Alcohol consumption significantly increases cancer risk in women, UK study reveals

New data from the UK's 'Million Women Study' —a collaborative project between Cancer Research UK and the National Health Service—indicates that:

Low to moderate alcohol consumption among women is associated with a statistically significant increase in cancer risk and may account for nearly 13 % of cancers of the breast, liver, rectum, and upper aero-digestive tract combined.

A total of 1,280,296 middle-aged women (aged 50 and over) in the United Kingdom enrolled in the 'Million Women Study' were routinely followed for incident cancer. On average, the women consumed one drink per day, and the type of alcoholic beverage consumed did not alter the relationship between consumption and cancer risk. Within this large cohort, 68,775 women were diagnosed with cancer.

Increasing but moderate alcohol consumption in women was determined to be associated with an increased risk of cancers of the oral cavity and pharynx, esophagus, larynx, rectum, breast, and liver. For these cancers combined, there was an excess of about 15 cancers per 1000 women per drink per day. Women who also smoked had an increased risk of cancers of the oral cavity and pharynx, esophagus, and larynx. The study did show a decreased risk for thyroid cancer, non-Hodgkin's lymphoma, and renal cell carcinoma with moderate alcohol consumption.

In the case of breast cancer, one theory is that alcohol interferes with estrogen metabolism, which in turn increases the risk of hormone-sensitive breast cancer—although there are breast tumors that are not hormone-related, as well. Mechanisms for incidence of the other cancers (besides liver cancer) to increase have not been proffered.

These findings appear in the February 24, 2009 online issue of the Journal of the National Cancer Institute