November 26 (HealthDay News) -- Gene activity patterns can tell doctors whether people with a certain type of non-Hodgkin lymphoma have a better chance of survival with treatment, according to a new study.

Three different signatures of gene activity, or expression -- a measure of the biological activity of a gene -- have been identified in people with diffuse large B-cell lymphoma (DLBCL). One signature, stromal-2, was linked to poor prognosis.

In studying thousands of genes in DLBCL tumors, the researchers determined that nonmalignant immune and structural cells lying near the tumor cells also have a great effect on how well patients respond to therapy.

"These biological variations are significant in patients treated with the current standard of care," study leader Dr. Louis M. Staudt of the U.S. National Cancer Institute, said in a news release issued by the organization. "Our results provide many fresh ideas about how existing drugs might be utilized to overcome the remaining resistance of some DLBCL tumors to our current therapy."

The findings were published in the Nov. 27 issue of the New England Journal of Medicine.

Diffuse large B-cell lymphoma, an aggressive type of non-Hodgkin lymphoma with several subtypes, makes up 30 percent of all newly diagnosed cases. The standard treatment for DLBCL is a combination five drugs -- cyclophosphamide, hydroxydoxorubicin (doxorubicin, Adriamycin), Oncovin (vincristine), prednisone and rituximab. Known as R-CHOP, this treatment cures up to 60 percent of patients.

Combining the new gene signature model with the International Prognostic Index (IPI), an index to predict survival of DLBCL patients based on factors such as age, stage of the tumor and spread of the cancer, improved how well both models predicted prognosis. According to the researchers, this suggests that clinical factors as well as tumor characteristics each affect the outcomes of DLBCL patients receiving treatment.

SOURCE: U.S. National Cancer Institute, news release, Nov. 26, 2008