HEMATOPOIETIC STEM CELL TRANSPLANT IN AGGRESSIVE T AND NK/T CELL LYMPHOMA - ROLE OF UPFRONT AUTOLOGOUS TRANSPLANT IN NODAL PERIPHERAL T-CELL LYMPHOMA.

Aggressive T and NK/T-cell lymphoma are known to have a high risk of relapse and poor long-term prognosis. Hematopoietic stem cell transplantation has been performed as part of consolidation or salvage treatment. We retrospectively studied the outcomes of autologous (A) and allogeneic (allo) hematopoietic stem cell transplantation (SCT) in aggressive T and NK/T-cell lymphoma at our center between 2010 to 2020. Patients with nodal peripheral T-cell lymphoma (PTCL) that were younger than 65 years old who did not receive upfront autologous SCT (ASCT) at first complete remission were selected from our registry data for further comparison. Thirty-six patients underwent ASCT, and 16 patients underwent alloSCT. In the ASCT cohort, 18 patients with nodal PTCL who underwent upfront ASCT at first complete remission (upfront ASCT) were compared with 15 patients with nodal PTCL who were in first complete remission after single-line induction but did not receive ASCT. The two-year progression-free survival (PFS) and overall survival (OS) rates for the ASCT cohort were 58% and 73%, respectively. The two-year PFS and OS for the alloSCT cohort were 47% (=0.35, =0.02, respectively). Twenty-four patients who received SCT at first remission (21 ASCT and three alloSCT) had a two-year PFS and OS of 75% and 89%, respectively. In comparison, 28 patients who received SCT at relapse/refractory (15 ASCT and 13 alloSCT) had a two-year PFS and OS of 40% and 50%, respectively (=0.047, =0.024, respectively). Patients in complete remission prior to transplantation (n=42) had a two-year PFS and OS of 59% and 73%, respectively. In contrast, patients in partial remission prior to transplantation (n=10) had a two-year PFS and OS of 40% and 48%, respectively (p>0.05). Non-relapse mortality occurred in 6% and 43% of ASCT and AlloSCT, respectively. Multivariate analysis revealed that EBV-positivity at diagnosis indicated poorer PFS. EBV-positivity at diagnosis and more than two prior lines of treatment at transplant were associated with poorer OS. For nodal PTCL, the two-year PFS and OS were 79% and 100% for the upfront ASCT cohort and 78% and 92% for the non-upfront ASCT cohort, respectively (p>0.05). Hematopoietic SCT is a feasible treatment option for aggressive T and NK/T-cell lymphoma. Patients who underwent SCT at first remission had better survival rates than those who underwent SCT at relapse/refractory. Nevertheless, due to the limited sample size of the current study, the role of upfront ASCT in patients with nodal PTCL who achieved first complete remission remains unclear.