Prognostic Value of the 7th AJCC/UICC TNM Classification of Noncardia Gastric Cancer

Abstract

OBJECTIVE: To conduct a retrospective evaluation of the 7th-TNM classification of gastric cancer (GC) on a prospectively collected database. BACKGROUND: The recent TNM introduced relevant changes to GC classification. METHODS: Data regarding 2090 consecutive patients with noncardia GC operated upon between 1991 and 2005 at 5 specialized centers were considered. The application of the new TNM was simulated, and its prognostic value was estimated. RESULTS: Relevant changes in stage distribution between 6th and 7th TNM were observed, mainly regarding the shift of a large proportion of cases from stages IB to IIA and from IIIA and IV to stages IIIB and IIIC. Cancer-related 10-year survival probability was 53% ± 1%. Different survival rates between new T (T2 vs. T3, P < 0.001) and N categories (N1 vs. N2, P < 0.001) were observed. Survival rate of N3a subgroup (7-15 involved lymph nodes) was significantly better than N3b (>15 involved lymph nodes; P < 0.001). Stages IB and IIA of the 7th TNM showed similar prognosis, whereas significant differences were observed among all other subgroups. The analysis of TNM categories within 7th TNM stages revealed nonhomogeneous survival rates in stages IIB, IIIB, and IV. CONCLUSIONS: The 7th AJCC/UICC TNM classification of noncardia GC identifies subgroups of patients with different prognosis. Stage distribution and stage-related survival changed notably from the 6th edition. Some improvements may be suggested from our data, with special reference to a higher prognostic weight of N status and the separation of N3a and N3b categories for stage grouping.