Prognosis of different irradiation methods in patients with T2-3N0M0 esophageal squamous cell carcinoma

Objective To evaluate the effect of different irradiation methods on the long-term prognosis of patients with clinical T2-3N0M0 esophageal squamous cell carcinoma, aiming to select the optimal treatment for these patients. Methods A total of 268 eligible patients admitted to our hospital from January 2007 to December 2012 were enrolled in this study. All patients were divided into the involved-field irradiation (IFI) and elective node irradiation (ENI) groups. The composition ratio, prognostic factors and adverse events were analyzed between two groups. Results The median overall survival (OS) time was 35.5 months (95%CI : 30.12-40.88) and the median disease-free survival (DFS) time was 23.5 months (95%CI: 19.00-28.00). According to the multivariate analysis results, all patients were assigned into two groups at a ratio of 1 vs.1(n=86 in each group). Multivariate analysis after propensity score matching (PSM) demonstrated that irradiation method was the independent factor of OS (P=0.038), and T stage and radiotherapy were the independent factors affecting DFS (P=0.002, 0.032). The incidence of ≥grade Ⅱ adverse events did not significantly differ between two groups (P=0.819, 0.756). However, patients with combined chemotherapy experienced more adverse events. Conclusion ENI can prolong the OS and DFS of patients with clinical T2-3N0M0 esophageal squamous cell carcinoma, and does not increase the incidence of severe adverse events. Key words: Esophageal neoplasm/involved-field irradiation; Esophageal neoplasm/elective node irradiation; Prognosis