[Expression of p53 in gallbladder carcinoma and in dysplastic and metaplastic lesions of the surrounding mucosa].

We studied the expression of p53 in 80 gallbladder carcinomas, 43 peritumoral mucosae, 5 adenomas and 20 mucosae of non tumoral gallbladders. Gallbladder cancers were classified according to WHO criteria. We found p53 overexpression in 51 out of the 80 gallbladder cancers (64%). p53 expression was variable in different histologic subtypes: 100% of intestinal type, 66% of papillary type, 83% of adenosquamous carcinomas and 66% of giant cells cancers showed immunoreactive cells. In well and moderately differentiated conventional gallbladder adenocarcinomas we found 60% of positive cases, while, among poorly differentiated conventional cancers, 83% were immunoreactive. All mucinous adenocarcinomas were p53-negative. In peritumoral dysplastic mucosae, p53 was expressed in 23 out 38 cases (60%), 22 (96%) of which were associated to a p53-positive adenocarcinoma. On the contrary, only 5 of the 15 p53-negative dysplastic lesions (33%) were associated to an p53-immunoreactive adenocarcinoma. Metaplastic lesions, of gastric and intestinal type, and adenomas were completely p53-negative. In conclusion, our data suggest that p53 expression is an early event, frequently involved in gallbladder carcinogenesis, and related to different histologic subtypes of gallbladder adenocarcinomas.