Width of serosal invasion and prognosis in advanced human gastric cancer with special reference to the mode of tumor invasion.

We studied the influence of the width of serosal invasion on the prognosis, in relation to the mode of invasion, in 142 patients who had curative resection for gastric carcinoma that invaded beyond the muscularis propria. The mode of invasion was classified into infiltrative and expanding types. Average diameter of tumor at the serosal or subserosal layer for the infiltrative type was 4.2 +/- 3.2 cm, a value significantly greater than that of 2.5 +/- 2.0 cm for the expanding type (P less than 0.01). The 5-year survival rate of patients with the infiltrative type carcinoma was significantly lower (36.8%) than that with the expanding type carcinoma (50.0%) (P less than 0.05). In the infiltrative type, the survival time of patients with a serosal invasion exceeding 2 cm was significantly shorter than when the serosal invasion was less than 2 cm (P less than 0.05). In the expanding type, however, the prognosis was good until the width of serosal invasion extended to 4 cm or greater. The difference in survival according to the width of serosal invasion did not always depend on the incidence of positive lymph nodes in both types of carcinomas. Therefore, influence of the width of serosal invasion on the prognosis for advanced gastric carcinomas differs between infiltrative and expanding types.