ANALYSIS OF P53 EXPRESSION IN PRECANCEROUS AND MALIGNANT GASTRIC-MUCOSA

P53 overexpression, detected by immunohistochemical analysis, has been reported in about 50% of gastric cancers whereas scarce data are avai lable on the p53 oncoprotein in precancerous gastric lesions. This stu dy focused on the p53 expression in gastric cancerous and precancerous lesions. One hundred gastric specimens obtained during endoscopy were analyzed: 14 cases of normal gastric mucosa, 53 of chronic gastritis with intestinal metaplasia and/or dysplasia and 33 gastric tumors. An immunoperoxidase technique and monoclonal anti-p53 antibodies were emp loyed. Eleven out of 31 gastric carcinomas overexpressed p53. No corre lation was observed between p53-positivity and histological type and g rade of tumors. All precancerous lesions were p53-negative. Our result s suggest that p53 overexpression is a relatively late event in gastri c carcinogenesis.