Global geographical overlap of aflatoxin and hepatitis C: controlling risk factors for liver cancer worldwide.

About 85% of hepatocellular carcinoma (HCC, liver cancer) cases occur in low-income countries, where the risk factors of dietary aflatoxin exposure and chronic hepatitis B and C (HBV and HCV) viral infection are common. While studies have shown synergism between aflatoxin and HBV in causing HCC, much less is known about whether aflatoxin and HCV synergise similarly. From an exposure perspective, it was examined whether there is a geographical overlap in populations worldwide exposed to high dietary aflatoxin levels and with high HCV prevalence. While HCV is one of the most important risk factors for HCC in high-income nations (where aflatoxin exposure is low), it is found that HCV prevalence is much higher in Africa and Asia, where aflatoxin exposure is also high. However, within a given world region, there are some inconsistencies regarding exposure and cancer risk. Therefore, there is a need to control risk factors such as aflatoxin and hepatitis viruses in a cost-effective manner to prevent global HCC, while continuing to evaluate biological mechanisms by which these risk factors interact to increase HCC risk.