Hepatitis B- and hepatitis C-related hepatocellular carcinomas in the United States: similarities and differences.

BACKGROUND

Hepatitis B and Hepatitis C (HBV and HCV) infections are both major causes of hepatocellular carcinoma (HCC). However, HCC caused by each of these two viruses has unique characteristics that should be studied independently to that of another one. While HBV- and HCV-related HCCs share similar host and environmental risk factors such as male gender, age above 50 years old, family history of HCC, cirrhosis, obesity, and concomitant alcohol/tobacco use, they differ in their viral risk factors.

METHODS

The actual level of HBV DNA, the presence of HBV e antigen (HBeAg), and mutations in the viral genome are important predisposing factors to HCC development in HBV, whereas in HCV, viremia of any amount denotes an elevated risk. HBV and HCV also differ in their mechanisms of carcinogenesis. For example, HBV can integrate into the host genome and induce many different genetic alterations/mutations. Ultimately, though, both viruses act on similar pathways to produce HCC.

RESULTS

HBV and HCV are often transmitted differently - vertically (HBV) and horizontally (HCV), which may play a role in their distinct clinical presentations: HBV patients are younger and more frequently have larger/ bilobar tumors as opposed to HCV patients, who have worse liver function on diagnosis of HCC. Even the way they respond to treatment seems to be different. HBV-related HCC patients tend to progress faster after sorafenib treatments.

CONCLUSIONS

Future studies should investigate the ways in which these differences between HBV- and HCV-related HCC can translate into more tailored treatment strategies for each etiology of HCC in order to improve outcomes of both.