Alcohol use is a risk factor for many cancer types including cancer of the oral cavity, pharynx, larynx, oesophagus, liver, colorectum and breast. Risk of cancer increases with the amount of alcohol consumed. The risk from heavy drinking for several cancer types (e.g. oral cavity, pharynx, larynx and oesophagus) substantially increases if the person is also a heavy smoker. Attributable fractions vary between men and women for certain types of alcohol-related cancer, mainly because of differences in average levels of consumption. For example, 22% of mouth and oropharynx cancers in men are attributable to alcohol whereas in women the attributable burden drops to 9%. A similar sex difference exists for oesophageal and liver cancers (Rehm et al., 2004). In total, approximately 3.6% of all cancers worldwide are attributable to alcohol (Boffetta et al. 2006)
According to the Canadian Cancer Society, drinking 3.5 drinks per day can double or triple the risk of develoing cancer of the mouth, pharynx and esophagus, and increases the risk of colon, rectal and breast cancer by 1.5.
For more information:
World Health Organization website, November 2012
Canadian Cancer Society, July 2015
Breakdown by cancer:
Squamous-cell carcinoma of oral cavity, pharynx, larynx and oesophagus
There is a causal relationship between alcohol and squamous cell carcinoma in these areas. There is a linear correlation with both duration and amount of consumption. There is also a synergistic (more than additive) effect between smoking and alcohol consumption on these cancers.
Adenocarcinoma of the oesophagus
Some studies report an increased risk of 1.5 to 4.0 times with alcohol consumption2, however, other studies have failed to find an association3. Therefore, findings in this area are inconclusive.
Stomach Cancer
There is no consistent evidence linking alcohol with increased risk of stomach cancer. There has been some limited evidence of increased stomach cancer risk with specific alcoholic drinks, including vodka in Russia, wine in Italy, and hard liquor and beer in Uruguay, however, there is no clear defined relationship.
Colorectal Cancer
A review of epidemiological studies showed risk estimates of 1.0 to 1.7 for both colon and rectal cancer, corresponding to a slightly increased risk with alcohol consumption3.
Liver Cancer
Drinking large amounts of alcohol is a risk factor for the development of hepatocellular carcinoma. Heavy drinkers have a 1.8 times increase in risk for developing liver cancer4.
Breast Cancer
Risk estimates for breast cancer were 1.1 for one drink a day, 1.2 for two drinks a day and 1.4 for three or more drinks per day5. This corresponds to about a 7% increase in risk for every additional 10g a day in alcohol intake6.
For more information, there is a comprehensive review published on the relationship between alcohol and cancer7, written by P. Boffetta and M. Hashibe, here.
References:
1. Wu, A.H., Wan, P., Bernstein, L.A. (2001). A multiethnic population-based study of smoking, alcohol and body size and risk of adenocarcinomas of the stomach and esophagus. Cancer Causes Control 12: 721-732.
2. Zazridze, D., Borisova, E., Maximovitch, D., Chkhikvadze, V. (2000). Alcohol consumption, smoking and risk of gastric cancer: case-control study from Moscow, Russia. Cancer Causes Control 11: 363-371.
3. Franceschi, S., La Vacchia, C. (1994). Alcohol and the risk of cancers of the stomach and colon rectum. Dig Dis 12: 276-289.
4. Corraro, G., Bagnardi, V., Zambon, A., La Vecchia, C. (2004) A meta-analysis of alcohol consumption and the risk of 15 diseases. Preventative Medicine 38: 613-619.
5. Longnecker, M.P. (1994) Alcoholic beverage consumption in relation to risk of breast cancer: meta-analysis and review. Cancer Causes Control 5: 73-82.
6. Smith-Warner, S.A., Spiegelman, D., Yaun, S.S., et al. (1998) Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA 279: 535-40.
7. Boffetta, P., and Hashibe, M. (2006) Alcohol and Cancer. Lancet Oncology 7: 149-156.