ABSTRACT
In the present study, immunohistochemical detection of p53 oncoprotein was performed to determine whether the grade of differentiation and the histologic type of gastric adenocarcinoma, and the degree of atypia accompanied with adenoma can be related to p53 mutation. Paraffin sections of 22 gastric adenomas and 56 gastric adenocarcinomas were examined for the overexpression of p53 oncoprotein with the avidin-biotin peroxidase complex staining procedure. The obtained results were as follows; 1. All the 22 cases of adenomas and 16 cases of well differentated adenocarcinomas showed uniformly negative staining. 2.Seven of 18 cases of moderately differentiated adenocarcinomas(39%), and five of 30 cases of poorly differentiated adenocarcinomas(17%) exhibited p53 protein expression. 3. Three of 29 cases of diffuse type (10%) and 9 of 19 cases of intestinal type(47%) exhibited p53 protein expression. These results suggest that p53 mutation is important in carcinogenesis of the intestinal type of gastric adenocarcinoma, and there is no correlation between the differentiation of gastric adenocarcinoma and the degree of p53 oncoprotein overexpression.