A Case-Control Study of the Epidemiology of Benign Breast Diseases with Reference to Oral Contraceptive Use

Abstract

Various characteristics of the epidemiology of benign breast diseases were examined in a study of 384 women with these conditions and 384 individually matched controls seen at two hospitals in New Haven, Connecticut. Cases with benign breast diseases were significantly more likely to be nulliparous than their matched controls and had given birth to significantly fewer children than these controls. Long-term oral contraceptive use was negatively associated with risk for benign breast diseases. There were no significant differences between cases and controls in any of the other variables considered, including age at first live birth, age at menarche, familial history of breast cancer, and lactation history.