Prognostic factors and implications of multimodal treatment in sinonasal neuroendocrine tumors: insights from the SEER database

Purpose Sinonasal neuroendocrine carcinomas (SNECs) are rare and aggressive malignancies with heterogeneous histopathology and limited evidence guiding optimal treatment. This study aims to characterize clinicopathological features, treatment patterns, and prognostic factors using a large population-based database. Methods We queried the SEER database (2000–2022) for histologically confirmed SNECs. Kaplan-Meier analysis was used to estimate overall survival (OS) and disease-specific survival (DSS). Univariate and multivariate Cox models were employed to identify independent prognostic factors. Results A total of 389 cases were identified, mostly male (58.4%) with a median age of 60 years and nasal cavity as primary site (48.1%). Neuroendocrine carcinoma not otherwise specified (50.1%) was the most frequent, followed by small cell (35.0%) and large cell carcinoma (10.5%). Nearly 38% of patients presented with metastatic disease. Surgery, radiotherapy, and chemotherapy were administered in 54.1%, 66.9%, and 69.9% of cases, respectively. Kaplan-Meier analysis showed improved OS and DSS in patients with localized/locally advanced stage, lower tumor grade, nasal cavity primary site, and those treated with surgery, radiotherapy (particularly adjuvant), or chemotherapy (all p < 0.05). In multivariate models, primary sites outside the nasal cavity were independently associated with worse OS and DSS, while surgery and radiotherapy remained the only treatment modality significantly associated with improved outcomes. Conclusion In this large population-based study, SNECs were characterized by advanced-stage presentation and use of multimodal therapy. Radiotherapy was independently associated with improved OS/DSS in multivariable models, supporting aggressive local treatment in SNECs and underscoring the need for therapeutic strategies tailored to disease stage and tumor location.