as the cancer, to lymph nodes on one or both sides of the neck, or to any lymph node that is larger than 6 centimeters (larger than 2 inches); or the cancer has spread to other parts of the body.

stage IV melanoma      The tumor has spread to other organs or to lymph nodes far away from the original tumor.

stage IV mesothelioma      Cancer has spread to distant organs or tissues.

stage IV nasopharyngeal cancer      Stage IV is divided into stage IVA, stage IVB, and stage IVC. In stage IVA, cancer has spread to other areas in the head and may have spread to lymph nodes on one or both sides of the neck, and the involved lymph nodes are smaller than 6 centimeters. In stage IVB, cancer has spread to lymph nodes above the collarbone and/or the involved lymph nodes are larger than 6 centimeters. In stage IVC, cancer has spread beyond nearby lymph nodes to other parts of the body.

stage IV non-small cell lung cancer      Cancer has spread to other parts of the body or to another lobe of the lungs.

stage IV oropharynx cancer      The tumor has spread to the hard palate, tongue, or larynx, to nearby lymph nodes, and may have spread to other parts of the body.

stage IV ovarian cancer      Cancer is found in one or both ovaries and has metastasized (spread) beyond the abdomen to other parts of the body. Cancer that is found in tissues of the liver is considered stage IV disease.

stage IV pancreatic cancer      Cancer may be of any size and has spread to distant organs, such as the liver, lung, and peritoneal cavity (the body cavity that contains most of the organs in the abdomen), and may have also spread to organs and tissues near the pancreas or to lymph nodes.

stage IV prostate cancer      Cancer has metastasized (spread) to lymph nodes near or far from the prostate, or to other parts of the body, such as the bladder, rectum, bones, liver, or lungs. Metastatic prostate cancer often spreads to the bones. Also called stage D1 or stage D2 prostate cancer.

stage IV skin cancer      Cancer has spread to other parts of the body.

stage IV soft tissue sarcoma      The cancer has spread to lymph nodes in the area or other parts of the body (such as the lungs, head, or neck).

stage IV Wilms' tumor      Cancer has spread to organs further away from the kidney (such as the lungs, liver, bone, and brain).

stage IVA pancreatic cancer      Cancer has spread to organs that are near the pancreas (such as the stomach, spleen, or colon) but has not spread to distant organs (such as the liver or lungs). 

stage IVB pancreatic cancer      Cancer of the pancreas in which the cancer has spread to distant organs (such as the liver or lungs).

stage V Wilms' tumor      Cancer cells are found in both kidneys.

staging  (STAY-jing)    Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

standard of care      In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with the standard of care. Also called standard therapy or best practice.

standard therapy      In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called standard of care or best practice. 

stem cell transplantation      A method of replacing immature blood-forming cells that were destroyed by cancer treatment. The stem cells are given to the person after treatment to help the bone marrow recover and continue producing healthy blood cells.

stent      A device placed in a body structure (such as a blood vessel or the gastrointestinal tract) to provide support and keep the structure open.

stereotactic biopsy  (STAIR-ee-o-TAK-tik BY-op-see)    A biopsy procedure that uses a computer and a three-dimensional scanning device to find a tumor site and guide the removal of tissue for examination under a microscope.

stereotactic body radiation therapy      A radiation therapy technique that uses special equipment to position the patient and precisely deliver a large radiation dose to a tumor and not to normal tissue.

stereotactic external-beam radiation      A radiation therapy technique for brain tumors that uses a rigid head frame attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic radiation therapy, stereotactic radiosurgery, and stereotaxic radiosurgery.

stereotactic radiation therapy  (STAIR-ee-o-TAK-tik ray-dee-AY-shun)    A radiation therapy technique for brain tumors that uses a rigid head frame that is attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic external-beam radiation, stereotactic radiosurgery, and stereotaxic radiosurgery. 

stereotactic radiosurgery  (STAIR-ee-o-TAK-tik...)    A radiation therapy technique for brain tumors that uses a rigid head frame that is attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic external-beam radiation, stereotactic radiation therapy, and stereotaxic radiosurgery. 

stomatitis      Inflammation or irritation of the mucous membranes in the mouth.

subjective improvement      An improvement that is reported by the patient, but cannot be measured by the healthcare provider (for example, "I feel better").

survival rate      The percentage of people in a study or treatment group who are alive for a given period of time after diagnosis. This is commonly expressed as 5-year survival.

syncope     A temporary suspension of consciousness due to generalized cerebral ischemia; a faint or swoon.

systemic  (sis-TEM-ik)    Affecting the entire body.

systemic chemotherapy      Treatment with anticancer drugs that travel through the bloodstream, reaching and affecting cells all over the body.

systemic disease      Disease that affects the whole body.

therapy      Treatment.

thrombocyte  (THROM-bo-site)    A blood cell that helps prevent bleeding by causing blood clots to form. Also called a platelet.

thrombocytopenia, thrombopenia      A decrease in the number of platelets in the blood that may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.

thrombosis  (throm-BOW-sis)    The formation or presence of a blood clot inside a blood vessel.

time to progression      A measure of time after a disease is diagnosed (or treated) until the disease starts to get worse.

