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Validation of the seventh edition of the American Joint Committee on cancer tumor node‐staging system in patients with colorectal carcinoma in comparison with sixth classification
Author(s) -
Park Jun Seok,
Choi GyuSeog,
Hasegawa Suguru,
Sakai Yoshiharu,
Huh Jung Wook,
Kim Hyeong Rok,
Kwak Sang Gyu
Publication year - 2012
Publication title -
journal of surgical oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.201
H-Index - 111
eISSN - 1096-9098
pISSN - 0022-4790
DOI - 10.1002/jso.23117
Subject(s) - medicine , stage (stratigraphy) , colorectal cancer , staging system , tnm staging system , adenocarcinoma , cancer staging , retrospective cohort study , overall survival , oncology , survival analysis , general surgery , cancer , surgery , paleontology , biology
Background The aim of this study was to compare survival rates assessed by the seventh‐staging system with those by the sixth classification. Methods This was a retrospective study of 3,377 patients who underwent surgery for colorectal adenocarcinoma from three university hospitals. The overall survival (OS) and cancer‐specific survival (CSS) rates were compared between patients whose stages according to the seventh‐staging system remained the same and patients whose stages migrated, and between subgroups within each new stage (homogeneity analysis). Results In seventh edition, the 5‐year OS and CSS rates of patients with T3n2 tumor were significantly greater in the downstaged patients (T3N2a) than in other patients (T3N2b) (OS, P = 0.010; CSS, P = 0.009). The 5‐year survival rates for patients with T4a and T4b sub‐classifications according to the seventh edition did not differ from those in patients with T4N0‐1. Homogeneity analysis of subgroups classified using the new system showed that some subgroups of stage IIIB (T3N2a/T4aN1) had poorer survival rates compared with patients in other sub‐categories in the same stage IIIB ( P < 0.001). Conclusion Overall, the seventh edition provides a more detailed classification of the prognosis than the old system. However, further study would be warranted to evaluate the validity of sub‐classification in seventh TNM‐staging system, especially for T4a‐b and T3N2a tumors. J. Surg. Oncol. 2012; 106:674–679. © 2012 Wiley Periodicals, Inc.