Efficacy of concurrent chemoradiotherapy in subgroups of stage III nasopharyngeal carcinoma: an analysis based on 10-year follow-up

PURPOSE: To evaluate the efficacy of concurrent chemoradiotherapy (CCRT) in subgroups of stage III nasopharyngeal carcinoma (NPC) in the context of intensity-modulated radiotherapy (IMRT). METHODS: A total of 272 patients with stage III NPC who underwent IMRT with or without concurrent chemotherapy were retrospectively reviewed. Clinicopathological features were evaluated by a Cox regression model to identify independent prognostic factors. Survival outcomes were assessed using the Kaplan–Meier method and log-rank test. RESULTS: The median follow-up time was 108 months. The 10-year locoregional-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) rates were 87.8%, 80.7%, 68.8%, and 74.9%, respectively. Multivariate analysis showed that the N classification was significantly associated with DMFS (hazard ratio [HR] 3.616, 95% confidence interval [CI] 1.387–9.428, P = 0.009), DFS (HR 2.417, 95% CI 1.291–4.423, P = 0.006), and OS (HR 3.024, 95% CI 1.385–6.602, P = 0.005). In patients with T1-3N2 disease, CCRT was associated with improved 10-year LRFS (89.6% vs. 65.4%, P = 0.005), DFS (71.9% vs. 39.4% P = 0.001) and OS (80.0% vs. 50.5%, P = 0.004) compared with IMRT alone. However, in patients with T3N0-1 disease, no significant survival differences were observed between patients treated with IMRT alone and CCRT (P > 0.05). CONCLUSIONS: CCRT is an effective therapy in stage III NPC, especially for patients with N2 disease, but IMRT alone may be adequate for N0-1 disease. Individualized treatment strategies are essential for patients with varying disease risks. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13014-021-01929-9.