Alcohol abuse has multiple adverse effects on health, but few people are aware that an increased risk of cancer is one of the consequences of heavy alcohol use. In 1988, however, the International Agency for Research on Cancer (IARC) considered the available evidence for the relationship between alcohol drinking and cancer risk. It concluded that alcoholic beverage consumption is causally related to an increased risk of cancer of the liver and of the upper aerodigestive tract (UADT), which includes the oral cavity, pharynx, larynx and oesophagus. Although the finding that alcoholic beverages are carcinogenic to humans was significant, this did not necessarily mean that alcohol was itself the carcinogenic factor. Left open was the possibility that other chemicals in alcoholic beverages might be responsible for the carcinogenicity. Recently, this picture has changed, with significant implications for public health and the way that physicians should evaluate their patients' alcohol consumption, with a newly identified role for common genetic variants that alter the metabolism of alcohol and thereby alter risk.
