Impact of Extracapsular Lymph Node Involving the Esophagus in Esophageal Perforation During and After Radiotherapy: A Propensity Score-Matched Analysis

BACKGROUND: This study aimed to analyze the risk factors for esophageal squamous cell carcinoma (ESCC), especially extracapsular lymph node involving the esophagus (ECLNIE), occurring during or after radiotherapy (RT) in patients with esophageal perforation (EP). METHODS: In total, 306 patients with ESCC who received RT and/or chemotherapy between January 2016 and December 2017 in our hospital and who met the inclusion criteria of the study were recruited. The continuous variables were converted into classification variables using the receiver operating characteristic curve or common clinical parameters. Risk factors for EP were examined by univariable analysis using the chi-square test or Fisher’s exact and by multivariable analysis using logistic regression model. Propensity score matching (PSM) was used to compensate for the differences in baseline characteristics, and the incidence of EP was compared after matching. RESULTS: EP was observed in 26 patients (incidence rate, 8.5%). Univariable analysis revealed that age, BMI, T4 stage, tumor length, esophageal wall thickness, ECLNIE, necrotic areas, niche sign by esophagogram before RT, neutrophil-to-lymphocyte ratio, and prognostic nutritional index were significantly associated with EP among patients with ESCC who received radiotherapy. Multivariable analysis demonstrated that age, ECLNIE, esophageal wall thickness, and niche sign by esophagogram before RT were independent risk factors for EP. After PSM, compared with patients without ECLNIE, patients with ESCC and ECLNIE had a significantly higher risk of EP. CONCLUSION: The presence of ECLNIE could be a strong risk factor of EP during and after RT.