Chronic infection with HBV has been established as a cause of hepatocellular carcinoma (HCC), a type of liver cancer. More than 350 million people worldwide have a chronic infection with one of the seven known genotypes, or subtypes, of HBV. Although there are some known risk factors for HCC development, it is unclear what role HBV subtype or viral load--the amount of the virus in the blood--might have on cancer development.

To determine whether HBV genotype and viral load are associated with HCC risk, Ming-Whei Yu, Ph.D., of National Taiwan University in Taipei, and colleagues conducted a nested casecontrol study among male Taiwanese HBV carriers who had not been diagnosed with HCC. HBV DNA levels--a measure of viral load--and genotypes were determined for 154 case patients (men who were diagnosed with HCC during 14 years of follow-up) and 316 control subjects.

Greater viral load was associated with an increased risk of HCC; men in the quintile with the highest viral load had more than seven times the risk of HCC compared with men in the lowest quintile. Genotype C was associated with a five-fold increased risk of HCC compared with all other genotypes. Genotype C was also associated with increased viral load. In addition, the effects of genotype C and increased viral load were additive; men carrying genotype C who had a high viral load had nearly 26.5 times the risk of developing HCC as men with other genotypes who were in the lowest two quintiles of viral load.

"[W]e found that higher plasma HBV DNA levels and infection with genotype C HBV were independently (and additively) associated with an increased risk of HCC among Taiwanese men," the authors w
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Contact: Sarah L. Zielinski
jncimedia@oupjournals.org
301-841-1287
Journal of the National Cancer Institute
15-Feb-2005