| These tests can determine which drug or drug combination
will or will not work for your cancer
What are these tests?
These tests or "assays" can be performed on pieces of tumors
taken directly from patients. They provide information on the likelihood
that different types of chemotherapy will provide clinical benefit to
What is the advantage to using these assays?
These assays are used to identify the best forms of chemotherapy for
cancer patients on an individual basis. If an assay is not performed,
chemo is chosen on the basis of a "one size fits all" approach.
Scientists and doctors who support the use of the assays believe that
by using the test to help identify the best type of treatment, toxic and
ineffectual chemotherapy can be avoided.
What kind of material is used?
The tests can be performed on all solid tumors (biopsies or larger specimens)
or cancer containing fluids from blood, bone marrow, or other parts of
the human body.
Is there a name for these tests?
Yes, they go by a number of names including: Human Tumor Assays (the
term used by Medicare) Chemosensitivity and Resistance Assays (CSRA's),
and Human Tumor Live Cell Assays (HTLCA's).
Is there scientific proof to support the validity of these tests?
Yes, there is scientific literature documenting the correlation between
test results and treatment results. The tests have been shown to identify
relatively "good" and relatively "bad" forms of chemotherapy
for individual patients. Patients treated with drugs active in the assays
have, on average, a 7-fold greater chance of benefiting from treatment
with drugs showing good results in the assays compared with treatment
with drugs showing poor results in the assays. Benefits from treatment
can mean both a response (temporary decrease in size of cancer) and lengthened
Are these tests widely accepted and used by most hospitals?
No. You must request these tests from your oncologist and/or directly
contact a lab that performs these assays. The use of these assays has
been opposed by some large insurance companies and by the American Society
of Clinical Oncology, based on the fact that there have been no prospective,
randomized trials to "prove" that assay-directed chemotherapy
provides superior results, compared to one-size-fits-all chemotherapy.
In other words, while there are studies that demonstrate that these assays
can and do provide helpful information to individual patients, there have
not been studies in which one group of patients was treated based on an
assay and another group of patients was treated with a one size fits all
approach and the results of the two randomized groups were compared to
see which did better.
Why haven't these randomized trials been performed?
Prospective, randomized, controlled clinical trials cost millions of
dollars, but the most promising assay technologies are public domain,
non-proprietary technologies. No company will invest that much money for
something that is difficult to patent. In addition, as noted by Dr. Maurie
Markman of the Cleveland Clinic, the trial to prove effectiveness in one
clinical situation would become instantly irrelevant with the introduction
of the first new drug which wasn't available for testing at the time of
Is their any danger in using these tests to help choose a cancer
There is a theoretical risk only in cases where a clearly superior form
chemotherapy has been identified in controlled clinical trials. However,
there are very few situations in cancer treatment where one clearly superior
form of chemotherapy has been identified. One such case might be previously-untreated
testicular cancer, where the combination of cisplatin/etoposide/ bleomycin
on one particular schedule has been shown to be superior to all other
treatments with which it has been compared. But there are almost no other
situations in cancer chemotherapy in which this is true. In virtually
all situations, there are several to many different forms of chemotherapy,
all of which would be expected to have similar probabilities of benefit,
if chosen by random selection and given to an "average" group
How much do these tests cost and are they covered by insurance?
The cost of these tests typically ranges from $1,500 to $4,000. Coverage
for these tests is officially disallowed by most BlueCross/BlueShield
plans (although there are exceptions, such as California Blue Shield,
which does officially provide coverage for testing). Many private insurance
plans (including many managed care plans) do pay for the testing. Medicare
has no national policy, leaving coverage decisions up to the various regional
Medicare contractors (the California Medicare contractor does provide
Is there additional information a patient should know?
It must also be realized that these assays are complex procedures, fraught
with the potential for error and misinterpretation. The results are only
meaningful to the extent that the laboratory in question is experienced
and diligent in its quality assurance practices. A patient interested
in this testing should not hesitate to ask specific questions and to require
specific answers of the laboratories under consideration.
Lastly, it must be realized that the assays only provide information,
and the information is useless if it is not seriously considered by the
treating oncologist in drug selection and treatment planning. Therefore,
if you are interested in using an assay it is important to identify a