The first 2 authors contributed equally to this article.
The superiority of the seventh edition of the TNM classification depends on the overall survival of the patient cohort
Comparative analysis of the sixth and seventh TNM editions in patients with gastric cancer from Japan and the United Kingdom
Article first published online: 21 DEC 2012
Copyright © 2012 American Cancer Society
Volume 119, Issue 7, pages 1330–1337, 1 April 2013
How to Cite
Hayashi, T., Yoshikawa, T., Bonam, K., Sue-Ling, H. M., Taguri, M., Morita, S., Tsuburaya, A., Hayden, J. D. and Grabsch, H. I. (2013), The superiority of the seventh edition of the TNM classification depends on the overall survival of the patient cohort. Cancer, 119: 1330–1337. doi: 10.1002/cncr.27928
- Issue published online: 18 MAR 2013
- Article first published online: 21 DEC 2012
- Manuscript Accepted: 12 OCT 2012
- Manuscript Revised: 10 OCT 2012
- Manuscript Received: 25 JUL 2012
- gastric cancer;
- seventh edition TNM classification;
- sixth edition TNM classification;
- discriminatory ability;
- United Kingdom;
The objective of this study was to investigate whether the seventh edition of the American Joint Committee on Cancer/International Union Against Cancer TNM classification (TNM7) had superior discriminatory ability over the sixth edition of the TNM classification (TNM6) in patients with gastric cancer regardless of their country of origin.
In total, 538 patients from the Kanagawa Cancer Center Hospital (Yokohama, Japan) (KCCH) and 519 patients from the Leeds Teaching Hospitals National Health Service Trust (Leeds, United Kingdom) (LTHT) who underwent surgery for gastric cancer were selected. Overall survival was used for statistical analysis. Hazard ratios (HRs) were estimated with disease stage as a continuous variable to evaluate the discriminatory ability of the TNM stage groups. The estimates of log HRs (logHRs) for the TNM6 and the TNM7 stage groups were compared.
In the KCCH cohort, 82 patients (15%) were upstaged, and 26 patients (5%) were downstaged between TNM6 and TNM7 compared with 253 patients (49%) and 53 patients (10%), respectively, in the LTHT cohort. The logHRs for a 1-stage increase within TNM6 and TNM7 were 1.06 and 1.16, respectively, in the KCCH cohort and 0.57 and 0.79, respectively, in the LTHT cohort. The differences in logHRs between TNM6 and TNM7 were significant in each cohort (KCCH: logHR, 0.11; P = .024; LTHT: logHR, 0.21; P = .0002) and between the 2 cohorts.
TNM7 had superior discriminatory ability compared with TNM6 in both cohorts. The improved ability to discriminate patients with different survival probability when using TNM7 was greater in the LTHT cohort. The current findings indicated that the discriminatory ability of the TNM stage groups may depend on the baseline survival characteristics of the patient cohort. Cancer 2013. © 2013 American Cancer Society.