Outcome after hematopoietic stem cell transplantation in patients with extranodal natural killer/T-Cell lymphoma, nasal type: A French study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC).

We evaluated the outcome of 65 French patients with Extranodal NK/T-cell lymphoma, nasal type (ENKTL) undergoing hematopoietic stem cell transplantation (HSCT) (19 allogeneic and 46 autologous). Fifty-four patients (83%), most of which receiving L-asparaginase (L-aspa) containing regimens (81%), achieved complete or partial response at time of HCST. After a median follow-up of 79.9 months, 4-years progression-free survival (PFS) and overall survival (OS) were similar in both autologous and allogeneic groups (PFS: 34% vs. 26%, p = .12 and OS: 52% vs. 53%, p = .74). Response status at HSCT was the major independent prognostic factor on survival (OS: HR: 4.013 [1.137; 14.16], p = .031 and PFS: HR: 5.231 [1.625; 16.838], p = .006). As compared to control patients receiving chemotherapy and/or radiotherapy containing regimens only, upfront HSCT did not improve the outcome of responder patients, including those treated by L-aspa. However, it tends to provide survival benefit for relapsed patients with initial high-risk clinical features who achieved second remission. Whereas the place of HSCT in upfront therapy has still to be clarified, these data confirm that HSCT should be considered for consolidation in selected patients with relapsed ENKTL. Based on a large non Asian ENKTL cohort since the L-aspa era, this study provides some insight into the survival patterns of ENKTL patients with HSCT in the Western hemisphere and may give future direction for the next clinical trial design.