When a person is diagnosed with diffuse large-B-cell lymphoma, doctors use a group of indicators called the International Prognostic Index, or IPI, which includes a person's age, tumor stage and blood markers to decide how to treat the cancer. Those with the highest IPI scores get the most aggressive therapy. However, two people with the same score may still react differently to treatment. One thought has been that a genetic screen may fine-tune the distinction between the most aggressive and least aggressive cancers.

"It makes a big difference in your treatment decisions if you think you have a high chance of success or if you don't," said Ronald Levy, MD, the Robert K. and Helen K. Summy Professor, who led the study. He said if doctors know a patient isn't likely to respond well to standard therapy, the patient may be a candidate for novel therapies undergoing clinical trials.

"New therapies are usually tested in people who have failed the standard therapy," Levy said. "If you know in advance who won't respond well, you can treat them more aggressively or include these patients in trials of the many promising, new targeted therapies."

Over the past five years groups of researchers have used microarrays, which take a snapshot of which genes are active in different tissues, to find large groups of genes that predict a person's survival. These studies have resulted in huge lists of mostly non-overlapping genes. Not only are there too many genes to be screened by most medical labs, the research groups haven't agreed on which genes should be part of those screens.

Levy and his colleagues narrowed the list of potentially informative genes down to the
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Contact: Amy Adams
650-723-3900
Stanford University Medical Center
28-Apr-2004