Effects of preoperative radiotherapy on survival of patients with stage II and III esophageal squamous cell carcinoma: A population-based study

The impact of preoperative radiotherapy (PRT) on survival in patients with stage II and III esophageal squamous cell carcinoma (ESCC) remains controversial. The aim of this study was to explore the effect of PRT on survival of these patients.Patients with stage II and III ESCC who underwent chemotherapy ± PRT were identified and retrieved from the SEER database from 2010 to 2015. Cox regression analysis was used to identify independent prognostic factors in patients. Subgroup analysis stratified by T stage and N stage was performed. Kaplan-Meier survival analysis was performed to assess disease specific survival (DSS).A total of 1160 patients were retrieved, of whom 289 (24.9%) underwent PRT plus chemotherapy, and 871 (75.1%) did not receive PRT. In multivariate analysis, PRT plus chemotherapy was a favorable prognostic factor for patients with stage T2 (hazard ratio [HR], 0.364, 95% CI, 0.202-0.658; P