Influence of Nodal Yields on Staging of Gastric Cancer and on Survival

ABSTRACT

PURPOSE: In the fifth edition of International Union Against Cancer (UICC) TNM, nodal staging for gastric cancer is based on the number of metastatic lymph nodes. Variability in the extent of lymphadenectomy and lymph node retrieval can affect the number of metastatic lymph nodes. In this study, the authors attempted to evaluate the influence of nodal yields on the staging of gastric cancer and survival rates. METHODS: A retrospective study was performed in 4354 consecutive patients with gastric cancer, who had undergone curative resection (R0) with nodal yields of 15 or more from 1986 to 1995. Patients were classified into three groups according to the number of nodes examined patients with nodal yields of 15 or more but less than 30 for group A, 30-39 for group B, and 40 or more for group C. The number of metastatic lymph nodes and the survival rates for each pTNM stage were analyzed for each group. RESULTS: The number of metastatic lymph nodes significantly increased with nodal yields. Greater nodal yields resulted in a higher survival rates with a statistically significant difference between patients with nodal yields of 30 or more, and those with less than 30 in stage IB (p<0.05) and IIIB (p<0.01). CONCLUSION: Our results suggest two possibilities of stage migration and survival benefit according to the difference of nodal yields. Therefore, for minimizing stage migration and maximizing the benefit of survival, at least 30 or more lymphnodes should be resected and examined in gastric cancer surgery.