Difference in incidence of developing hepatocellular carcinoma between hepatitis B virus-and hepatitis C virus-infected patients

BACKGROUND It is generally accepted that the incidence of hepatocellular carcinoma（HCC） in hepatitis C virus（HCV）-associated patients is higher than that in hepatitis B virus（HBV）-associated patients. The reason why this difference in the incidence of HCC occurs in patients with HBV and HCV infections remains unclear. We report the possibility that the contributing power of inflammation, which is the main risk factor for developing HCC, may be different with HBV and HCV infections.AIM To investigate this, we surveyed the hazard ratio of inflammation for HCC development which was identified by serum alanine aminotransferase（ALT） levels between patients with HBV and HCV infections.METHODS The Pub Med database was searched（2001-2021） for studies published in English regarding the incidence of HCC identifying 8924 HBV-and 7376 HCV-infected patients. From these studies, interferon-treated patients with both HBV and HCV infections were excluded. Furthermore, in HBV patients, those administered nucleos（t）ide analogues were excluded, and in HCV patients, those administered direct acting antivirals were also excluded. Studies citing hazard ratios of HCC regarding inflammation（serum elevated alanine aminotransferase levels） were selected. Finally, there were 14 studies of HBV-infected patients and 8 studies of HCV-infected patients. We calculated the hazard ratio in patients in an inflammatory state（serum ALT levels were above the normal range）.RESULTS In the 14 studies of HBV patients, the average hazard ratio（HR） of elevated ALT for developing HCC was 2.74 [1.98-3.77] and that in the 8 studies of HCV-infected patients was 5.51 [3.08-9.83]. The HR of inflammation for HCC development in HCV-associated liver diseases is about twice that in HBV-associated liver diseases. HR in HCV-infected patients was significantly（P = 0.0391） higher than that in HBV-infected patients. In hepatitis B patients, the abnormal range adopted was 28-45 IU/L, and in hepatitis C patients, it was 20-50 IU/L. It was demonstrated that the abnormal ALT levels adopted in hepatitis B and C patients were very similar in this series.CONCLUSION The difference in the incidence of HCC development between HBV and HCV patients may depend on the difference in the hazard risk of ALT between HBV and HCV infections.