Most important lymph node information in gastric cancer: Multivariate prognostic study

Background: In gastric cancer, the level and number of lymph node metastases is useful for predicting survival, and there are several staging systems for lymph node metastasis. The aim of this study was to compare the several lymph node classifications and to clarify the most important lymph node information associated with prognosis using multivariate analysis. Methods: A total of 106 patients with histologically node-positive gastric cancer treated by radical gastrectomy and extended lymph node dissection (D2, D3) were studied. The level of lymph node metastasis was categorized simply as Level I nodes (perigastric, No.1-6), Level II nodes (intermediate, No.7-9), and Level III nodes (distant, No.10-16), irrespective of the tumor location. The Level II nodes included lymph nodes along the left gastric artery, common hepatic artery, and celiac trunk. Results: Overall 5-year survival rate was 51%. Univariate analysis showed that 5-year survival rate was significantly influenced by the level of positive nodes (P < .01), total number of positive nodes (P < .01), number of positive Level I nodes (P < .01), and number of positive Level II nodes (P < .01), in addition to the tumor location (P < .05), tumor size (P < .05), gross type (P < .01), and depth of wall invasion (P < .01). Of these, independent prognostic factors associated with 5-year survival rate were the number of positive Level LI nodes (0-1 vs. greater than or equal to 2) (62% vs. 19%, P < .01) and the depth of wall invasion (within vs. beyond muscularis) (79% vs. 43%, P < .01). Conclusions: Among several staging systems for lymph node metastases, the number of positive Level II nodes provided the most powerful prognostic information in patients with node-positive gastric cancer. When there were two or more metastases in the Level II nodes, prognosis was poor even after D2, or D3, gastrectomy.