Evolution of Rituximab as “Standard” Therapy in Patients (pts) with Newly Diagnosed Diffuse Large B Cell Lymphoma (DLBCL) in Japan: An Analysis from West-Japan Hematology/Oncology Group (West-JHOG) NHL Outcomes Project.

The addition of rituximab to the CHOP (R-CHOP) regimen has had a dramatic impact on therapy of B-NHL. To clarify the effect of rituximab plus CHOP, we conducted a retrospective multicenter analysis to compare clinical outcomes of R-CHOP and CHOP in Japanese patients with diffuse large B cell lymphoma (DLBCL). Between 1/2000 and 6/2005, unselected 293 Japanese patients with DLBCL recruited from 13 institution, received CHOP with or without rituximab as the first line therapy. CHOP or R-CHOP was given 3 courses following radiotherapy for localized, and 6–8 courses for advanced disease. Rituximab was given at 375 mg/m² concurrently with each course. The median age of total patients was 68 (range 26–99). After median follow-up of 21 months, PFS at 1, 2 year was 70.7% (95% confidence interval [CI]; 64.9–75.8), 59.1%(95%CI;64.9–75.8), respectively. Ninety-six patients received rituximab in combination with CHOP and 197 patients received CHOP alone. No statistically significantly differences of clinical characteristics such as sex, age and international prognostic index (IPI) were documented between two groups. The median follow-up for living patients was 15 and 28 months for R-CHOP and CHOP, respectively. In multivariate analysis, R-CHOP therapy significantly reduced the risk of treatment failure (hazard ratio [HR] 0.62; 95%CI 0.40–0.96, p=0.033), although the risk of death was similar in both group (HR0.78; 95%CI 0.44–1.37, p=0.38). In conclusion, in this multicenter analysis, R-CHOP therapy prolongs progression-free survival in Japanese DLBCL patients. There was a trend to better OS with rituximab than without rituximab at 2-year, however, this was not statistically significant. Longer follow-up will be required to assess the effect rituximab plus CHOP on survival.