Validation of the seventh edition of the American Joint Committee on Cancer TNM staging system for gastric cancer.
BACKGROUND
The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer was published in 2010 and included major revisions. The aim of the current study was to evaluate the validity of the seventh edition TNM classification for gastric cancer based on an Asian population.


METHODS
A total of 2916 gastric cancer patients who underwent R0 surgical resection from 1989 through 2008 in a single institute were included, and were analyzed according to the seventh edition of the TNM classification for validation.


RESULTS
When adjusted using the seventh edition of the TNM classification, upstaging was observed in 771 patients (26.4%) and downstaging was observed in 178 patients (6.1%) compared with the sixth edition of the TNM classification. The relative risk (RR) of seventh edition pT classification was found to be increased with regular intensity compared with the sixth edition pT classification. The RR of seventh edition pN classification was found to be increased with irregular intensity compared with the sixth edition pN classification. In survival analysis, there were significant differences noted for each stage of disease, but only a marginal difference was demonstrated between stage IA and stage IB (P = .049). In the hybrid TNM classification, which combines the seventh edition pT classification and the sixth edition pN classification, both pT and pN classifications demonstrated a more ideal distribution of the RR, and 5-year survival rates also showed a significant difference for each stage (P <.01).


CONCLUSIONS
The seventh edition of the TNM classification was considered valid based on the results of the current study. However, the hybrid TNM classification, comprised of a combination of the seventh edition pT classification and sixth edition pN classification, should be considered for the next edition.
Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Hun
H
Jung
Han Hong
HH
Lee
Kyo Young
KY
Song
Hae Myung
HM
Jeon
Cho Hyun
CH
Park
D044466:Asian People; D006801:Humans; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology
gastric cancer; hybrid TNM staging system; seventh edition American Joint Committee on Cancer TNM staging system; validation