High incidence of esophageal fistula on patients with clinical T4b esophageal squamous cell carcinoma who received chemoradiotherapy: A retrospective analysis

Background and purposeDespite definitive chemoradiotherapy (CRT) being a recommended therapeutic method for patients with T4b esophageal squamous cell carcinoma (ESCC), treatment response and complications remain unclear. Esophageal fistula is a severe CRT-related complication when treating locally advanced ESCC, but data on risk factors that lead to esophageal fistula formation are limited. The aim of this analysis is to characterize the outcomes of T4b ESCC treated by CRT and investigate the risk factors of esophageal fistula.Materials and methodsWe retrospectively analyzed 136 patients with clinically unresectable T4b ESCC who were treated with CRT. Response, survival, and complication rates, particularly the rate of esophageal fistula and its associated risk factors were analyzed.ResultsThe median progression-free survival and overall survival (OS) of all patients were 7.9 (95% confidence interval [CI]: 6.1–9.7) and 12.2 months (95% [CI]: 8.9–15.4), respectively. The Kaplan–Meier curves showed that the 3- and 5-year OS rates were 29.9% and 20.2%, respectively. The incidence rate of esophageal fistulas was 30.1%. The median OS for patients with esophageal fistula was only 6.9 (95%[CI] = 6.0–7.8) months. The risk for developing esophageal fistulas was significantly high for ulcerative-type tumors (odds ratio [OR] = 3.202; 95%[CI] = 1.036–7.850, P = 0.011) and for those invading the bronchus/trachea (OR = 3.378; 95%[CI] = 1.223–9.332, P = 0.048).ConclusionWe demonstrated that CRT for T4b ESCC patients has a curative potential, despite a high incidence of esophageal fistula, which was the main cause of treatment failure. The higher risk for fistula formation were tumors with ulceration or bronchus/trachea invasion.