Rituximab in combination with CHOP chemotherapy for the treatment of diffuse large B cell lymphoma in Japan: a retrospective analysis of 1,057 cases from Kyushu Lymphoma Study Group.

We performed a retrospective analysis of patients with diffuse large B cell lymphoma treated with rituximab plus CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) as a first-line therapy at 22 hospitals of the Kyushu Lymphoma Study Group. During the period 1996-2005, 1,057 patients (aged 22-90 years) were analyzed. Of these, 678 were treated with CHOP, and 379 were treated with rituximab plus CHOP (R-CHOP). The complete response rate was 59.9% in the CHOP group and 67.0% in the R-CHOP group (P < 0.001). Three-year progression-free survival (PFS) and overall survival (OS) rates were significantly higher in the R-CHOP group than in the CHOP group (61.3 vs. 45.6% for PFS, P < 0.001; 68.3 vs. 54.5% for OS, P < 0.001). The International Prognostic Index was a good prognostic marker for both groups; a survival benefit of rituximab addition was found for each risk subgroup and also for both age groups (60 years). Among 345 patients who received localized radiation therapy, the adding rituximab to CHOP attenuated the survival difference between CHOP and R-CHOP groups (P = 0.104), compared with no radiation group (P < 0.001). Results of this large-scale, multicenter study confirm that rituximab plus CHOP provided a greater survival benefit than CHOP alone.

Prognostic impact of immunohistochemical biomarkers in diffuse large B-cell lymphoma in the rituximab era.

We evaluated the usefulness of prognostic markers in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, vincristine, doxorubicin, and prednisolone (CHOP) +/- rituximab (R-CHOP) in Japan. We studied 730 patients with DLBCL; 451 received CHOP and 279 R-CHOP. We analyzed biopsy samples immunohistochemically for markers of germinal center B cells (CD10, Bcl-6), postgerminal center B cells (Multiple myeloma-1), and apoptosis (Bcl-2). The median follow-up period for surviving patients was 56.4 months for the CHOP group and 25.2 months for the R-CHOP group. DLBCL were categorized as germinal center B (GCB) subtype (352/730; 48.2%) or non-GCB subtype (378/730; 51.8%). In the CHOP group, the high expression of CD10 (P = 0.022) or Bcl-6 (P = 0.021), or GCB subtype (P = 0.05) was associated with better overall survival, whereas the high expression of Bcl-2 (P = 0.001) or MUM1 (P = 0.011), or non-GCB subtype (P = 0.05) was associated with worse overall survival. In the R-CHOP group, however, these biomarkers except Bcl-6 were not significant prognostic factors. The patients with non-GCB subtype showed improved survival in the R-CHOP group (P = 0.756). The International Prognostic Index was a useful clinical marker of survival in the CHOP group (P < 0.001) and also in the R-CHOP group (P < 0.001). Results of improved survival with rituximab addition indicate that the relevance of previously recognized prognostic factors should be re-evaluated.