Nasopharyngeal Carcinoma in Intensity-Modulated Radiation Therapy Era: Competing-Risk Analysis, Recurrence, and Postrecurrence Survival

Background: This study assessed long-term outcomes in nasopharyngeal carcinoma (NPC) patients treated with modern intensity-modulated radiation therapy (IMRT), focusing on recurrence patterns and postrecurrence survival (PRS). Methods: A cohort of 1554 NPC patients treated with definitive radiotherapy or concurrent chemoradiotherapy (CCRT) between 2005 and 2019 was analyzed using competing-risk models. Cumulative incidences of recurrence or death, local recurrence or death, regional recurrence or death, and distant recurrence or death were calculated, with subgroup differences evaluated by Gray's test. PRS was assessed using Kaplan–Meier curves, log-rank tests, and Cox proportional hazards models. Results: The 3-, 5-, and 10-year cumulative incidences of recurrence or death were 0.143, 0.162, and 0.187. T4 tumors showed poorer local control, and cumulative incidences of distant recurrence or death correlated with N classification. Most recurrences occurred within 2–3 years, with distant recurrences significantly reducing PRS. Conclusion: IMRT provides excellent local-regional control but requires improvement for T4 tumors and distant recurrences affecting PRS.