Dose escalation intensity-modulated radiotherapy-based concurrent chemoradiotherapy is effective for advanced-stage thoracic esophageal squamous cell carcinoma

Purpose: No studies have investigated the effects of irradiation-dose escalation intensity-modulated radiotherapy (IMRT)-based concurrent chemoradiotherapy (CCRT) in patients with thoracic esophageal squamous cell carcinoma (TESCC). Patients and methods: We analyzed data from patients with TESCC who were enrolled in the Taiwan Cancer Registry database. To compare treatment outcomes, the patients were categorized into two groups according to their radiotherapy doses: group 1, who received CCRT < 60 Gy with IMRT, and group 2, who received CCRT >= 60 Gy with IMRT. Group 1 was used as the control for investigating post-treatment mortality risk. Results: We enrolled 2061 patients with TESCC without distant metastasis who received CCRT with IMRT. Multivariate Cox regression analysis indicated that advanced clinical American Joint Committee on Cancer (AJCC) stage (>= IIIA), alcohol consumption, and cigarette smoking were significant, poor independent predictors in patients with TESCC receiving IMRT-based CCRT. IMRT-based CCRT (>= 60 Gy; adjusted hazard ratio [aHR]: 0.75; 95% confidence interval [CI]: 0.63-0.83) was a significant independent prognostic factor for overall survival (P < 0.0001). After adjustment for confounders, the aHRs (95% CIs) for overall mortality at all clinical stages were 0.75 (0.68-0.83, P < 0.0001) in group 2. In group 2, the aHRs (95% CIs) for overall mortality at early (IA-IIB) and advanced (IIIA-IIIC) AJCC clinical stages were 0.89 (0.70-1.04, P = 0.1905) and 0.75 (0.67-0.83, P < 0.0001), respectively. Conclusion: Compared with standard-dose IMRT-based CCRT, high-dose IMRT-based CCRT yields more favorable survival outcomes in patients with advanced-stage TESCC. (C) 2017 Elsevier B.V. All rights reserved.