A new review of research that looks at the relationship between alcohol consumption and breast cancer has found that low level or moderate drinkers who consume just one drink a day have a 5 per cent increased risk of breast cancer.
The analysis, published in the journal Alcohol and Alcoholism, discovered that heavy alcohol consumption, defined as three or more drinks a day, was found to have between a 40 per cent and 50 per cent increased risk of breast cancer.
Overall, alcohol drinking accounts for roughly 5 per cent of breast cancers in Northern Europe and North America and up to 10 per cent in countries such as Italy and France, where drinking alcohol is common among women.
When analysing the effects of light alcohol drinking, the authors — Helmut K Seitz and Carlo La Vecchia et al — reviewed research published before November 2011 via a literature search from MEDLINE, ISI Web of Science and EMBASE.
In total, 3,431 research papers were retrieved from the literature search. Of these, 113 papers reporting breast cancer risk estimates for light drinkers were included in the meta-analysis, which comprised 44,552 cases in the reference category of non-drinkers and 77,539 cases in the light-drinking category. Just over half (51 per cent) of the studies were from North America, 38 per cent from Europe, 6 per cent from Asia and 10 per cent from other regions.
Cancer of the female breast is slightly different to other body organ cancers, as even small doses of alcohol can stimulate breast cancer development.
As alcohol consumption might affect the risk of cancer through hormone-related mechanisms, the review particularly looked at the association between alcohol consumption and the risk of breast cancer through hormone-related mechanisms such as oestrogen receptor (ER) and progesterone receptor (PR) status. Seitz et al found that there was significant research to suggest that alcohol consumption increased the risk of all ER+ tumours by 27 per cent and placed a 14 per cent risk for all ER-breast cancers for the highest vs lowest level of alcohol drinking.
Subsequent investigations by the team found further support for a stronger association between heavy alcohol consumption and ER+ breast cancers.
Alcohol and Alcoholism published by Oxford University Press, doi: 10.1093/alcalc/ags011.