Indications of a minimized scope of lymphadenectomy for submucosal gastric cancer

Background A recent trend for less invasive surgery has increased consideration for a minimized scope of lymphadenectomy for submucosal cancer; however, feasibility criteria have not been precisely established. Methods Patterns and sites of nodal involvement were retrospectively investigated in 294 patients with solitary submucosal gastric cancer in association with other clinicopathologic characteristics, including pre- and intraoperative evaluations of cancer depth (cT) and nodal involvement (cN). Results Among the early (cT1) and node-negative (cN0) cancer, intestinal (≤1.5 cm) and diffuse types (<-1.0 cm) of submucosal cancer showed low incidences of nodal involvement (3%) confined to the first tier. When the cancer exceeded these cutoff diameters, positive nodes of the second tier were confined to three priority stations (left gastric, common hepatic, and celiac arteries) at an incidence of 2.3%. Perigastric and preferential dissection of these three node stations (modified D2 dissection) showed survival benefits identical to those of a conventional D2 dissection. Conclusions When submucosal cancer is evaluated as cT1cN0, a virtually sufficient minimized scope of lymphadenectomy is a D1 dissection for that within the cutoff diameter and a modified D2 dissection for that exceeding the cutoff diameter. These two types of dissection can even cover the infrequently observed node-positive stations and can realize no residual disease at surgery.