The Divide Between Breast Density Notification Laws and Evidence-Based Guidelines for Breast Cancer Screening: Legislating Practice

In 2003, Dr Nancy Cappello was stunned by her diagnosis of breast cancer just 6 weeks after normal findings on mammography.¹ She subsequently discovered medical literature documenting the lower sensitivity of mammography in women with dense breast tissue, as well as the association between greater breast density and increased cancer risk. Frustrated by the reluctance of her physicians to discuss the potential role of breast density in her diagnosis, Cappello pursued legislation in Connecticut, where she lived. The legislation was enacted, requiring insurers to cover breast ultrasonography as an adjunctive screening test to mammography for women with dense breast tissue and to notify women of their breast density results and the potential effect on the sensitivity of screening. As of April 2015, breast density notification laws had been enacted in 22 states and are advancing in an additional 13 states, and federal legislation has been introduced.² Modeling suggests that at least 28 million women in the United States between the ages of 40 and 74 years (43% of women in this age group) could be affected by such legislation.³