A Comprehensive Examination of CYP19 Variation and Breast Density

Abstract

Study subjects were women without a history of cancer visiting Mayo Department of Internal Medicine for a medical exam. These women were controls for a breast cancer case-control study (described in ref. 7) who provided informed consent, a written questionnaire, and a blood sample. Postmenopausal status was defined as having no menstrual period for 12 months or having a hysterectomy or oophorectomy. Hormone therapy was categorized as “currently taking,” “taken in the past,” or “never used.”