A Comparison Between the Seventh and Sixth Editions of the American Joint Committee on Cancer/International Union Against Classification of Gastric Cancer

Objective: To evaluate the prognostic significance of the seventh edition TNM staging classification for gastric cancer. Background: The seventh edition TNM staging system for gastric cancer was adopted by the American Joint Committee on Cancer/International Union Against Cancer on January 1, 2010, and included major revisions. Methods: The authors analyzed data retrospectively collected on patients with gastric cancer who underwent surgery at the Affiliated Hospital of Qingdao University Medical College between 2000 and 2008. A total of 964 patients with gastric cancer who underwent R0 surgical resection were included. Results: The relative risk (RR) for the seventh edition T classification was found to increase steadily and reasonably compared with the sixth edition. However, the RR for the sixth edition N classification was found to increase steadily and reasonably compared with the seventh edition classification. Cox regression multivariate analysis showed that the sixth edition N classification was superior to the seventh edition N classification as an independent prognostic factor. In survival analysis, the seventh edition TNM classification provided a more detailed classification; however, some subgroups of the seventh edition TNM classification did not demonstrate significantly different survival rates. The combination of the seventh edition T classification and the sixth edition N classification, with ideal RR results, showed significantly different survival rates except for IA and IB. Conclusions: The combination of the seventh edition T classification and the sixth edition N classification seems to provide the optimal prognosis.