Marked genetic similarities between hepatitis B virus-positive and hepatitis C virus-positive hepatocellular carcinomas.

Hepatocellular carcinoma (HCC) is one of the most common neoplasms worldwide. Well-established risk factors include infections with two very different viruses: the DNA virus causing hepatitis B (HBV) and the RNA virus inducing hepatitis C (HCV). In order to determine whether genetic differences exist between HBV- and HCV-induced HCC, 41 HCC samples of known vival status were examined by comparative genomic hybridization (CGH). The analysis revealed frequent deletions of 1p (24%), 4q (39%), 6q (41%), 8p (44%), 9p (24%), 11q (24%), 12q (22%), and 13q (39%), as well as common gains of 1q (46%), 6p+ (20%), 8q+ (41%), 11q (27%), and 17q+ (37%). There was no significant difference in the number and type of chromosomal imbalances between 25 HCV- and 16 HBV-infected tumours. This is consistent with models suggesting that HBV and HCV cause cancer through non-specific inflammatory and regenerative processes, rather than through virus-specific interactions with defined target genes. Chromosomal imbalances were also unrelated to the grade and stage of HCC. This may suggest that most gross genomic alterations occur early during HCC development and that further progression of these tumours may be associated with other types of genetic changes, not detectable by CGH. In summary, these data show that characteristic gross genomic changes occur in HCC, but these alterations at present do not appear to have diagnostic or prognostic applications.