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BACKGROUND: Hepatocellular carcinoma (HCC), or liver cancer, is the third leading cause of cancer deaths worldwide, with prevalence 16-32 times higher in developing countries than in developed countries. Aflatoxin, a contaminant produced by the fungi Aspergillus flavus and Aspergillus paranticus in maize and nuts, is a known human liver carcinogen.
OBJECTIVES: We sought to determine the global burden of HCC attributable to afiatoxin exposure.
METHODS: We conducted a quantitative cancer risk assessment, for which we collected global data on food-borne aflatoxin levels, consumption of aflatoxin-contaminated foods, and hepatitis B virus (HBV) prevalence. We calculated the cancer potency of aflatoxin for HBV-postive and HBV-negative individuals, as well as the uncertainty in all variables, to estimate the global burden of aflatoxin-related HCC.
RESULTS: Of the 550,000-600,000 new HCC cases worldwide each year, about 25,200-155,000 may be attributable to aflatoxin exposure. Most cases occur in sub-Saharan Africa, Southeast Asia, and China where populations suffer from both high HBV prevalence and largely uncontrolled aflatoxin exposure in food.
CONCLUSIONS: Aflatoxin may play a causative role in 4.6-28.2% of all global HCC cases.
KEY WORDS: aflatoxin, global disease burden, hepatitis, hepatocellular carcinoma, risk assessment. Environ Health Perfect 118:818-824 (2010). doi:10.1289/ehp.0901388 [Online 19 February 2010]
Hepatocellular carcinoma (HCC), or liver cancer, is the third leading cause of cancer deaths worldwide [World Healdi Organization (WHO) 2008], with roughly 550, GOO600, 000 new HCC cases globally each year (Ferlay et al. 2004). Aflatoxin exposure in food is a significant risk factor for HCC (Wild and Gong 201 0). Aflatoxins are primarily produced by die food-borne fungi Aspe rgillus flavus and Aspergillus parasiticus* which colonize a variety of food commodities, including maize, oilseeds, spices, groundnuts, and tree nuts in tropical and subtropical regions of the world. Additionally, when animals that are intended for dairy production consume aflatoxin-comaminated feed, a metabolite, aflatoxin M1, is excreted in the milk (Strosnider et al. 2006).
Aflatoxins are a group of approximately 20 related fungal metabolites. The four major aflatoxins are known as B], B2, G], and G2. Afla toxins B3 and G2 are the dihydroderivatives of the parent compounds B1 and G1 (Pirt and Tomaska 2001). Aflatoxin B1 (AFBl) is the most potent (in some species) naturally occurring chemical liver carcinogen known. Naturally occurring mixes of aflatoxins...