P1291: real-world data of long-term survivals in patients with mantle cell lymphoma who underwent stem cell transplantation

Topic: 22. Stem cell transplantation - Clinical Background: Mantle cell lymphoma (MCL) accounts for 6-7% of non-Hodgkin lymphoma, and is considered an incurable disease. The 5-year overall survival (OS) rates for patients with intermediate-, and high-risk mantle cell lymphoma international prognostic index (MIPI) groups are 35%, and 20%, respectively. To improve long-term survivals, autologous stem cell transplantation (auto-SCT), and allogeneic SCT (allo-SCT) may be therapeutic options for transplant eligible patients. Aims: In the current study, we evaluated the role of up-front SCT as a consolidation, and SCT as a part of salvage therapy. In addition, we compared survival benefits between auto-, and allo-SCT in various patient disease status. Methods: We retrospectively analyzed data from 209 patients with MCL who underwent auto-SCT or allo-SCT over the past 10 years. Patients aged ≥ 15 years were included in this study. Progression-free survival (PFS) was determined from the date of SCT to the date of disease progression or death from any cause. Overall survival (OS) was determined from the date of SCT to the date of death or last follow-up. Results: In total, 102 patients underwent up-front SCT as a consolidation therapy. Sixty-eight patients underwent SCT in complete remission (CR) status, in which 64 patients received auto-SCT. Thirty-four patients proceeded SCT in partial remission (PR) status, and 24 patients received auto-SCT while 10 patients received allo-SCT. The 3-year progression-free survival (PFS) and OS in patients with CR were 61.5% and 68.5%, respectively. The 3-year PFS and OS in patients with PR were 52.8% and 60.1%, respectively. Patients who underwent auto-SCT in CR status had significantly better PFS (p=0.005) and OS (p=0.025) than those who underwent allo-SCT. However, there were no significant survival differences between auto-SCT and allo-SCT in patients with PR status. Overall, 82 patients underwent SCT as a part of salvage therapy. Forty-one patients underwent SCT in CR/PR status, in which 19 patients (45.2%) received allo-SCT. Another 41 patients received SCT in relapsed/refractory disease status, and majority of patients received allo-SCT (36/41, 87.8%). In patients with CR, and PR, 2-year OS were 60.4%, and 53.6%, respectively. In patients with relapsed/refractory status, 2-year OS was 34.6%. Patients who received allo-SCT as a part of salvage therapy showed better tendency of OS than auto-SCT, but there was no statistical significance. Majority cause of poor outcomes in allo-SCT group was treatment related mortality (TRM). In the allo-SCT group, disease status at the time of SCT and reduced intensity conditioning regimen were identified as favorable factors for OS in multivariate analysis. Summary/Conclusion: As a consolidative therapy, up-front auto-SCT may improve survival benefits. If the disease persists or cannot be controlled, allo-SCT may be considered with reduced intensity conditioning. Figure 1. Kaplan-Meier curve. Overall survival according to the type of stem cell transplantation in patients who received salvage chemotherapy due to relapsed/refractory mantle cell lymphoma.Keywords: Mantle cell lymphoma, Autologous stem cell collection, Autologous hematopoietic stem cell transplantation, Allo-SCT