Because alcohol is related to medical illnesses such as aerodigestive cancer and variations in alcohol metabolism are related to the development of alcohol dependence, a study was designed to evaluate whether genetic variation in ADH may contribute to the development of cancer of the upper aerodigestive tract, including several types of head and neck cancer that develop in the context of heavy alcohol and tobacco exposure.28 Based on 3800 subjects with aerodigestive cancer and 5200 controls, variants in ADH1B and ADH7 were found to be protective against aerodigestive cancer.28 Even after stratifying for site of cancer, alcohol consumption and other covariates, the protective effects were still strong. These effects suggest that ADH variants not only decrease the risk for alcohol dependence but also decrease the susceptibility to cancer associated with alcohol dependence, perhaps by modifying the carcinogenic effects of alcohol.
