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Open Access 01-07-2018 | Original Article
The 8th edition of the American Joint Committee on Cancer tumor-node-metastasis staging system for gastric cancer is superior to the 7th edition: results from a Chinese mono-institutional study of 1663 patients
Published in: Gastric Cancer | Issue 4/2018
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Background
We investigated the superiority of the 8th edition of the tumor-node-metastasis (TNM) system for patients in China with gastric cancer.
Methods
The survival outcomes of 1663 patients with gastric cancer undergoing radical resection were analyzed.
Results
In the 8th edition system, homogeneous 5-year survival rates among different pathological TNM (pTNM) categories belonging to the same stage were observed. However, in the 7th edition system, the differences of 5-year survival rate among pTNM categories belonging to the same stage were observed in stages IIB (P = 0.010), IIIB (P = 0.004), and IIIC (P < 0.001). For patients in the pT1-3 (P < 0.001) and pT4a (P < 0.001) categories, there were significant differences in survival between patients in the pN3a and pN3b categories. Furthermore, partial cases (pT4bN0M0/T4aN2M0) of stage IIIB were downstaged to stage IIIA in the 8th edition system, and the 5-year survival rate of these patients was significantly better than that of patients in stage IIIB in the 8th edition system. Similarly, the 5-year survival rate of patients in p4bN2M0/T4aN3aM0 downstaged from stage IIIC to IIIB was significantly better than that of patients in stage IIIC. Compared with the 7th edition system, the 8th edition system had a higher likelihood ratio and linear trend chi-squared score and a smaller Akaike information criteria value.
Conclusions
The 8th edition system is superior to the 7th edition system in terms of homogeneity, discriminatory ability, and monotonicity of gradients for Chinese patients with gastric cancer.