Estimating the global burden of aflatoxin -attributed hepatocellular carcinoma - A risk assessment

Objectives: Chronic hepatitis B virus infection (HBV+) and aflatoxin are known causes of hepatocellular carcinoma (HCC) or liver cancer, the 3rd-leading cause of cancer deaths worldwide. Aflatoxin is a fungal toxin found primarily in maize and peanuts. Both HBV infection and aflatoxin-contaminated foods are prevalent in developing countries, and the cancer potency of Aflatoxin is significantly enhanced in individuals with HBV infection. Our objective is to estimate the global burden of HCC attributable to aflatoxin exposure, by itself and in conjunction with chronic HBV infection.

Methods: We collected global data (by seven WHO regions) on foodborne aflatoxin levels, consumption of maize and peanuts, and HBV prevalence, to calculate global liver cancer risk from aflatoxin exposure. Aflatoxin's cancer potencies for HBV+ and HBV- individuals, and uncertainties in all variables were considered in calculations.

Results: Of the annual 550,000-600,000 new HCC cases worldwide, about 25,200-155,000 may be attributable to dietary aflatoxin. 90% of these cases occur in sub-Saharan Africa, Southeast Asia, and Western-Pacific region. If HBV vaccination were made universally available such that HBV prevalence were reduced to ≤2% worldwide, the number of aflatoxin-related HCC cases would drop to 13,400-65,400 annually.

Conclusions: Aflatoxin may play a causative role in 4.6-28.2% of all global liver cancer cases. The most affected areas are sub-Saharan Africa, Southeast Asia, and Western-Pacific region.

Public health implications: Efforts on interventions should be made in less-developed countries where aflatoxin is still a significant public health risk. Specifically, HBV vaccination can significantly reduce aflatoxin-related HCC cases in future generations.