P53 EXPRESSION IN HEPATOCELLULAR-CARCINOMA IN A POPULATION IN SINGAPORE WITH ENDEMIC HEPATITIS-B VIRUS-INFECTION

Aims-To study the expression and clinical significance (if any) of p53 protein in hepatocellular carcinomas (HCC) arising in a population wi th endemic hepatitis B virus (HBV) infection. Methods-Immunohistochemi cal staining was performed on formalin fixed, paraffin wax embedded hi stological sections of 46 HCC cases using an antihuman p53 monoclonal antibody; serial sections were also stained for hepatitis B surface an tigen (HBsAg), hepatitis B core antigen (HBcAg) and alpha fetoprotein (AFP). Nuclear p53 staining was assessed according to intensity (absen t, weak or strong) and extent (<5%, 6-25%, 26-50%, and >50%) of positi ve cells. Tissue HBsAg, HBcAg and AFP were recorded as absent or prese nt. Results-The p53 protein was expressed in 35% (16 of 46) of HCCs; t he positive rate in grade III/IV tumours (13 of 31; 42%) was higher th an in grade I/II tumours (three of 15; 20%) but this was not statistic ally significant. HBsAg positive tumours showed almost the same propor tion of p53 staining (11 of 29; 38%) as HBsAg negative ones (five of 1 7; 29%). Conclusions-The p53 protein was expressed in 35% of HCC cases . There was no statistically significant correlation between HBV infec tion and p53 protein expression. Similarly, there was no definite corr elation between p53 positivity and tumour size, histological grade or vascular invasion.