by Jay Goldberg, MD, MSCP; Sara Mirghani, MD; and Sarah Woodman, MD
None of the authors has a conflict of interest to report with respect to the content of this article.
Many ob/gyns are confused or know little about multiple recently enacted state laws and proposed federal legislation related to screening mammograms that report increased breast density. These laws mandate or at least imply that a physician needs to take action when confronted with such a test result, but in general, they are not supported by known clinical facts.
The issue of mammographic breast density is well known in the radiology community whereas very little has been published about it in the ob/gyn and primary care literature. Failure to comply with your state’s breast density on mammography notification law, however, may place you at medico-legal risk if your patient later is diagnosed with breast cancer.
The Breast Imaging Reporting and Data System (BI-RADS) has 4 categories of parenchymal breast density on mammography: almost entirely fat, scattered fibroglandular densities, heterogeneously dense, and extremely dense (Figures 1 and 2). The last 2 categories, considered increased breast density, are noted in approximately half of mammography studies.
Dense breast tissue absorbs more radiation during mammography than does fatty breast tissue. This theoretically reduces the accuracy of mammography to detect breast cancer, but additional imaging of dense breasts does not statistically improve the diagnostic accuracy of mammography. In addition, compared to average breast density, the relative risks of breast cancer in women with heterogeneously dense and extremely dense breasts are reported to be increased by factors of 1.2 and 2.1, respectively.1
Connecticut enacted the first reporting law regarding mammographic breast density in 2009. Currently 24 states have similar laws requiring patient notification of increased breast density found on mammography. Many of these state laws also require or imply the need to offer patients the option of additional breast imaging. Only 4 states (Illinois, Indiana, Massachusetts, and New Jersey), however, mandate insurer financial coverage of additional breast imaging due to increased mammographic breast density (Figure 3).
The following 2 cases illustrate scenarios that many ob/gyns who order screening mammograms may face.