Discussions of Dense Breasts, Breast Cancer Risk, and Screening Choices in 2019

Breast density, a radiologic term that describes the proportion of parenchymal relative to fatty tissue in mammograms, is a strong and prevalent risk factor. With increasing breast density, the risk of having a breast cancer masked or hidden on mammography increases, as does future breast cancer risk.1 Almost 50% of US women aged 40 to 74 years have dense breasts (an estimated 27.6 million women). The widespread incorporation of breast density information into screening mammography reports in 36 US states and suggestion to consider supplemental imaging has resulted in women raising questions about breast density and supplemental imaging with their clinicians.2 Thus, clinicians need to be knowledgeable of the clinical significance of breast density and how it may be useful when combined with breast cancer risk to inform screening discussions.