Prognostic impact of the number of all dissected and negative lymph nodes in gastric cancer after curative distal gastrectomy

Abstract

To investigate the prognostic impacts of number of all dissected and negative lymph nodes (LNs) in gastric cancer after curative distal gastrectomy. This study involved 634 patients with gastric cancer, who underwent curative resection with distal gastrectomy from January 1995 to November 2004. Long-term surgical outcomes and associations between dissected LN counts or negative LN counts with the 5-year survival rate were investigated. In this group, 591 patients (93.2%) was followed-up for 5 - 14 years, the median survival was 62.0 months. The 5-year survival of the entire cohort was 57.6%. The number of negative LNs was positively correlated with the retrieved nodes count on the Pearson's correlation test (P < 0.05). Cox regression analysis showed that depth of tumor invasion, LN involvement, negative LN count and dissected LN count were independent predictors of survival (P < 0.05). Among patients with comparable TNM ranks, the overall survival rate was significantly different among patients with different dissected LN counts or negative LN counts. For each 10 extra LNs added to the total LN count, the calculated overall survival rate increased by: 14.2% (stage I), 20.5% (stage II), 17.5% (stage III), 10.9% (stage IV) and 13.1% (entire cohort). While, for each 10 extra negative LNs added to negative LN counts, the overall survival rate increased by: 20.1% (stage I), 18.8% (stage II), 18.4% (stage III), 18.0% (stage IV) and 19.2% (entire cohort). The number of dissected LNs and negative LNs are independent predictors of survival for gastric cancer. More LNs should be resected in patients receiving curative distal gastrectomy to improve prognosis.