Evaluation of the staging systems for gastric cancer

Background Some staging systems for gastric cancer (GC) have been developed as alternatives to the 6th and 7th TNM staging systems, including the Hybrid, tumor-ratio-metastasis (TRM), and Kiel staging systems. This study evaluated the overall performance of these systems for GC. Methods A total of 540 GC patients undergoing surgical resection were staged using these five systems. Homogeneity, discrimination power, predictive accuracy, and complexity of these systems were compared. Results Multivariate analyses showed that all of 7th pT, pN, and pM classifications were independent factors for GC prognosis (P<0.001 for all). Compared with the other four systems, 7th TNM system had improved stage groups homogeneity (7 of 8 stage groups homogeneous), enhanced discrimination power (4 of 5, 5 of 7, 4 of 7, 3 of 7, and 1 of 4 adjacent stage groups were differentiated by the 6th, 7th TNM, Hybrid, TRM, and Kiel systems, respectively), and better prediction value for GC patients' outcome (AUC=0.801, P<0.001). In addition, the 7th TNM system did not increase the staging complexity (9 groups and 21 subgroups). Conclusions The 7th TNM staging system represents advancement in GC staging system for better prediction of clinical outcomes. J. Surg. Oncol. 2013; 108:93-105. (c) 2013 Wiley Periodicals, Inc.