OBJECTIVETo analyze the clinical application value of the 7th edition UICC-AJCC TNM pT classification of gastric cancer.

METHODSThe classification of tumor invasion depth of 874 cases of gastric cancer was determined using the 7th edition UICC-AJCC TNM classification and the relationships of prognosis with clinicopathological factors was compared with that obtained using the 6th edition TNM classification.

RESULTSThe 5-year survival rates according to the 6th edition pT1, pT2, pT3, pT4 were 98.4%, 55.8%, 26.0% and 24.5%, respectively, showing a significant difference among the four substages (P<0.001). The 5-year survival rates according to the 7th edition pT1a, pT1b, pT2, pT3, pT4a, and pT4b were 98.6%, 98.2%, 75.8%, 48.9%, 26.0% and 24.5%, respectively, and there were significant differences in survival time among the six substages (P<0.001). According to the 7th edition TNM classification, for the pT2 and pT3 patients groups, the 5-year survival rates of the 7th edition pN0 (without lymphatic metastasis) were 84.8% and 77.9%, respectively, showing no significant difference between the two survival rates (P=0.204). The 5-year survival rates according to the 7th edition pNx (with lymphatic metastasis) were 66.9% and 37.5%, respectively, and there was a significant difference between the two survival times (P<0.001). In multivariate analysis, the 7th edition pT stage, vascular or lymphatic invasion, the 6th edition pT staging and primary tumor site were independent prognostic factors in patients with gastric cancer (P<0.05), and the relationship of the staging of the 7th version of pT was more close with the prognosis of patients with gastric carcinoma than that of the 6th edition of pT staging system.

CONCLUSIONThe 7th edition UICC-AJCC classification of pT staging of gastric cancer patients has a better prognostic predictive value than the 6th edition.