OVEREXPRESSION OF P53 IN HEPATOCELLULAR CARCINOMAS - A CLINICOPATHOLOGICAL AND PROGNOSTIC CORRELATION

Overexpression of the p53 tumour suppressor gene is one of the most co mmon abnormalities in primary human cancers and appears to be a result of point mutation within a highly conserved region of the gene with s ubsequent encoding for a mutant, more stable protein. In this study, 7 1 surgically resected hepatocellular carcinomas (HCC) were examined to study the expression of the p53 gene, its relation with clinicopathol ogical parameters and its prognostic significance. Using immunohistoch emical detection for mutant p53 protein with monoclonal antibody PAb18 01, p53 overexpression was found in 22 rumours (31%) but in none of th e non-tumorous liver specimens. Overexpression of p53 was more frequen t in tumours with poor cellular differentiation (P = 0.01), in rumours > 5 cm in diameter (P = 0.05), and in those with giant cells present (P = 0.03) and, less significantly, of massive type of Eggel's classif ication (P = 0.06). It did not have any significant correlation with h epatitis B or C status, background liver disease or serum alpha-fetopr otein levels, nor was it related to tumour invasiveness (venous permea tion, direct liver invasion and tumour microsatellite formation). In a ddition, the presence of p53 mutant protein did not influence tumour r ecurrence or patients' survival rates. The data suggested that p53 mut ation in HCC was associated with a later stage of oncogenesis. However , it was not apparently related to tumour invasiveness/aggressiveness and prognosis.