Intensive Induction Regimens after Deferring Initial Therapy for Mantle Cell Lymphoma Are Not Associated with Improved Survival.

INTRODUCTION While most patients with mantle cell lymphoma (MCL) receive therapy shortly after diagnosis, a subset of patients with indolent-behaving disease can safely defer treatment. In this subgroup, we evaluated the importance of treatment intensity in patients with MCL who defer initial therapy. METHODS Out of 1134 patients with MCL from 12 academic centers, we analyzed 219 patients who initiated therapy at least 90 days after diagnosis. Patients who received induction with high dose cytarabine and/or autologous stem cell transplantation (ASCT) in first remission were considered to have received intensive therapy (n=88) while all other approaches were non-intensive (n=131). RESULTS There was no difference in progression-free (PFS; p=0.224) or overall survival (OS; p=0.167) in deferred patients who received non-intensive vs. intensive therapy. Additionally, univariate and multivariate Cox proportional hazards models were performed for PFS and OS. Treatment at an academic center (HR 0.43, p=0.015) was associated with improved OS in both univariate and multivariate models, while intensity of treatment was not associated with improved OS in either model. CONCLUSIONS These results indicate that intensified initial treatment is not associated with improved survival after deferring initial therapy, although prospective studies are needed to determine which of these patients with MCL may benefit from intensive therapy.