Alcohol intake and breast cancer risk among young women

Introduction Alcohol intake has been consistently associated with breast cancer risk, but the importance of timing of intake and the impact of beverage type are unclear. Methods We evaluated whether early, lifetime or recent alcohol intake was associated with breast cancer risk, and whether risk varied by type of alcoholic drinks in 1,728 newly diagnosed population-based breast cancer patients and 435 control subjects aged 20-49 years. We used multivariable logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI) as measures of the relative risk of breast cancer associated with intake of alcoholic drinks. Results Intake of alcoholic drinks during the recent five year period before the breast cancer diagnosis was associated with increased breast cancer risk (P-trend = 0.04). Intake of two or more alcoholic drinks per day during this five year period was associated with an 82% increase in breast cancer risk relative to never drinkers (OR = 1.82, 95% CI = 1.01-3.28). No risk increase was observed for alcohol intake at ages 15-20 years or for lifetime alcohol intake. Risk did not vary by type of alcohol consumed. Conclusions Our results suggest that recent alcohol consumption may be associated with increased breast cancer risk in young women.