Impact of rituximab maintenance on survival in patients with mantle cell lymphoma: a population-based cohort study

ABSTRACT: Newly diagnosed mantle cell lymphoma (MCL) is commonly treated with rituximab (R), combined with anthracycline-based chemotherapy, with or without autologous stem cell transplantation (ASCT). Although R maintenance (RM) in clinical trials has been shown to prolong overall survival (OS), its impact at the population level remains largely unknown. This study evaluated the effect of RM on the outcome of patients with MCL. Patients aged ≥18 years, who were diagnosed with MCL between 1989 and 2020 were identified using the Netherlands Cancer Registry and were categorized into periods that reflected R and RM implementation (1989-2000, 2001-2014, 2015-2020). The treatment strategies were categorized as R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone); R-CHOP, followed by high-dose cytarabine (intensive) and ASCT; and other. The primary end point was 5-year OS. A multivariable analysis (MVA) was performed using Cox regression. Among 4751 patients, the 5-year relative survival (RS) improved from 38% (1989-2000) to 47% (2001-2014) and 60% (2015-2020) (P< .01), irrespective of age (≤65 years: 32% vs >65 years: 20% increase over time). Patients with progression within 12 months had a 2-year OS rate of 25%. Since 2014, RM implementation reached 80% in younger patients and 50% in older patients. RM was associated with improved OS, especially for patients in partial remission (PR) after induction treatment with R-CHOP. In the MVA of patients treated with R-CHOP, RM was independently associated with reduced mortality (hazard ratio, 0.69; 95% confidence interval, 0.53-0.90). The RS in MCL improved by >20% in 30 years. Early disease progression remains associated with poor outcome. RM was associated with improved survival, especially among patients who achieved PR following R-CHOP.