Alcohol and human cancer (review).

Epidemiological studies provide good evidence that alcoholic beverages are carcinogenic to the human liver, oesophagus, nasopharynx and larynx. There is some evidence that alcohol, when ingested in the form of beer, may be carcinogenic for the colon and rectum. Tenuous evidence exists for a link between cancer of the lung, urinary bladder, stomach and pancreas and alcohol consumption. The mechanism of action of alcohol as a carcinogen is not understood and it is likely that different mechanisms operate at different sites. Experimental models of alcohol carcinogenicity are largely unsatisfactory. However, it has been shown that alcohol can profoundly alter the metabolism of nitrosamines, which are known potent carcinogens, and may also act as a tumour promoter following initiation by nitrosamine.