Alcohol consumption across the life course and mammographic density in premenopausal women.

PURPOSE: Consumption of alcoholic beverages during adolescence and early adulthood has been consistently associated with higher breast cancer risk. The influence of alcohol consumption early in life on mammographic breast density, a marker of breast cancer risk, is inconclusive. This study examined associations of alcohol consumption across the life course with premenopausal mammographic density.

METHODS: The study population included 1211 premenopausal women in the Nurses' Health Study II without cancer, who recalled their alcohol consumption at age 15 through enrollment in 1989 (baseline), and had mammograms available. Recent alcohol consumption was updated over follow-up. Percent and absolute measures of mammographic density were quantified on digitized film mammograms. Generalized linear regression was used to assess associations.

RESULTS: There were no notable differences in any of the three density measures for alcohol consumption at any age (15-17, 18-22, 23-30, and 31-mammogram). Neither alcohol consumption before first pregnancy nor after first pregnancy was significantly associated with any of the three density measures.

CONCLUSIONS: Moderate alcohol consumption during different age intervals during adolescence and early adulthood was not associated with mammographic density in premenopausal women.