Objectives: Extranodal natural killer/T-cell lymphoma (ENKTL) is a highly aggressive tumor of the sinonasal tract associated with poor overall survival (OS). This study expands upon epidemiologic, prognostic, and treatment factors for OS and disease-specific survival (DSS), incorporating newly accessible chemotherapy data.
Methods: Retrospective population-based cohort study performed on cases of sinonasal ENKTL identified through the Surveillance, Epidemiology, and End Results database. Univariate Kaplan-Meier analysis and subsequent multivariate Cox-regression analysis were performed to evaluate prognostic and treatment variables for OS and DSS.
Results: Four hundred and sixty cases of sinonasal ENKTL were identified. Five-year OS and DSS were 46% and 56%, respectively. On multivariate analysis, higher Ann Arbor stage was associated with worse OS (P < 0.001) and DSS (P < 0.001), whereas administration of radiotherapy was associated with improved OS (P < 0.001) and DSS (P = 0.001). Additionally, a higher age at diagnosis was associated with reduced OS (P = 0.024). Chemotherapy was associated with improved OS (P < .01) and DSS (P = .04) for Ann Arbor stage I disease. Surgery was not associated with improved survival.
Conclusion: This represents the first study to investigate the use of chemotherapy for the treatment of sinonasal ENKTL using population-based analysis. Radiation therapy and chemotherapy significantly improve survival in all Ann Arbor stage patients and early-stage patients, respectively. Early-stage disease is significantly associated with improved survival. With no established treatment regimen for sinonasal ENKTL, these findings suggest combination chemoradiation is an effective therapy for prolonged survival, especially in early stages of disease.
Level of evidence: 3 Laryngoscope, 129:2675-2680, 2019.
Keywords: ENKTL; NK/T-cell lymphoma; population database SEER; prognostic factors; sinonasal.
© 2019 The American Laryngological, Rhinological and Otological Society, Inc.