Treatment and prognosis of newly diagnosed advanced-stage extranodal natural killer / T cell lymphoma: a single-center real-world study across two decades.

INTRODUCTION: Although there is now a consensus on asparaginase-based chemotherapy regimens in treatment of advanced-stage extranodal natural killer / T cell lymphomas (ENKTCLs), patient survival in the real-world setting is still not optimistic according to previous literature reports, and the optimal chemotherapeutic regimens and integration of different therapeutic methods under the concept of combined-modality treatment still need to be further explored and verified. METHODS: Newly diagnosed stage Ⅲ / Ⅳ ENKTCL patients from Chinese National Cancer Center in the last two decades were retrospectively collected and analyzed. Overall survival (OS) and progression-free survival (PFS) were determined as primary endpoints. Log-rank tests and Cox proportional hazard models were performed to test for survival differences between subgroups and examine the univariable and multivariable associations. RESULTS: The study included 83 newly diagnosed stage Ⅲ / Ⅳ ENKTCL patients and reported a median OS of 26.07 months and an estimated 5-year OS of 41.3% with a median follow-up of 82.13 months. First-line asparaginase- compared to non-asparaginase-based regimens significantly prolonged PFS (P=0.007; HR=0.48, P=0.020) and showed a tendency to improve OS (P=0.064; HR=0.74, P=0.359). Gemcitabine-based regimens also exhibited a trend towards improved PFS (P=0.048; HR=0.59, P=0.164) and OS (P=0.008; HR=0.67, P=0.282) compared to non-gemcitabine-based ones. The asparaginase and gemcitabine combinations yielded a 5-year OS of 55.0% and led to significantly superior PFS (P=0.020; HR=0.40, P=0.022) and slightly better OS (P=0.054; HR=0.79, P=0.495) compared to the remaining regimens. First-line combined-modality treatment integrating chemotherapy and radiotherapy improved PFS (P=0.051) and OS (P=0.036) compared to chemotherapy alone. Four autologous hematopoietic stem cell transplantation recipients reached a median OS of 58.34 months. CONCLUSION: Asparaginase and gemcitabine alone brought favorable impact on PFS and OS; and the asparaginase and gemcitabine combination chemotherapy yielded the optimal efficacy, response duration and survival outcomes. Combined-modality treatment including potent chemotherapy supplemented by radiotherapy and/or consolidative transplantation could improve prognosis in newly diagnosed advanced-stage ENKTCLs.