Appropriate lymph node dissection for early gastric cancer based on lymph node metastases

Background. Lymph node dissection in patients with early gastric cancer is controversial because lymph node metastases are much less common than in advanced cancer. Therefore, routine extensive lymph node dissection with wide resection of the stomach may be excessive, and an appropriate lymph node dissection procedure in patients with early gastric cancer should be established. Methods. Retrospectively, 588 consecutive patients with early gastric cancer were analyzed by univariate and multivariate analysis to predict lymph node metastases with clinicopathologic variables. The sites and rates of lymph node metastases for each tumor location were mapped. Results. In early gastric cancer, depth of invasion was an independent predictive factor of lymph node metastases. In cancer confined to the mucosa, however, tumor diameter was the only predictive factor. In contrast, tumor diameter, macroscopic appearance,and histologic type were not predictive factors in early gastric cancers invading the submucosa. In mucosal cancer, metastasis to lymph nodes was confined to the paragastric lymph nodes on the same side of the stomach as the tumor. In submucosal cancer, the incidence of lymph node metastasis was 2% to 17% in group 1 and 1% to 3% in group 2 lymph nodes. Conclusions. In mucosal cancer, lymph node dissection is unnecessary for tumors measuring less than 30 mm, and limited lymph node dissection with local gastrectomy is appropriate when tumor diameters are 30 mm or greater. In submucosal cancer, gastrectomy with dissection of group 1 and some group 2 lymph nodes should be sufficient to remove all nodal metastases.