Do aflatoxin-DNA adduct measurements in humans provide accurate data for cancer risk assessment?

Primary hepatocellular carcinoma is one of the most lethal and most common cancers in Africa and Asia and is associated with exposure to aflatoxin (AF) B1. To date, many human studies have relied upon presumptive intake data, rather than on quantitative analyses of AF-DNA adduct and metabolite content obtained by monitoring biological fluids from exposed people. Information obtained by monitoring exposed individuals for specific DNA adducts and metabolites will define the pharmacokinetics of AFB1, thereby facilitating risk assessment. In addition, using an animal model based on the differential effects of ethoxyquin on the kinetics of AF-DNA adduct and gamma-glutamyl transpeptidase-positive foci formation, we have data to support the concept that measurement of the major, rapidly excised AFB-7-guanine (Gua) adduct in tissues and fluids is an appropriate dosimeter for estimating exposure status and risk in individuals consuming this mycotoxin.