Value of Combining the Number of Lymph Node Stations and Tumor Regression Grade in the Neoadjuvant Treatment of Esophageal Cancer

Background The aim of this study is to evaluate whether TRG system is more valuable than ypT stage in evaluating the prognosis of esophageal cancer, and to compare the efficacy of TRG system with the modified TRG system of S stage in predicting the prognosis of patients with esophageal cancer after neoadjuvant therapy. Methods Kaplan–Meier method and log-rank test were used to analyze survival differences stratified by TRG or number of lymph node stations. Univariate and multivariate Cox proportional hazards models were used to analyze the independent prognostic factors of esophageal cancer patients with nCRT. C-index and calibration curve were used to evaluate and compare the accuracy and discrimination of the two prediction models. Decision curve analysis (DCA) was used to evaluate the clinical value of the two prediction models. Results A total of 514 patients were included in the study. TRG stage was not an independent prognostic factor for patients with esophageal cancer after nCRT in multivariate analysis (HR = 1.06,95%CI: 0.57–1.97,P = 0.845). The new tumor regression grade (nTRG) system constructed by combining new S (nS) staging with TRG and ypTNM staging are independent prognostic risk factors for patients. Time-ROC curve, DCA, NRI and other predictive indicators proved that nTRG stage was comparable or even better than ypTNM stage. Conclusion nTRG staging can be used as a survival prediction and treatment monitoring indicator for patients with esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy, and the performance of the related model is better than that of ypTNM staging.