Abstract
BACKGROUND: Prior research, characterized by small patient cohorts, has yielded limited understanding of the effects of radiotherapy (RT) on distant nasopharyngeal carcinoma (dNPC). Therefore, we aim to examine the impact of RT on survival outcomes in dNPC utilizing a large-scale population database. METHODS: Clinical data from 1,171 dNPC patients in the Surveillance, Epidemiology, and End Results (SEER) registry [2004-2019] was retrospectively analyzed. Among them, 227 (19%) did not receive RT, while 944 (81%) did. The primary outcome was overall survival (OS). Kaplan-Meier analysis was used to assess the survival of patients, and differences between treatment groups were evaluated using the Log-rank test and Cox's regression model. Nomogram was established to predict patient survival time and the model was evaluated using receiver operating characteristic (ROC) curves. RESULTS: The median survival duration for all patients was 33 months, with a range spanning from 0 to 215 months. RT was associated with significantly improved OS [hazard ratio (HR): 0.35, 95% confidence interval (CI): 0.29-0.43, P<0.001]. According to the Cox proportional hazards model, the HR for patients who did not receive RT was 2.83 times higher compared to those who underwent RT. The nomograms for predicting 1-, 3-, and 5-year OS demonstrated moderately good calibration and discrimination, with a concordance index of 0.71. The areas under the curves (AUCs) of ROC for 1-, 3-, and 5-year OS were 0.762, 0.763, and 0.750 respectively. CONCLUSIONS: Our research revealed the significance of RT in the treatment of dNPC, and RT can serve as an independent predictor of survival, which might contribute to the creation of guidelines for dNPC.