Figure 1.

Definitions, patients’ distribution, and stage migrations in AJCC 7^th and AJCC 8^th TNM staging systems. A: AJCC 7^th TNM staging system. B: AJCC 8^th TNM staging system. According to the definition, there were no changes in stage IA, IB, IIA, and IV from AJCC 7^th staging system to 8^th staging system. Stage migrations were occurred in subgroups highlighted in the blue dashed rectangle, including stage IIB, IIIA, IIIB, and IIIC. Exact patients number was also shown. On the whole, the percentage of patients with stage IIIA, IIIB, and IIIC was 15.6%, 21.7%, and 21.5% in AJCC 7^th staging system, and changed to 34.3%, 16.5%, and 8.0% in AJCC 8^th staging system, respectively. Purple-framed categories were upstaged GC cases. Blue-framed categories were downstaged GC cases. Green-framed categories were unchanged GC cases.