Effect of number of metastatic lymph nodes and metastatic lymph node ratio on the prognosis in patients with adenocarcinoma of the esophagogastric junction after curative resection

Objective To analyze the effects of number of positive lymph nodes and metastatic lymph node ratio (LNR) in evaluation of recurrence risk and overall survival in patients with adenocarcinoma of the esophagogastric junction (AEG) after curative resection.Methods Clinical data of 337 AEG patients who underwent curative resection in our hospital were retrospectively reviewed.The pN stage was categorized based on the number of metastatic lymph nodes and LNR stage,and was determined by the best cutoff approach at log-rank test.Univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model were used to analyze the effects of pN and LNR on recurrence-free survival and overall survival of these patients.Receiver operating characteristic (ROC) curves were plotted to compare the accuracy of prognosis prediction with pN and LNR.Results The 5-year recurrence-free survival rate and overall survival rate for all patients were 25.5％ and 29.9％,respectively.The 5-year recurrence-free survival rates were 47.6％,23.2％,17.1％ and 5.7％ for pN0,pN1,pN2,and pN3,respectively,(P＜0.001) and the 5-year overall survival rates were 53.3％,28.9％,18.9％ and 7.3％,respectively (P ＜ 0.001).The 5-year recurrence-free survival rates were 47.6％,24.3％,11.4％ and 2.0％ for LNR0,LNR1,LNR2,and LNR3,respectively (P ＜ 0.001),and the 5-year overall survival rates were 53.3％,28.5％,15.0％,2.6％,respectively (P ＜0.001).Univariate analysis showed that tumor size,macroscopic type,degree of differentiation,pT,pN,LNR and TNM stage were significantly associated with RFS and OS (P ＜ 0.05).Cox multivariate analysis showed that either pN or LNR was independent risk factor for RFS and OS (P ＜0.001).When pN and LNR were entered into the Cox hazard ratio model as covariates at the same time,LNR remained as an independent prognosis factor for RFS and OS (P ＜ 0.001),but pN was not (P ＞ 0.05).ROC curves showed that the area under the curve of LNR stage was larger than that of pN stage in prediction of both RFS and OS,however the differences were not statistically significant (P ＞ 0.05).Conclusions LNR is an independent risk factor associated with the prognosis of AEG patients.The value of LNR in prediction of recurrence hazard and overall survival was better than that of pN stage.It offers some helpful suggestions for AEG patients risk classification,allowing clinicians to develop a reasonable treatment. Key words: Esophageal neoplasms;  Stomach neoplasms;  Lymphatic metastasis; Prognosis ;  Factor analysis, statistical