More on Breast Density and Breast Cancer Risk

Background: Prior studies have shown that women with mammographically dense breasts have a higher risk of developing breast cancer than women of similar age whose breasts are relatively fatty. Furthermore, breast density has been shown to vary between different ethnic groups. Objective: To estimate the effect of breast density on breast cancer risk after adjustment for other risk factors based on a specific ethnic population in Europe deemed to be of intermediate risk. Methods: Data from a population-based registry formed as part of a nationwide breast cancer screening program were used. In this nationwide screening program, women aged 50 to 69 years are invited to undergo mammographic screening on a biannual basis. Standard 2-view mammography is performed and all cases are double read. Breast density was recorded at the time of the mammogram and was classified by use of the 4 conventional categories based on the American College of Radiology grading system. Breast cancer cases were more...