Alcohol and Breast Cancer Risk (IMAGE) Washington University School of Medicine Caption If a female averages a drink per day between her first period and her first full-term pregnancy, she increases her risk of breast cancer by 13 percent, according to a new study from Washington University School of Medicine in St. Louis. Credit Washington University School of Medicine in St. Louis Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.