Prognostic significance of level and number of lymph node metastases in patients with gastric cancer

Abstract

Background: To present data that provide some insight into the appropriateness of a nodal grouping category and its relation to survival in patients with gastric cancer.

Methods: We reviewed data of 777 patients with advanced gastric cancer who had undergone curative gastrectomy to investigate the prognostic significance of level and number of lymph node metastases.

Results: The prognosis of patients with gastric cancer was well correlated with the level and number of lymph node metastases. Multivariate analysis indicated that the level and number of lymph node metastases were independent prognostic indicators. Moreover, the number of lymph node metastases was an independent prognostic factor in N1, N2, and N3 patients. The most statistically significant difference in disease-specific survival was observed at a threshold of 11 lymph node metastases, yielding a chi2 value of 42.88, a hazard ratio of 2.523, at a 95% confidence interval of 1.913, 3.329 (P < .0001) by Cox proportional hazard model. On the basis of this result, patients were divided into two groups as follows: marked lymph node metastasis group (number of positive nodes > or =11) and slight lymph node metastasis group (number of positive nodes < or =10). The prognosis of patients with marked lymph node metastasis was statistically significantly worse than that with slight lymph node metastasis in N1, N2, and N3 patients.

Conclusions: Both level and number were indispensable for evaluating lymph node metastasis. Therefore, addition of the number of positive nodes to the N category defined by the Japanese Classification of Gastric Carcinoma may be a useful strategy in the N staging classification in gastric cancer.