Study summary: The current study was designed to determine whether early, lifetime or recent alcohol consumption was associated with breast cancer risk, and whether the risk varied by type of drink. The study included 1,728 newly-diagnosed breast cancer patients and 435 controls 20 to 49 years of age. Intake of alcoholic during the 5-year period before breast cancer diagnosis was found to be associated with increased risk of breast cancer. Consuming at least two alcoholic drinks per day during this 5-year period was associated with an 82% increase in breast cancer risk compared to those who had never been drinkers (OR = 1.82, 95% CI = 1.01–3.28). No increase in risk was found for alcohol intake at ages 15 to 20 years or for lifetime alcohol intake. Risk also did not vary by type of alcoholic drink consumed. The authors conclude that recent alcohol consumption may be associated with increased breast cancer risk in young women.