Hepatitis C virus infection in black patients with hepatocellular carcinoma in southern Africa.

Chronic hepatitis C virus (HCV) infection is implicated in the etiology and pathogenesis of a relatively small proportion of hepatocellular carcinomas (HCC) in black residents of southern Africa. The major risk factor for the tumor in this population is chronic hepatitis B virus (HBV) infection acquired early in life. Only 13.2% of black patients with HCC are currently infected with HCV (as judged by the presence of HCV RNA in serum) alone, and another 4.3% are infected with both HCV and HBV. Antibody to HCV can be detected with second generation assays in 19.5% of HCC patients. Fifty percent of the HCC patients have only current HBV infection and a further 35.9% show markers of past HBV infection (including 9.1% who also are currently infected with HCV). The prevalence of current HBV infection is significantly lower in HCV RNA-positive than in HCV RNA-negative patients, and this difference is independent of the sex, age, or geographical location of the patients. Only 5.4% of HCC patients are not infected with either HBV or HCV. Patients with HCV-associated HCC are appreciably older than those with tumors not associated with HCV and those with tumors associated with HBV, and the differences are independent of geographical location of the patients. Patients with HCV-associated HCC are more likely to be urban dwellers and less likely to be rural dwellers than are those with HBV-related tumors. Differences in sex distribution and alpha-fetoprotein levels just fail to reach statistical significance between patients with HCV-related and HBV-related HCC. The pathogenesis of HCV-related HCC in black Africans, as in all populations, is uncertain. A direct carcinogenic effect appears unlikely, and the available evidence favors an indirect effect mediated via chronic necroinflammatory hepatic disease. Because very few of our patients undergo surgery or have a necropsy performed, the relationship between HCV-associated HCC and cirrhosis in black Africans has not been analyzed.