Characteristics of Gastric Cancer Invading to the Proper Muscle Layer--with Special Reference to Mortality and Cause of Death--

A total of 2,608 patients with gastric cancer received curativeor palliative resection in the surgical department of the NationalCancer Center Hospital during the 13-year period from 1968 to1980. Of these, 261 patients with gastric cancer invading tothe proper muscle layer (pm cancer) were studied. The incidence of pm cancer was 10.0% (261/2,608). Annual incidenceshowed a tendency of a little increase as compared with thepronounced increase in early cancer in recent years. Male patientscomprised 67% of the total. Sixty- to 69-yr-old patients constituted28.7%. This cancer occurred more frequently in the lower portionand the lesser curvature of the stomach. The type looking likeearly cancer comprised 38.3% (100/261). Histologically, undifferentiatedtypes constituted 50% (131/261) and differentiated types comprised44% (117/261). There were nine patients with distant metastasisdespite the fact that the invasion was limited to the pm layer. Eighty-one (31%) of the 261 patients had died by November 1984.However, the survival period was longer than that for advancedcancer invading to the serosal layer. Concerning the cause ofdeath, 48 (59.2%) of the 81 patients died of recurrent cancerand 27 (33.3%) died of nonmalignant disease. Death caused byhematogenous metastasis, especially liver metastasis, was themost characteristic. A close relationship was not found betweenthe mode of invasion to the pm layer and mortality.