Breast density is an important risk factor for breast cancer, but it’s not clear what woman understand or think about this topic in relationship to their own screenings. Currently, 37 states have notification laws about breast density, but these laws vary.
In a new qualitative study,1 scientists at Dartmouth and Dartmouth-Hitchcock’s Norris Cotton Cancer Center and the Breast Cancer Surveillance Consortium sought to explore women’s knowledge and perceptions of breast density and experiences of breast cancer screening across three states, including those with and without notification laws.

The researchers conducted 90-minute focus groups with 47 women who had had recent normal mammograms but who had been identified as having dense breasts, according to data from the Breast Cancer Surveillance Consortium.

The researchers found that women had varying knowledge about their own breast density and the significance of breast density in general, even when they lived in states with notification laws. A number of the women were aware that having denser breasts makes it more difficult to detect cancer, but only one knew that density itself increased breast cancer risk.

“We found that very few women received information about breast density during healthcare visits although some were encouraged to get supplemental imaging or to pay for new types of mammography such as breast tomosynthesis,” says Karen Schifferdecker, PhD, MPH, of the Geisel School of Medicine at Dartmouth, who led the study. “Women who were offered more imaging or different technology usually thought these were ‘better,’ even though they were given little information about the effectiveness or harms.”

The study also found that women from all states expressed a strong desire for more information about breast density, and the researchers concluded that the medical community needs to do more to help women make informed decisions about breast density, mammography, and supplemental imaging.

“Women want—and deserve—more usable information about breast cancer risk,” says Schifferdecker. “More research needs to be done to understand how the medical community can better assist women in making informed decisions related to breast density and screening.”


  1. Schifferdecker KE, Tosteson ANA, Kaplan C, et al. Knowledge and perception of breast density, screening mammography, and supplemental screening: in search of “Informed.” J Gen Intern Med. doi:10.1007/s11606-019-05560-z.

Featured image:

 A physician reviews a mammogram with a patient. Photo © Evgeniy Kalinovskiy courtesy (ID 128483198).