Long-term outcome of diffuse large B-cell lymphoma: Impact of biosimilar rituximab and radiation.

INTRODUCTION: Rituximab (R)-CHOP improves survival over CHOP in diffuse large B-cell lymphoma (DLBCL). The availability of biosimilar rituximab in India has increased access of this drug. We report on the impact of treatment on outcomes with special emphasis on the impact of biosimilar rituximab and radiation. METHODS: Outcomes of adults (age 15-60 years) treated with CHOP+/- Rituximab radiation were analyzed retrospectively to look at baseline features, treatment, and event-free and overall survival (EFS and OS). RESULTS: In the period 2000-2013, 444 patients (median age 47 years: 15-60; males: 288 [65%]; Stage III/IV: 224 [50%]; age-adjusted international prognostic index [aaIPI] Score 2 or 3 in 50%) received either CHOP (n = 325 [73%]) or RCHOP (n = 119 [27%]) therapy. Biosimilar rituximab and the original were used in 95 (80%) and 24 (20%) patients, respectively. Radiation was given in 134 (30%) patients (Stages I and II, 100/220 [45%] and Stages III and IV, 34/224 [15%]). After a median follow-up of 46 (0.2-126) months, the 5-year EFS and OS were 59% and 68%, respectively. The factors predicting inferior EFS and OS were age> 40 years, performance status 2-4, Stage III/IV, hemoglobin <12 g/dL, the aaIPI Score 2 or 3, and nonuse of rituximab and radiation. Radiation used in early stage disease benefitted all subgroups regardless of bulky disease, use of rituximab, or the number of cycles of chemotherapy. Addition of rituximab improved survival across all categories of aaIPI. CONCLUSION: Availability of biosimilar rituximab has increased access and survival of patients with DLBCL in India. Radiotherapy improved outcomes in early stages.