EXPRESSION OF MUTANT P53 PROTEIN IN HEPATOCELLULAR-CARCINOMA

p53 mutations are a common genetic finding in hepatocellular carcinoma from areas of high aflatoxin exposure. Recent small studies have show n that p53 gene mutations may be less common in areas with a low preva lence of hepatocellular carcinoma such as Great Britain. The protein p roduct of mutant p53 can be detected immunohistochemically because of its longer half life in comparison with native protein. This study use d a novel monoclonal antibody DO-7, raised against recombinant p53 and effective in routinely processed biopsy specimen tissue, to detect th e mutant protein in a series of 45 cases of hepatocellular carcinoma o ccurring in white subjects resident in the United Kingdom. Focal nucle ar labelling was seen in four cases (9%); surrounding cirrhotic tissue in one of these was negative for p53 expression. This study shows tha t p53 mutations are a rare event in hepatocarcinogenesis in Great Brit ain, an area of low aflatoxin exposure, and supports the concept of ge ographical variations in the cause and pathogenesis of hepatocellular carcinoma.