Ann Surg Treat Res.  2016 Dec;91(6):295-302. 10.4174/astr.2016.91.6.295.

Validation of the 7th AJCC/UICC staging system for gastric cancer and a proposal for a new TNM system based on a prognostic score: a retrospective multicenter study

• Kwon OK
• Kim SW
• Chae HD
• Ryu SW
• Chung HY
• Kim SW
• Lee WK
• Yu W

• KMID: 2360389
• DOI: http://doi.org/10.4174/astr.2016.91.6.295

Abstract

PURPOSE
We validate the 7th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system for gastric cancer and propose a new staging system that reflects the prognostic significances of each of T and N category.
METHODS
Data from 5,957 patients who underwent curative gastrectomies from 2000 to 2007 at 4 university hospitals in Daegu Metropolitan city in Korea were analyzed for the validation of the 7th AJCC/UICC staging system for gastric cancer. The hazard ratios of the respective T and N categories were estimated and converted to weightings and summated to make prognostic score (P-score). Homogeneity and stage grouping were determined according to the P-scores.
RESULTS
In the 7th AJCC/UICC staging system for gastric cancer, poor discrimination was noted between stages IIB and IIIA (P = 0.152). In addition, heterogeneity in stage IIB (P = 0.021) and a small gap in 5-year survival rates (1.7%) between stages IA and IB were noted. A new proposed staging system was generated on the basis of P-scores and demonstrated more discrimination between stages and more homogeneity within stages. The new staging system reflects the different prognostic impacts of N3a and N3b.
CONCLUSION
Several controversial issues of the 7th AJCC/UICC staging system for gastric cancer were reconfirmed in the present analysis. The TNM system based on P-score appears to be more scientifically accurate than the 7th AJCC/UICC staging system for gastric cancer.

Keyword

TNM classification; Stomach neoplasms

MeSH Terms

Daegu
Discrimination (Psychology)
Gastrectomy
Hospitals, University
Humans
Joints
Korea
Population Characteristics
Retrospective Studies*
Stomach Neoplasms*
Survival Rate

Figure

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  Fig. 1 Survival distributions according to T (A) and N (B) categories of the 7th American Joint Committee on Cancer/Union for International Cancer Control staging system.

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  Fig. 2 Survival distributions according to the 7th American Joint Committee on Cancer/Union for International Cancer Control staging system for gastric cancer.

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  Fig. 3 Survival distributions according to the final version of the proposed staging system composed of seven stages.

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