Evaluation and Comparison of Predictive Value of Tumor Regression Grades According to Mandard and Becker in Locally Advanced Gastric Adenocarcinoma

Purpose Tumor regression grade (TRG) has been widely used in gastrointestinal carcinoma to assess pathological responses to neoadjuvant chemotherapy (NCT). There are various standards without a consensus, and it is still unclear which kind of system has better predictive value. This study aims to investigate and compare the predictive ability of the Mandard and Becker TRGs in patients with locally advanced gastric cancer. Materials and Methods A total of 290 patients with locally advanced gastric adenocarcinoma who underwent NCT and curative surgery were studied. Survival analysis for overall survival (OS) and disease-free survival (DFS) were based on the Kaplan-Meier method and Cox proportional hazards method. Predictive values of TRGs and models were assessed by time-dependent receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), nomogram, and calibration curve. Results In multivariable analysis, the Mandard TRG was associated with OS (hazard ratio [HR), 1.806; p=0.026) and DFS (HR, 1.792; 1)=0.017). The Becker TRG was also related to OS (HR, 1.880; p=0.014) and DFS (HR, 1.919;1)=0.006). The Mandard and Becker TRG AUCs for 5-year survival were 0.72 and 0.71, respectively. The whole models showed an increased predictive value, with AUCs of 0.85 and 0.86, respectively. There was no significant difference between the two TRGs and two models. Conclusion TRG was an independent predictor for survival, and there was no significant difference between these two systems.