P53 AND C-ERBB-2 PROTEIN EXPRESSION IN ADENOCARCINOMAS AND EPITHELIALDYSPLASIAS OF THE GALL-BLADDER

In this study we investigated immunohistochemically the expression of p53 and c-erbB-2 proteins in 30 gall bladder adenocarcinomas, one carc inoma in situ, eight gall bladder epithelial dysplasias, and four case s of chronic cholecystitis. p53 expression could be found in 14 (47 pe r cent) adenocarcinomas and in two out of eight epithelial dysplasias. There were significantly more p53-positive grade II-III tumours than grade I tumours (P=0.032 according to Fisher's exact probability test) . c-erbB-2 expression was found in three (10 per cent) adenocarcinomas , but all dysplasias were c-erbB-2-negative. All three c-erbB-2-positi ve cases were also p53-positive. The results indicate that p53 mutatio ns and c-erbB-2 gene alterations play a role in the neoplastic transfo rmation of gall bladder epithelial cells. Co-expression of p53 and c-e rbB-2 suggests that alterations of these genes might act in concert in the neoplastic transformation. The occurrence of p53 expression in ga ll bladder dysplasias suggests that p53 mutations could be an early ev ent in the evolution of some gall bladder carcinomas, as has been sugg ested for some other types of tumours, such as lung squamous cell carc inomas.