GENETIC-HETEROGENEITY OF HEPATOCELLULAR-CARCINOMA

We studied 80 hepatocellular carcinomas from three continents For p53 gene (TP53) mutations and hepatitis B virus (HBV) sequences. p53 mutat ions were frequent in tumors from Mozambique but not in tumors from So uth Africa, China, and Germany. Independent of geographic origin, most tumors were positive for HBV sequences. X gene coding sequences of HB V were detected in 78% of tumors, whereas viral sequences in the surfa ce antigen- and core antigen-encoding regions were present in less tha n 45% of tumors. These observations indicate that hepatocellular carci nomas are genetically heterogeneous. Mozambican-type of hepatocellular carcinomas are characterized by a high incidence of p53 mutations rel ated to aflatoxins. In other tumors, the rarity of p53 mutations combi ned with the frequent presence of viral X gene coding sequences sugges ts a possible interference of HBV with the wild-type p53 function.