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.