Risk‐based, response‐adapted therapy for early‐stage extranodal nasal‐type NK/T‐cell lymphoma in the modern chemotherapy era: A China Lymphoma Collaborative Group study

Abstract

We aimed to determine the survival benefits of chemotherapy (CT) additional to radiotherapy (RT) in different risk groups of patients with early‐stage extranodal nasal‐type NK/T‐cell lymphoma (ENKTCL) and to investigate the risk of postponing RT based on induction CT responses. A total of 1360 patients who received RT with or without new‐regimen CT from 20 institutions were retrospectively reviewed. The patients had received RT alone, RT followed by CT (RT+CT), or CT followed by RT (CT+RT). The patients were stratified into different risk groups using the nomogram‐revised risk index (NRI). A comparative study was performed using propensity score‐matched (PSM) analysis. Adding new‐regimen CT to RT (versus RT alone) significantly improved overall survival (OS, 73.2% vs. 60.9%, P < 0.001) and progression‐free survival (PFS, 63.5% vs. 54.2%, P < 0.001) for intermediate‐/high‐risk patients, but not for low‐risk patients. For intermediate‐/high‐risk patients, RT+CT and CT+RT resulted in non‐significantly different OS (77.7% vs. 72.4%; P = 0.290) and PFS (67.1% vs. 63.1%; P = 0.592). For patients with complete response (CR) after induction CT, initiation of RT within or beyond three cycles of CT resulted in similar OS (78.2% vs. 81.7%, P = 0.915) and PFS (68.2% vs. 69.9%, P = 0.519). For patients without CR, early RT resulted in better PFS (63.4% vs. 47.6%, P = 0.019) than late RT. Risk‐based, response‐adapted therapy involving early RT combined with CT is a viable, effective strategy for intermediate‐/high‐risk early‐stage patients with ENKTCL in the modern treatment era.