Evaluation And Comparison Of Predictive Value Of Tumor Regression Grades According To Mandard And Becker In Locally Advanced Gastric Adenocarcinoma

Purpose:Neoadjuvant chemotherapy(NCT)is increasingly applied in malignancies of the gastrointestinal tract,which makes the evaluation of effectiveness pivotal.Pathologically,tumor-node-metastasis(TNM)system still has its limitations,for it is based on the location of residual tumor but not consider the amount.Tumor regression grade(TRG),a quantitative approach to describe remaining carcinoma,could be a supplement to TNM.However,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;p=0.017).The Becker TRG was also related to OS(HR,1.880;p=0.014)and DFS(HR,1.919;p=0.006).The Mandard and Becker TRG AUCs for five-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.