Washington. An international team of researchers has reclassified the most common type of lymphoma by identifying its genetic subtypes, providing an explanation why some patients with the disease respond to treatment and others don’t and potentially a therapeutic improvement.

A study published on Wednesday in the New England Journal of Medicine has found that the diffuse large B-cell lymphoma (DLBCL) has four prominent genetic subtypes that each share a group of genetic aberrations.

Patients with two of the subtypes, called BN2 and EZB, respond well to treatment, while those with the other two, MCD and N1, do not. The standard treatment for the disease is a combination of chemotherapy drugs plus rituximab, a drug known as a monoclonal antibody.

Previously, researchers classified patients into those with activated B-cell-like (ABC) DLBCL, with about a 40 percent average survival rate, and those with germinal center B-cell-like (GCB) DLBCL, with about a 75 percent average survival rate.

But even in the GCB subgroup, many patients experience disease relapse after treatment. Scientists performed a multi-platform analysis of genomic alterations and gene expression on tumor samples from 574 patients with DLBCL.

They found some of these subtypes can be found in both ABC and GCB subgroups.

“Before, even with our most advanced molecular diagnosis, we would have said all ABC tumors are the ‘bad’ type and they need to be treated aggressively,” said Louis M. Staudt at the National Cancer Institute who led the study.

“Now we can implement this kind of classification and say that even if a patient has the ‘bad’ ABC type, they have the ‘good’ genetic type, BN2. So, there’s a much better chance of chemotherapy curing the disease,” said Staudt. (Xhinua)