Suitability of 7th UICC N Stage for Predicting the Overall Survival of Gastric Cancer Patients After Curative Resection in China

Metastatic lymph node count (MLNC) is the most intensively prognostic indicator of gastric cancer. How to efficiently evaluate the best classification of MLNC is unclear. The purpose of this study was to evaluate the overall survival (OS) prediction of new UICC N stage in gastric cancer after curative surgery. Data from 456 patients who underwent curative resection were used to choose the most efficient classification of MLNC for evaluation the OS of gastric cancer. Using univariate analysis, both the N stage of 7th edition UICC TNM classification (7th UICC N stage) and N stage of 5th/6th edition UICC TNM classification (5th/6th UICC N stage) were associated with the OS of gastric cancer after curative surgery. However, Cox regression multivariate analysis showed the 7th UICC N stage was an independent factor for predicting the OS of gastric cancer instead of the 5th/6th UICC N stage. Besides, we used the case-control matched fashion for further validation of the superiority of the 7th UICC N stage in prognostic prediction of gastric cancer. Last, we adopted the cut-point survival analysis to determine the most appropriate cutoffs for MLNC of all gastric cancer patients after curative surgery. We demonstrated the cutoff of 7th UICC N stage was similar to that produced from the cut-point survival analysis. The 7th UICC N stage appears to provide a reliable prognostic category of MLNC of gastric cancer than the 5th/6th UICC N stage, and it is the efficiently prognostic indicator of gastric cancer after curative surgery.