Outcomes of transplant-eligible and transplant-ineligible patients with mantle cell lymphoma in Ontario.

The frontline treatment of patients with mantle cell lymphoma (MCL) varies in practice. We conducted a retrospective, population-based study of patients with MCL from 2005 to 2020. We defined transplant-eligible (TE) patients as those aged <70 years who received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) or R-CHOP/R-DHAP (rituximab, dexamethasone, high-dose cytarabine and dexamethasone) and transplant-ineligible (TI) patients as those aged ≥70 years and treated with bendamustine-rituximab (BR) or other chemoimmunotherapy regimens. The primary outcome was 5-year overall survival (OS), and secondary outcomes included toxicities and health care use. We identified 426 TE patients, of whom 254 received R-CHOP and 172 received R-CHOP/R-DHAP. More patients who received R-CHOP/R-DHAP also received an autologous stem cell transplant (ASCT). The 5-year OS for patients treated with R-CHOP/R-DHAP was 70.5% compared with 62.0% for patients treated with R-CHOP, regardless of transplant status. R-CHOP/R-DHAP had more hospital admissions for fever, infection, neutropenia, and renal toxicity. TI patients received BR (n = 303) or historical regimens (n = 189). BR was associated with lower mortality. After adjustment, maintenance rituximab was associated with significantly lower mortality (hazard ratio, 0.33; 95% confidence interval, 0.24-0.44). More patients treated with BR had hospital admissions for febrile neutropenia. In this large population-based study, R-CHOP/R-DHAP before ASCT showed a trend toward improved 5-year OS. BR did not result in superior OS after adjustment, suggesting other regimens followed by rituximab maintenance may be reasonable.