Role of rituximab in the first-line therapy of high-risk diffuse large B-cell lymphoma: a retrospective analysis by the Polish Lymphoma Research Group.

INTRODUCTION: R-CHOP immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) is a standard first-line treatment for diffuse large B-cell lymphoma (DLBCL). None of the randomized trials have proved a statistically significant overall survival (OS) benefit in high-risk subgroups according to the International Prognostic Index (IPI).

OBJECTIVES: We retrospectively investigated the role of adding rituximab to anthracycline-based chemotherapy in patients with high-risk DLBCL according to the IPI.

PATIENTS AND METHODS: A total of 371 patients with high-risk DLBCL treated at 15 Polish hematology centers were retrospectively analyzed in 2 distinct age groups: older than 60 years and 60 years old or younger. Response rates, OS, and progression-free survival (PFS) were compared and analyzed.

RESULTS: The overall response rate (ORR) of high-risk DLBCL patients significantly improved in rituximabtreated patients compared with patients treated without rituximab (76.7% vs 95.6%; P <0.05). The R-CHOP immunochemotherapy prolonged survival in both older and younger subgroups. The 5-year projected OS and PFS in younger patients treated with rituximab vs chemotherapy alone were 42% vs 38% and 46% vs 27%, respectively (P <0.05), while the 5-year projected OS and PFS in older patients treated with rituximab vs chemotherapy alone were 82% vs 52% and 67% vs 45%, respectively (P <0.05).

CONCLUSIONS: With all the limitations of a retrospective analysis, the superiority of adding rituximab to CHOP combination chemotherapy has been clearly demonstrated regarding ORR, OS, and PFS in both age subgroups of patients with high-risk DLBCL.