Validation of the updated 7th edition AJCC TNM staging criteria for gastric adenocarcinoma

Abstract

Introduction: The recently published 7th edition of the American Joint Committee on Cancer (AJCC) TNM staging criteria for gastric adenocarcinoma contains important revisions to T and N classifications, as well as overall stage grouping. Our goal was to validate the new staging system using a cancer registry.

Methods: Retrospective review of gastric cancer patients from Surveillance, Epidemiology, and End Results (SEER) registry data (2004-2007). Patients were staged according to both 6th and 7th edition criteria, and 3-year disease-specific survival was compared.

Results: Thirteen thousand five hundred forty-seven patients with gastric adenocarcinoma were identified with complete staging information. When using 7th edition criteria, there was an increase in the number of patients classified as stage III (23% vs. 13%), and a decrease in patients classified as stage IV (47% vs. 53%). Statistically significant differences in 3-year disease-specific survival were observed for all T and N categories and re-staging the same population according to the 7th edition criteria improved survival discrimination. Multivariate analysis revealed statistically significant differences in survival and linear progression of hazard ratios for each stage grouping.

Conclusions: The 7th edition AJCC staging criteria for gastric adenocarcinoma demonstrate better survival discrimination and risk stratification than previous criteria.