Risk factors and prognosis for esophageal fistula in patients with esophageal squamous cell carcinoma during radiotherapy

Purpose To determine risk factors, treatment outcomes, and prognostic factors for esophageal fistula (EF) in patients with esophageal squamous cell carcinoma (ESCC) during radiotherapy. Methods Between 2010 and 2018, 109 patients with EF during radiotherapy were retrospectively collected. A controlled cohort including 416 patients who received definitive chemoradiotherapy without EF was used to compare risk factors and survival outcomes. Univariate and multivariate logistic regression analyses were performed to identify predictors of EF. Propensity score matching (PSM) was applied to adjust for potential confounding factors. Results Multivariate analysis demonstrated that sex, body mass index, alcohol history, esophageal ulceration, primary tumor length, T stage, and absolute lymphocyte count were independent risk factors for EF. After PSM, patients with EF showed remarkably worse prognosis than those without EF (median overall survival: 13.0 versus 20.5 months; P = 0.009). For patients with EF, serum albumin level (≥ 35 g/L), subsequent radiotherapy, and fistula closure were associated with significantly prolonged survival. In addition, esophageal-mediastinum fistula and subsequent radiotherapy were positive predictors for fistula closure. Conclusions We identified risk factors for radiotherapy-related EF and its unfavorable prognosis in patients with ESCC. Of them, patients with serum albumin level of ≥ 35 g/L, subsequent radiotherapy after EF, and fistula closure had a more favorable survival.