Short-term efficacy of rituximab-CHOP and CHOP regimens on two subtypes of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) can be divided into two subgroups as germinal center B-cell like (GCB) and non-GCB DLBCL, according to the origin of tumor cells. The prognosis of GCB DLBCL is better than that of non-GCB DLBCL after receiving the CHOP regimen on initial therapy. This study was to compare the short-term efficacy of rituximab(R)-CHOP and CHOP regimens on GCB and non-GCB DLBCL, thus to explore the optimal first-line regimen for the initial treatment of DLBCL patients.

In total, eighty-three patients with de novo DLBCL initially treated at Sun Yat-sen University Cancer Center from November 2006 to February 2008 were enrolled. Patients were divided into GCB and non-GCB groups. The short-term efficacy of the CHOP or R-CHOP regimen as the first-line therapy on the two groups was evaluated according to the revised response criteria for lymphoma. Bcl-2 expression and its correlation to the short-term efficacy of the two groups were assessed.

There were 35 cases (42.2%) in the GCB group and 48 cases (57.8%) in the non-GCB group. The total remission rate was 74.3% in the GCB group and 60.4% in the non-GCB group (p = 0.006). There was no significant difference in Bcl-2 expression in the two groups. The remission rate was higher in Bcl-2 positive patients receiving R-CHOP regimen than those receiving CHOP regimen (75.6% vs. 47.8%, p = 0.023). There was no significant difference in the remission rate of Bcl-2 negative patients, regardless of chemotherapy regimen.

The prognosis is better in the GCB group than in the non-GCB group. Addition of rituximab to CHOP could improve the short-term efficacy of Bcl-2 positive patients.