Does the New UICC/AJCC TNM Staging System (7th Edition) Improve Assessing Prognosis in Gastric Cancer Compared to the Old System (6th Edition)?

ABSTRACT

PURPOSE: We evaluated the efficacy and prognostic predictability of the 7th UICC TNM classification compared to 6th UICC TNM classification in patients with gastric cancer. MATERIALS AND METHODS: Between June 1992 and December 2006, 1,633 patients with gastric cancer who had undergone gastric surgery and who had been analyzed by the 6th UICC method were analyzed using the new 7th UICC system. RESULTS: Significant differences in 5-year survival rates were observed for 7th UICC N0, N1, N2, N3a, and N3b compared to 6th UICC. There were no significant differences in 5-year survival rates between T2 and T3. Distinct survival differences were present between stage III (IIIa, IIIb, and IIIc) and stage IV in 7th UICC. Significant differences in 5-year survival rates were not expected for Ia versus Ib, Ib versus IIa, and IIb versus IIIa. The survival rates for the same stages were not homogeneously differentiated by 7th UICC except for stage IV. CONCLUSION: The 7th UICC classification system is not better able to predict patient survival compared to 6th UICC in patients with gastric cancer, but is better for accurate prognosis of patients with stage IV gastric cancer.