Greater tendency for submucosal invasion in fundic area gastric carcinomas than those arising in the pyloric area.

Variation in tendency of gastric carcinomas for submucosal invasion according to the site of origin in the stomach was investigated. A total of 230 and 790 gastric carcinomas located in the fundic and pyloric areas, respectively, were used to determine rates of invasion (IR) beyond the lamina muscularis mucosae relative to the size and histologic type of lesion. The IR values increased with carcinoma size in both areas. However, carcinomas in the fundic area demonstrated significantly higher IR rates (P less than 0.003) in every size class and for both poorly and well-differentiated lesions. Moreover, whereas small (less than 10 mm) invasive carcinomas were remarkably frequent in the fundic area, large (greater than 81 mm) noninvasive (mucosal) carcinomas were almost exclusively limited to the pyloric area. Thus gastric carcinomas in the fundic area were clearly shown to have a greater tendency to become invasive than those in the pyloric area. This may be related to differences in local anatomical and physiologic conditions.