N° 188
26 May 2008 

Genetic variants affect cancer risk in alcohol drinkers

Variants in certain genes lower the risk of various types of cancers in individuals who consume alcohol, reports a study published online this week in Nature Genetics. The genes, which encode enzymes that metabolize alcohol, reduce cancers of the mouth, larynx, pharynx and oesophagus.

Alcohol consumption is a risk factor for cancers of the upper aerodigestive tract, and some published evidence supports the notion that variation in the enzymes that metabolize alcohol - alcohol dehydrogenases (ADH) - might influence cancer susceptibility.

Paul Brennan and colleagues genotyped 6 ADH variants in more than 3,800 individuals with aerodigestive cancer and over 5,200 controls. One variant each in ADH1B and ADH7 were significantly protective against aerodigestive cancer specifically in individuals who were alcohol drinkers, and most strongly in those who had higher alcohol intake. Individuals with the protective variant in ADH1B are known to metabolize alcohol up to 100 times faster than those without it, suggesting that lower exposure to alcohol is protective against the disease.

'It has been known for some considerable time that alcohol drinking is a risk factor for cancer although its importance has been underestimated” said Dr Peter Boyle, Director of the International Agency for Research on Cancer. “These findings contribute considerably to the understanding of the mechanism of action of alcohol as a carcinogen.'

'The results also highlighted the role of alcohol in causing these cancers as the genes had no effect among people who did not drink alcohol, and became more important with higher levels of alcohol consumption', said Dr Brennan.

Dr Paul Brennan (International Agency for Research on Cancer, Lyon, France)
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Genetic Epidemiology Group
International Agency for Research on Cancer
150 cours Albert Thomas
Lyon 69008

The International Agency for Research on Cancer (

The International Agency for Research on Cancer (IARC) is part of the World Health Organization. Its mission is to coordinate and conduct research on the causes of human cancer, the mechanisms of carcinogenesis, and to develop scientific strategies for cancer control. The mandate of the world cancer research agency is to coordinate international research to take advantage of synergies and disseminate scientific information through publications, meetings, courses, and fellowships.

The Genetic Epidemiology Group within IARC conducts large scale case-control studies of specific cancers, and participates in international consortia, in order to ensure that studies have adequate sample size.

World Health Organization
International Agency for Research on Cancer
Organisation mondiale de la Santé
Centre international de Recherche sur le Cancer

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