Assessment of the 8th edition of TNM staging system for gastric cancer: the results from the SEER and a single-institution database

Aim: To investigate whether the 8th edition of Tumor, Node, Metastasis (TNM) staging could properly evaluate the prognosis of gastric cancer patients. Methods: The prognostic performance between the 7th and 8th edition of TNM staging was compared and clinicopathologic features were analyzed. Results: The stage shifts in the 8th edition staging resulted in the increased numbers of stage IIIA patients and decreased numbers of stage IIB, stage IIIB and stage IIIC patients. Compared with the previous edition, the 8th edition of TNM staging provided a better prognostic stratification for stage III patients. However, whether it is reasonable to incorporate T4aN2, T4aN3a and T4bN3b into stage IIIA, stage IIIB and stage IIIC respectively, which still need further validation. Conclusion: Despite the obvious superiority, several deficiencies may still exist in the new edition staging. To better provide prognostic information and therapeutic guidance for gastric cancer patients, the TNM staging system should be further improved in the future.