Adolescent intakes of alcohol and folate and risk of proliferative benign breast disease.

Abstract

169 Background: Given the importance of exposure between menarche and first childbirth in breast cancer risk, adolescent alcohol consumption may influence the risk of proliferative benign breast disease (BBD). Folate may modify the adverse effect of alcohol on breast cancer. Methods: We used data from 29,329 women in the Nurses’ Health Study II who completed both adolescent alcohol consumption questions in 1989 and an adolescent diet questionnaire in 1998. A total of 666 women with proliferative BBD between 1991 and 2001 were confirmed by centralized pathology review. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for established risk factors of breast cancer. Results: Adolescent alcohol consumption was dose-dependently associated with an increased risk of proliferative BBD (HR = 1.12 per 10g/day consumption; 95% CI, 1.03-1.22). There was no significant association with adolescent folate intake. While the interaction between adolescent alcohol and folate intake was not statistically significant, among women with low folate intake (<279 mg/day) the BBD risk was significantly increased with moderate alcohol intake (HR = 1.62; 95% CI, 1.14-2.28) and with high alcohol intake (HR = 1.90; 95% CI, 0.98-3.70; Ptrend <0.01). Adolescent alcohol consumption was not associated with increased risk among women with higher adolescent folate intake. Conclusions: Adolescent alcohol consumption is associated with higher risk of proliferative BBD, especially in women with low adolescent folate intake.