Dense breast notification controversies and guidelines

Dr. Laura T. MercerLaura T. Mercer, MD, District VIII Junior Fellow chair

We’ve heard much about dense breasts in the last several years, from Connecticut to California. In District VIII, legislation about dense breasts has surfaced in many states. At both the Congressional Leadership Conference in March and the Interim District Advisory Council Meeting in April, District VIII officers discussed this issue.

Radiologists classify breasts into one of four categories of breast density:

  • Almost entirely fatty
  • Scattered areas of fibroglandular density
  • Heterogeneously dense
  • Extremely dense 

The reasoning behind legislation mandating dense breast notification is that the sensitivity of mammography decreases as the density of one’s breasts increases. At the same time, there is a modest increase in risk of breast cancer in women with dense breasts. Most legislation mandates lay notification of breast density when a woman’s breasts are in either of the last two categories mentioned above. Fifty percent of women’s breasts fall into those categories.

Arizona recently became the 15th state to pass dense breast notification legislation. The law requires the following notice be sent to women with heterogeneously dense or extremely dense breasts from the institution or facility that performed their mammogram:

“Your mammogram indicates that you have dense breast tissue. Dense breast tissue is common and is found in 50% of women. However, dense breast tissue can make it more difficult to detect cancers in the breast by mammography and may also be associated with an increased risk of breast cancer. This information is being provided to raise your awareness and to encourage you to discuss with your health care providers your dense breast tissue and other breast cancer risk factors. Together, you and your physician can decide if additional screening options are right for you. A report of your results was sent to your physician.”

Physicians are left with how to counsel patients who receive this information and how to answer their questions. Unfortunately, the data on breast density and breast cancer is scarce, and we have little to guide us on what the next best steps should be for women in these categories. ACOG published a Committee Opinion in the April Green Journal that addresses breast density. It states that “ACOG does not recommend routine use of alternative or adjunctive tests to screening mammography in women with dense breasts who are asymptomatic and have no additional risk factors.”

Wondering what those additional risk factors might include? Check out guidelines from the National Comprehensive Cancer Network or the National Cancer Institute to determine who should go on to have genetic counseling or other screening tests.

More studies are examining just how effective (and possibly harmful) breast cancer screening can be for women. Additionally, studies examining how to determine who, when, and at what intervals we should be screening are increasing. The discussion on breast cancer screening, mammography, and breast density is far from over.