Alcohol consumption and the risk of breast cancer among BRCA1 and BRCA2 mutation carriers.

Alcohol consumption increases the risk of breast cancer among women in the general population, but its effect on women who carry a BRCA gene mutation is unclear. We conducted a case-control study of 1925 matched pairs of predominantly premenopausal women who carry a BRCA1 or a BRCA2 mutation. Information on current alcohol consumption was obtained from a questionnaire administered during the course of genetic counselling or at the time of enrollment. A modest inverse association between breast cancer and reported current alcohol consumption was observed among women with a BRCA1 mutation (OR = 0.82, 95% CI 0.70-0.96), but not among women with a BRCA2 mutation (OR = 1.00; 95% CI 0.71-1.41). Compared to non-drinkers, exclusive consumption of wine was associated with a significant reduction in the risk of breast cancer among BRCA1 carriers (p-trend = 0.01). Alcohol consumption does not appear to increase breast cancer risk in women carrying a BRCA gene mutation.