Survival benefit of extended D2 lymphadenectomy in gastric cancer with involvement of second level lymph nodes: A longitudinal multicenter study

Background: The survival benefit of extended lymphadenectomy in the surgical treatment of gastric cancer is still being debated. The aim of this longitudinal multicenter study was to evaluate long-term survival in a group of patients with involvement of second level lymph nodes, which would not have been removed in the case of a limited lymphadenectomy. Results were compared with those in patients with involvement of first level lymph nodes. Methods: Between 1991 and 1997, 451 patients with primary gastric cancer underwent curative resection with extended lymphadenectomy at three surgical departments in Italy according to the rules of the Japanese Research Society for Gastric Cancer. Results: In 451 cases treated by extended lymphadenectomy, morbidity and mortality rates were 17.1 % and 2%, respectively. In 126 patients (27.9%) (group A), metastases were found in lymph node stations 7 to 12; 109 patients (24.2%) had metastases confined to the first level (group B). Lymph node stations 7 and 8 showed the highest incidence of metastases in the second level (17.1% and 12.4%, respectively). A significant difference in 5-year survival was observed between group A and group B (32% vs. 54%; P = .0005). This difference disappeared when cases were stratified according to the number of positive lymph nodes. By multivariate analysis, only the number of positive lymph nodes (relative risk, 1.8; P < .0001) and the depth of invasion (relative risk, 2.1; P < .0001), but not the level of involved nodes, showed to be independent predictors of poor prognosis. Conclusions: Japanese-type extended lymphadenectomy yields low morbidity and mortality rates if performed in specialized centers. This procedure could provide a good probability of long-term survival, even for patients with involvement of regional lymph nodes.