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

• In transplant-eligible mantle cell lymphoma, the use of RCHOP/RDHAP increases toxicity and healthcare utilization. • For transplant-ineligible patients, the improved overall survivor appears to be from maintenance rituximab. 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 less than 70 who received R-CHOP or R-CHOP/R-DHAP and transplant ineligible (TI) as > 70 and treated with BR or other chemoimmunotherapy regimens. The primary outcome was 5-year overall survival (OS), and secondary outcomes included toxicities and healthcare utilization. 426 TE patients were identified: 254 received R-CHOP, and 172 received R-CHOP/R-DHAP. More patients who received R-CHOP/R-DHAP also received an ASCT. 5-year OS of patients treated with R-CHOP/R-DHAP was 70.5% vs 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 (HR 0.33, 95% CI 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 prior to ASCT showed a trend toward improved 5-year OS. BR did not result in superior OS after adjustment, suggesting other regimens followed by MR may be reasonable.