Cancer risks derived from alcohol.

Most cancers of the upper aero-digestive tract are related to alcohol consumption. For the mouth, oesophagus and larynx a positive dose-response relationship has been observed, as well as a combination effect with tobacco smoking--according to a multiplicative model in the case of the oesophagus. Nutritional factors also play a role. For other cancer sites, the role of alcohol is controversial, except for primary liver cancer which often develops on a cirrhotic liver. The mechanisms by which alcohol increases cancer risk are still obscure. It is not considered to be a carcinogen by itself but rather as a co-carcinogen, facilitating or enhancing the role of other carcinogens. Another mechanism might be the induction of microsomal enzymes activating pro-carcinogens. As in the case for smoking, prevention can be achieved by abstention or reduction of consumption. This has to be considered seriously in countries where alcohol consumption is increasing.