Histogenesis of the gastric differentiated adenocarcinoma-expression of oncogene protein products and mucin histochemistry in minute gastric cancer

Examination of the immuno-overexpression for myc, ras, c-erbB-2 and p53 and the mucin histochemistry of the gastric adenocarcinoma cells at the earlier stages were performed using 12 lesions of the well differentiated tubular adenocarcinomas, less than 1 mm in greatest dimension (G-ade-1), from the pyloric gland or the intermediate area of the surgically resected stomach. The G-ade-1 had a high frequency of expression of oncogene myc (58%) and of the cancer suppressor gene p53 (83%), while almost no expression of ras or c-erbB-2 was observed. All lesions of G-ade-1 were positive for acid mucin staining, and 8/12 lesions (67%) also for sulfomucin, in 4/12 lesions (33%) gastric native mucin was observed. The adjacent mucosa to all G-ade-1 lesions in this study showed chronic gastritis with incomplete intestinal metaplasia. These results suggested that the human gastric differentiated adenocarcinoma developed accompanying the abnormal expression of myc and p53 with reference to intestinal metaplasia, and that these carcinoma cells always had acid mucin, often the colonic native mucin as sulfomucin, and also sometimes gastric native mucin in the earlier stages.