Abstract
Adolescent exposures may be important in the development of breast cancer later in life. We examined the association of adolescent alcohol consumption and adult mammographic density, a strong risk factor for breast cancer. Women within the Minnesota Breast Cancer Family Cohort with detailed mammogram and risk factor information (n = 1,893) formed our sample. Breast cancer cases were excluded. Adolescent alcohol consumption (before age 18) was solicited through a mailed questionnaire. Percent density (PD) was estimated using the computerβassisted thresholding program, Cumulus. Statistical analyses were performed using linear mixed effect models. Women who reported ever drinking alcohol before age 18 (n = 390; 21%) had a higher unadjusted PD than women who never drank during adolescence (
$\hat{\mu}$~unadj~ = 26.5% vs. 22.2%), but this difference disappeared with adjustment for risk factors for mammographic density ($\hat{\mu}$~adj~ = 21.0% vs. 21.2%, p = 0.94). Adult PD was not associated with age at initiation, amount of alcohol consumed at one sitting or frequency of alcohol use before age 18. The lack of differences was seen across strata of menopausal status. There was suggestion of higher PD among heavy and more frequent drinkers (24.0%, 95% CI 21.1β26.8%) compared to lighter (21.3%, 95% CI 20.3β22.3%) and never drinkers (21.4%, 95% CI 20.9β21.9%) and also among regular adolescent drinkers who were daily or weekly adult drinkers (25.0%, 95% CI 23.0β27.0%) compared to less regular drinkers in these 2 time periods (23.0β23.4%). However, these associations were not statistically significant (p = 0.27 and p = 0.22, respectively). In summary, there was no evidence that adolescent alcohol use was associated with large and persistent effects on adult PD. Β© 2005 WileyβLiss, Inc.