TNM staging system      A system for describing the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).

total parenteral nutrition      TPN. Intravenous (into a vein) feeding that provides necessary nutrients when a person is unable to eat normally.

total-body irradiation      Radiation therapy to the entire body. Usually followed by bone marrow or peripheral stem cell transplantation.

toxic      Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

transformation      The change that a normal cell undergoes as it becomes malignant.

transfusion  (trans-FYOO-zhun)    The infusion of components of blood or whole blood into the bloodstream. The blood may be donated from another person, or it may have been taken from the person earlier and stored until needed.

transrectal ultrasound  (TRANS-REK-tal)    TRUS. A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. TRUS is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called endorectal ultrasound. 

transurethral biopsy      A procedure in which a sample of tissue is removed from the prostate for examination under a microscope. A thin, lighted tube is inserted through the urethra into the prostate, and a small piece of tissue is removed with a cutting loop.

transurethral needle ablation      A procedure that is used to treat benign prostatic hypertrophy (BPH). A small probe that gives off low-level radiofrequency energy is inserted through the urethra into the prostate. The energy from the probe heats and destroys the abnormal prostate tissue without damaging the urethra. Also called transurethral radiofrequency ablation.

transurethral resection  (TRANZ-yoo-REE-thral ree-SEK-shun)    Surgery performed with a special instrument inserted through the urethra. Also called TUR.

transurethral resection of the prostate  (TRANZ-yoo-REE-thral ree-SEK-shun)    Surgical procedure to remove tissue from the prostate using an instrument inserted through the urethra. Also called TURP.

treatment field      In radiation therapy, the place on the body where the radiation beam is aimed.

tumor  (TOO-mer)    A mass of excess tissue that results from abnormal cell division. Tumors perform no useful body function. They may be benign (not cancerous) or malignant (cancerous).

tumor board review      A treatment planning approach in which a number of doctors who are experts in different specialties (disciplines) review and discuss the medical condition and treatment options of a patient. In cancer treatment, a tumor board review may include that of a medical oncologist (who provides cancer treatment with drugs), a surgical oncologist (who provides cancer treatment with surgery), and a radiation oncologist (who provides cancer treatment with radiation). Also called a multidisciplinary opinion.

tumor burden      Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor load.

tumor debulking      Surgically removing as much of the tumor as possible.

tumor load      Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor burden.

tumor marker      A substance sometimes found in the blood, other body fluids, or tissues. A high level of tumor marker may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (prostate cancer). Also called biomarker.

tumor necrosis factor  (TOO-mer ne-KRO-sis)    A type of biological response modifier (a substance that can improve the body's natural response to disease). Three types of tumor necrosis factor have been identified: alpha, beta, and gamma. Tumor necrosis factor seems to play a role in the breakdown of cancer cells.

tumor suppressor gene  (TOO-mer)    Genes in the body that can suppress or block the development of cancer.

tumor-specific antigen      A protein or other molecule that is unique to cancer cells or is much more abundant in them. These molecules are usually found in the plasma (outer) membrane, and they are thought to be potential targets for immunotherapy or other types of anticancer treatment.

uncontrolled study      A clinical study that lacks a comparison (i.e., a control) group.

undifferentiated      A term used to describe cells or tissues that do not have specialized ("mature") structures or functions. Undifferentiated cancer cells often grow and spread quickly.

unresectable      Unable to be removed with surgery.

unresectable gallbladder cancer      Cancer that has spread to the tissues around the gallbladder (such as the liver, stomach, pancreas, intestine, or lymph nodes in the area) and cannot be surgically removed.

vaccine therapy      A type of treatment that uses a substance or group of substances to stimulate the immune system to destroy a tumor or infectious microorganisms such as bacteria or viruses.

valerian      Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called garden valerian, Indian valerian, Pacific valerian, Mexican valerian, garden heliotrope, and Valerianae radix. 

WBC      White blood cell. Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.

wild clover      Trifolium pratense. A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called red clover and purple clover.

Wilms' tumor      A kidney cancer that usually occurs in children younger than 5 years old.

Wobe-Mugos E      A mixture made from an extract of the calf thymus gland and enzymes (proteins that speed up chemical reactions in the body) from the papaya plant, the pancreas of cows, and the pancreas of pigs. It has been used in Europe as a treatment for a variety of cancers and for herpes virus infections.

x-ray therapy      The use of high-energy radiation from x-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or from materials called radioisotopes. Radioisotopes produce radiation and can be placed in or near the tumor or in the area near cancer cells. This type of radiation treatment is called internal radiation therapy, implant radiation, interstitial radiation, or brachytherapy. Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. X-ray therapy is also called radiation therapy, radiotherapy, and irradiation. 

xenograft      The cells of one species transplanted to another species.

yttrium  (IH-tree-um)    A rare elemental metal. A radioactive form of yttrium is used in radiation therapy and some types of immunotherapy.