J Korean Surg Soc.  2010 Sep;79(3):202-206.

The Comparison between 6th and 7th UICC/AJCC N Stage for Prognostic Significance in Gastric Cancer

• Kim JH
• Kim CW
• Choi NK
• Kwak JH
• Choi KM
• Jang HJ
• Han MS
• Lee SJ
• Oh HS
• Choi JS

Abstract

PURPOSE
The 7th edition UICC/AJCC TNM classification for gastric cancer has several changes from the previous edition. Especially, the classification of the number of lymph node metastases (LNM) is reorganized. According to the new TNM system, N stage was categorized to N0 (no LNM), N1 (1~2 LNM), N2 (3~6 LNM), N3 (7 or more LNM). The aim of our study was to compare the prognostic significance of the new (7th) UICC/AJCC N stage with the old (6th).
METHODS
From 2000 to 2005 a total of 425 patients who underwent curative resections with D2 and with 15 or more lymph nodes retrieved were studied retrospectively.
RESULTS
According to the 7th UICC/AJCC N stage, the 5-year cumulative survival rates (5YSR) of N0, N1, N2, N3 were 96.0%, 79.2%, 58.5% and 24.3%, respectively (P<0.001). Using univariate analysis, the N stage of 7th and 6th UICC/AJCC TNM classification, 7th UICC/AJCC T stage, differentiation of tumor, type of gastrectomy (subtotal and total gastrectomy), size of primary tumor (< or =5, 5<< or =10, 10<) were associated with 5YSR. However, Cox regression multivariate analysis showed the 7th UICC/AJCC N stage to bean independent factor for predicting the 5YSR instead of the 6th UICC/AJCC N stage (P<0.001, hazard ratio (HR) 1.859, 95% confidence interval (CI) 1.576~2.194), including depth of tumor invasion (P<0.001, HR 1.673, 95% CI 1.351~2.073).
CONCLUSION
The new (7th) UICC/AJCC N stage is a more reliable prognostic factor of gastric cancer than the old (6th) N stage.

Keyword

6th UICC/AJCC N stage; 7th UICC/AJCC N stage

MeSH Terms

Gastrectomy
Humans
Lymph Nodes
Multivariate Analysis
Neoplasm Metastasis
Retrospective Studies
Stomach Neoplasms
Survival Rate

Figure

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  Fig. 1 Disease-specific survival for patients with gastric cancer following curative resection according to the 6th UICC/AJCC N stage.

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  Fig. 2 Disease-specific survival for patients with gastric cancer following curative resection according to the 7th UICC/AJCC N stage.

Reference

1. Sobin L, Gospodarowicz M, Wittekind C. International Union Against Cancer. TNM Classification of Malignant Tumours. 2009. 7th ed. New York: Wiley-Blackwell.

2. Edge SB, Byrd DR, Compton CC, Fritz AG, Greene FL, Trotti A. AJCC Cancer Staging Manual. 2010. 7th ed. New York: Springer.

3. Hermanek P, Sobin LH. International Union Against Cancer. TNM Classification of Malignant Tumours. 1987. 4th ed. Berlin: Springer.

4. Sobin LH, Wittekind C. International Union Against Cancer. TNM Classification of Malignant Tumours. 1997. 5th ed. New York: Wiley-Liss.

5. Greene FL, Page AL, Fleming ID, Fritz A, Balch CM, Haller DG, et al. American Joint Committee on Cancer. American Cancer Society. AJCC Cancer Staging Manual. 2002. 6th ed. New York: Springer.

6. Yoo CH, Noh SH, Kim YI, Min JS. Comparison of prognostic significance of nodal staging between old (4th edition) and new (5th edition) UICC TNM classification for gastric carcinoma. World J Surg. 1999. 23:492–498.

7. Ikeguchi M, Murakami D, Kanaji S, Ohro S, Maeta Y, Yamaguchi K, et al. Lymph node metastasis of gastric cancer: comparison of Union International Contra Cancer and Japanese systems. ANZ J Surg. 2004. 74:852–854.

8. D'Ugo D, Pacelli F, Persiani R, Pende V, Ianni A, Papa V, et al. Impact of the latest TNM classification for gastric cancer: retrospective analysis on 94 D2 gastrectomies. World J Surg. 2002. 26:672–677.

9. Hayashi H, Ochiai T, Suzuki T, Shimada H, Hori S, Takeda A, et al. Superiority of a new UICC-TNM staging system for gastric carcinoma. Surgery. 2000. 127:129–135.

10. Huang B, Zheng X, Wang Z, Wang M, Dong Y, Zhao B, et al. Prognostic significance of the number of metastatic lymph nodes: is UICC/TNM node classification perfectly suitable for early gastric cancer? Ann Surg Oncol. 2009. 16:61–67.

11. Gunji Y, Suzuki T, Hori S, Hayashi H, Matsubara H, Shimada H, et al. Prognostic significance of the number of metastatic lymph nodes in early gastric cancer. Dig Surg. 2003. 20:148–153.

12. Park DJ, Kong SH, Lee HJ, Kim WH, Yang HK, Lee KU, et al. Subclassification of pT2 gastric adenocarcinoma according to depth of invasion (pT2a vs pT2b) and lymph node status (pN). Surgery. 2007. 141:757–763.

13. Lu Y, Liu C, Zhang R, Li H, Lu P, Jin F, et al. Prognostic significance of subclassification of pT2 gastric cancer: a retrospective study of 847 patients. Surg Oncol. 2008. 17:317–322.

14. Choi BH, Kim JH, Kwak JH, Jang HJ, Han MS. The analysis of clinical characteristics of pT2a and pT2b gastric cancer. J Korean Surg Soc. 2009. 77:257–261.

15. Feinstein AR, Sosin DM, Wells CK. The Will Rogers phenomenon. Stage migration and new diagnostic techniques as a source of misleading statistics for survival in cancer. N Engl J Med. 1985. 312:1604–1608.

16. Roder JD, Bonenkamp JJ, Craven J, van de Velde CJ, Sasako M, Bottcher K, et al. Lymphadenectomy for gastric cancer in clinical trials: update. World J Surg. 1995. 19:546–553.

17. Wagner PK, Ramaswamy A, Ruschoff J, Schmitz-Moormann P, Rothmund M. Lymph node counts in the upper abdomen: anatomical basis for lymphadenectomy in gastric cancer. Br J Surg. 1991. 78:825–827.