Addition of Rituximab Improves Progression-Free and Overall Survival in Patients with B-Cell Lymphoma Receiving Doxorubicin-Containing Chemotherapy

Background: Many clinical trials have documented the efficacy of rituximab in B-cell lymphomas. However, it remains unclear whether rituximab will improve long-term prognosis of the patients. This multicenter retrospective cohort study was conducted to evaluate the clinical impact of the drug in the treatment of B-cell lymphomas. Study design: We retrospectively analyzed clinical characteristics, 2-year progression-free survival(2y PFS) and 2-year overall survival(2y OS) of all B-cell lymphoma patients who were newly diagnosed and initially treated with either CHOP-like regimen alone (R(−) group) or in combination with rituximab (R(+) group) between 2000 and 2004 at our 20 hospitals belonging to the National Hospital Organization. Since rituximab was approved in 2002 for indolent B-cell lymphomas and in 2003 for aggressive B-cell lymphomas in Japan, the patients were almost automatically divided into the 2 groups dependent on the year they underwent treatment.

Results: Of the 1,072 patients enrolled, 335 were given rituximab, while 737 did not receive it for the initial induction therapy. 2y PFS was 74.3% and 61.2% for R(+) group and R(−) group, respectively(P<.0001). 2y OS also significantly improved with the addition of rituximab, 86.6% vs 65.3%(P<.0001). In 746 patients with diffuse large B-cell lymphoma, R(+) group (183 patients) and R(−) group (563 patients) showed 2y PFS of 71.6% and 62.2% (P=.0017), 2y OS of 78.5% and 62.5% (P<.0001) respectively. In 195 patients with follicular lymphoma, R(+) group (104 patients) and R(−) group (91 patients) exhibited 2y PFS of 80.1% and 64.5% (P<.0001), 2y OS of 94.9% and 81.5% (P<.0001), respectively.

Conclusion: The addition of rituximab to the chemotherapy regimen significantly improves the clinical outcome in patients with previously untreated B-cell lymphoma regardless of the clinical aggressiveness.