[The Comparison between 6th and 7th International Union Against Cancer/American Joint Committee on Cancer Classification for Survival Prognosis of Gastric Cancer].

BACKGROUND/AIMS: The tumor-node-metastasis (TNM) staging is an useful system to assess the prognosis of any solid cancer. As new TNM staging classification of 7th stomach cancer was revised in 2009, we evaluated the prognostic predictability of the 7th International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) TNM classification compared to 6th UICC/AJCC TNM classification in gastric cancer. METHODS: From January 2000 to December 2009, 5-year survival rates of 266 patients with gastric cancer were calculated by the 6th and 7th UICC/AJCC TNM classification. RESULTS: Using the 7th UICC/AJCC TNM classification, there was no significant difference in the 5-year cumulative survival rates (5 YSR) between stage IIA and IIB, IIB and IIIA, and IIIA and IIIB (70% vs. 71%, p=0.530; 71% vs. 80%, p=0.703; 80% vs. 75%, p=0.576, respectively) though significant differences of the survival rates were observed among stages of 6th edition. Using T stage of 7th edition, 5 YSR was not different between T2 and T3 (86% vs. 82%, p=0.655). Using N stage of 7th edition, 5 YSR were not different between N1 and N2, N3a and N3b (79% vs. 81%, p=0.506; 41% vs. 17%, p=0.895, respectively). CONCLUSIONS: The 7th UICC/AJCC TNM classification had poor prognostic predictability in gastric cancer compared to the 6th edition.