The RML of lymph node metastasis was superior to the LODDS for evaluating the prognosis of gastric cancer

Abstract Objective The aim of the study was to investigate the most appropriate system for categorization of metastatic lymph nodes among N staging (according to the 7th edition UICC/AJCC TNM Classification for Gastric Cancer), ratio between metastatic and examined lymph nodes (RML) staging, negative lymph nodes (NLN) staging and log odds of positive lymph nodes (LODDS) staging for evaluation the overall survival (OS) of gastric cancer. Methods We reviewed clinicopathological data of 372 gastric cancer patients who underwent radical gastrectomy plus extended lymphadenectomy with the purpose of evaluating the differences in the OS according to different categories of metastatic lymph nodes. Results Univariate and multivariate analysis of data significantly identified the degree of differentiation (HR = 1.404, p = 0.015), T staging (according to the 7th edition UICC/AJCC TNM Classification for Gastric Cancer) (HR = 1.568, p = 0.024) and the RML staging (HR = 1.479, p = 0.030) as independent predictors of the OS. However, RML staging was identified as the most appropriate for evaluating the OS of gastric cancer patients following radical gastrectomy plus extended lymphadenectomy rather than N staging, NLN staging and LODDS staging by using the case–control matched analysis. With the further stratified analysis, we demonstrated that RML staging had the best prognostic homogeneity than LODDS staging, NLN staging or N staging. Conclusions RML staging was the best system for prediction the OS of the gastric cancer patients following radical gastrectomy plus extended lymphadenectomy, rather than LODDS staging, NLN staging or N staging.