Vascular invasion of early gastric cancer at resection line

Vascular invasion is observed in early gastric cancers (EGCs) as well as advanced gastric cancers. However, there have been no studies assessing adequate surgical margins for EGCs with reference to vascular invasion. A total of 452 EGCs were retrospectively evaluated. Vascular invasion, via lymphatics and/or venous vessels, was examined histologically. The distance from the tumor edge to infiltration was measured when cancer cells extended beyond the tumor through vessels. Vascular invasion was histologically confirmed in 41 EGCs (9.1%). Invasion was in one-fourth (40/166, 24.1%) of submucosal cancers, but in only one (1/286, 0.3%) mucosal cancer. Five EGCs (1.1%) showed infiltration beyond the tumor through the vessels and the maximum distance from the tumor edge to the most distal site of infiltration was 4 mm. In conclusion, a 2 cm surgical margin, as recommended in Japanese surgical textbooks, is adequate for EGCs with reference to vascular invasion.