A New Test Helps Oncologists Make Treatment Decisions for People With Lymphoma


Medically Reviewed On: July 18, 2002

by: Erica Heilman

A new genetic test that has been applied to certain aggressive forms of lymphoma is offering clinicians a clearer picture of patients' chances of survival. It is also joining the ranks of critical new developments in oncology that are pointing the way to more targeted treatments for cancer.

"Not so long ago, no one had any idea what made a cancer cell a cancer cell," says Dr. Ian Magrath, Medical and Scientific Director of the International Network for Cancer Treatment and Research in Brussels. "Now we have, in many cases, rather precise information about the pathways to cancer, and the process has become less mystical."

The new test, developed by Pat Brown of Stanford University and used by researchers at the National Cancer Institute in collaboration with other major centers, offers clinicians a genetically-based survival index for people who have undergone chemotherapy for diffuse large-B-cell lymphomas, the most common type of adult lymphoma.

Below, Dr. Magrath talks about the new genetic test for lymphoma, and its larger implications.

Why is it important to predict a lymphoma patient's chances for survival?
There are many reasons. From the oncologist's perspective, predicting outcome may be important in choosing optimal therapy, or deciding whether the patient is eligible for a particular research study. If, for example, a patient has an excellent chance of survival, and falls into a "low risk" group, then the physician could recommend a standard, well-tolerated therapy. If, however, the patient does not have excellent survival chances (with traditional therapies), and is in a "high risk" group, one might, propose to the patient some form of experimental therapy rather than the standard therapy.

Also, in order to make informed decisions, patients ought to be given some idea of what to expect, both in terms of effectiveness of therapy, and toxic side effects. An elderly patient, for example, with a very low chance of survival, may decide not to receive chemotherapy, or may opt for a less toxic treatment approach, even if other, more toxic therapies may offer a slightly better chance of survival.

What does this new genetic test measure?
The test, which is called DNA microarray, provides a good representation of the gene expression pattern of a tumor and and at the same time, provides a comparative picture of the pattern of gene expression in the tumor cells compared to that in normal cells.

How does it work?
In very broad terms, genetic material (RNA) is extracted from the tumor cells and "translated" into DNA (genes), which is "tagged" with a colored fluorescent material, let's say red. The same extraction process is done in normal cells, and this DNA is tagged with green dye.

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