[pm Gastric cancer and modes of invasion to the pm layer]

Two hundred and eighty-eight cases of gastric cancer, whose deepest layer of cancerous invasion was the tela muscularis propria (pm), were divided into the following 4 types according to modes of invasion to the pm layer: 1) minimal invasion type (45 cases, 16%); 2) localized invasion type (128 cases, 44%); 3) diffuse invasion type (98 cases, 34%), and 4) vascular invasion type (17 cases, 6%). This classification of modes of invasion to the pm layer was useful and reflected the gross findings of cancer, grade of vascular invasion and prognosis quite well.