The Prognostic Value Of Lymph Node Staging Indexes In Adenocarcinoma Of Stomach And Esophagogastric Junction After Neoadjuvant Therapy

Research background and objectivesAccurate lymph node stage is very important for patients with adenocarcinoma of stomach and esophagogastric junction who have undergone neoadjuvant therapy and radical surgery.At present,the 8th edition AJCC/UICC TNM stage defines the ypN stage according to the number of lymph nodes metastasis.It is recommended to harvest at least a certain number of lymph nodes to accurately evaluate the lymph node status.However,neoadjuvant therapy increased the number of node-negative patients as well as those with insufficient examined lymph nodes(ELN),and it may not accurately assess lymph node status.At present,several different lymph node staging indexes have been proven to be alternative indicators of ypN stage.However,there was a lack of verification in patients with adenocarcinoma of stomach and esophagogastric junction after neoadjuvant therapy.Therefore,it has important clinical significance to identify the best staging indexes among ypN,lymph node ratio(LNR),log odds of positive lymph node(LODDS),and negative lymph node(NLN)and the application of joint indexes for the prediction of prognosis in these patients.Methods and Materials1.Data was collected from the Surveillance,Epidemiology,and End Results(SEER)database and 1551 patients with gastric adenocarcinoma who underwent neoadjuvant therapy and radical surgery were collected.Harrell’s concordance index,the likelihood ratio test(LR test),and the Akaike information criterion(AIC)were used to compare the predictive abilities of the different staging indexes.2.Furthermore,we explored the predictive performance of the Nr stage,based on the NLN and LNR,for AEG patients who underwent neoadjuvant radiation therapy and radical surgery.632 AEG patients were collected from SEER database.The predictive performance of the indexes was compared using the time-dependent Harrell’s Concordance index,time-dependent Receiver Operative Curve(ROC),LR test,and AIC.Results1.Among the 1551 patients,when lymph node indexes were regarded as the categorical variables,LNR had better predictive performance compared to other stage indexes,regardless of the status of ELN.When regarded as the continuous variables,LODDS outperformed others for patients with ELN≥16.Furthermore,the NLN staging index performed superior to others in node-negative patients.2.Among the 632 AEG patients,patients with ELN<15 were 349(55.2%),and node-negative patients were 198(31.88%).The Nr staging index had predictive performance for prognosis compared to other indexes,particularly in patients with inadequate ELN.Conclusions1.For patients with gastric adenocarcinoma who underwent neoadjuvant therapy and radical surgery,LNR had a better predictive performance than ypN,LODDS and NLN staging indexes regardless of the status of ELN when regarded as the categorical variable,whereas LODDS became the better predictive indexes for patients with ELN≥16 when regarded as the continuous variable.In node-negative patients,NLN might be a feasible option for evaluating prognosis.A combination of LNR and NLN should be considered as user-friendly method in the clinical prognostic assessment.2.For AEG patients who underwent neoadjuvant radiation therapy and radical surgery,the Nr staging index is developed with prognostic superiority to ypN,LNR,LODDS,and NLN staging indexes,especially in patients with inadequate ELN.The Nr staging index may serve as a practical tool in clinical prognostic assessment and postoperative treatment decision making.