Addition of rituximab to chemotherapy alone as first-line therapy improves overall survival in elderly patients with mantle cell lymphoma

Abstract

Clinical trials have demonstrated that rituximab improves overall survival in non-Hodgkin lymphoma (NHL), except in mantle cell lymphoma (MCL). We used Surveillance Epidemiology and End Results (SEER)–Medicare data to compare survival in older MCL patients who began chemotherapy with or without rituximab within 180 days of diagnosis. Patients were followed from diagnosis (January 1999 to December 2005) until death or the end of observation (December 2007). Medicare administrative and claims data were used to identify the date and cause of death and the immunochemotherapy regimen. Of 638 patients, the mean age at diagnosis was 75 years, 75% had stage III/IV disease, 67% had extranodal involvement, and 64% received rituximab. The average length of first-line treatment was 21 weeks, with no difference between the 2 groups (P = .76). Median survival was 27 months for chemotherapy alone, compared with 37 months for chemotherapy plus rituximab (P < .001). In multivariate analysis of 2-year survival, rituximab plus chemotherapy was associated with lower all-cause (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.41-0.82; P < .01), and cancer-specific (HR 0.56; 95% CI 0.37-0.84; P < .01) mortality. Results were similar when using the entire observation period, propensity score analysis, and limiting chemotherapy to CHOP/CHOP-like. We conclude that first-line chemotherapy including rituximab is associated with significantly improved survival in older patients diagnosed with MCL.