Gene test predicts survival for lymphoma patients
Thursday, June 20th 2002, 12:00 am
By: News On 6
BOSTON (AP) _ Cancer researchers have devised a genetic test that can accurately predict the survival chances of patients with some aggressive forms of lymphoma.
The test yielded a genetically based survival index for people with diffuse large-B-cell lymphomas. It is a better predictor than current methods, which consider a patient's age, the stage and spread of the disease, and similar factors, said Dr. Louis Staudt of the National Cancer Institute, who supervised the international study.
But he said both methods might eventually be used in tandem for the best possible prediction.
That could help doctors decide on the best course of treatment. Patients with a bleak outlook, for example, could be given experimental drugs or a bone marrow transplant.
The study was published in Thursday's New England Journal of Medicine.
The technique adds diffuse large-B-cell lymphomas to a growing list of cancers that can be classified and characterized by their genetic makeup, instead of how they affect patients and appear under a microscope. Such genetically classified diseases include breast cancer and some types of leukemia.
``In the future, what's going to be more important is not what a cell looks like, but its genetic expression pattern and the genetic abnormalities that are present in that cell,'' said Dr. Ian Mcgrath, at the International Network for Cancer Research in Brussels, Belgium. ``My guess is that this principle will apply to the vast bulk of tumors.''
Lymphoma is a cancer of the immune system. About 16,000 cases of diffuse large-B-cell lymphoma are diagnosed each year in the United States. Many scientists have begun to view the condition as multiple diseases, since only about 40 percent of patients are cured by chemotherapy. Nearly all the rest die.
The researchers studied tissue samples from 240 patients with diffuse large-B-cell lymphoma. Based on their analysis of about 10,000 genes, they found at least three distinct diseases, with varying chances of survival.
Then, using 17 specific genes, the researchers created a survival-prediction index. Patients who scored in the top half had better than a 70 percent chance of surviving for five years with chemotherapy. The bottom quarter had only a 15 percent chance.
The study also pinpointed several gene-linked biochemical pathways where experimental lymphoma drugs might be aimed.
``This gives us an idea of the particular abnormal machinery of the cancer cells, which gives us ideas of different therapies,'' Staudt said.
This fall, the researchers will begin drug tests on a promising pathway known as NF-kB, he said.