Impact and Assessment of Breast Density

Abstract

Breast density, or the amount of fibroglandular tissue in the breast, is a recognized and independent marker for breast cancer risk. In addition, breast density reduces the sensitivity of mammography due to a masking effect. Public awareness of the importance of breast density has resulted in legislation for reporting breast density for risk stratification purposes. To date, breast density assessment is performed with mammography and to some extent with magnetic resonance imaging. Data indicate that computerized, quantitative techniques in comparison with subjective, visual estimations are characterized by higher reproducibility and robustness. Standardized breast density assessment using automated volumetric quantitative methods has the potential to be useful for risk prediction, stratification, and determining the best screening plan for each woman. This chapter provides a comprehensive overview of the currently available imaging modalities for qualitative and quantitative breast density assessment and the current evidence on breast density and breast cancer risk assessment.