Mammographic Breast Density -- In the Eye of the Beholder on Any Given Day

Background: Mammographic breast density is judged as the proportion of fibroglandular tissue to fat on a given mammogram. Increase in breast density has been documented to be an independent risk factor for the development of breast cancer. Mammographic breast density has been adopted as part of the standardized reporting derived from the BI-RADS lexicon. Objective: To evaluate the reproducibility of mammographic breast density descriptions based on performance by community radiologists. Methods: Data were mined from the Vermont-based registry of the Breast Cancer Surveillance Consortium, a National Cancer Institute-supported nationwide clinical, radiologic, and pathologic registry. Over a 10-year period, mammographic breast density on women undergoing screening mammography was recorded. For the purposes of this study, only postmenopausal women were included in the analysis and only screen-film mammography was evaluated. Those women on hormone replacement therapy or those taking tamox more...