Research from Dartmouth Cancer Center suggests that testing women's knowledge of breast density offers opportunities for learning and improvement
Lebanon – Breast density is a factor in assessing a person's risk of developing breast cancer. Existing state breast density notification laws have increased breast density awareness among patients and providers, but clinical records have not been included in the study to confirm the accuracy of individual breast density knowledge. A research team from the Dartmouth Cancer Center worked with both women surveyed by the Breast Cancer Surveillance Consortium and included their clinical records from 15 mammography facilities across three states to find out how much women know about breast density.
The study, recently published online in the Journal of the American College of Radiology, “Breast Density Knowledge in a Screening Mammography Population in Exposed to Density Notification” found that although knowledge of breast density may increase due to existing state laws, there is still room. To improve, and physicians need tools to engage with women to understand their personal breast cancer risk and screening options.
“Those who are less literate should be given special consideration in the design of these tools,” said lead author Rebecca Smith, MS, Dartmouth, a PhD student at the Dartmouth Institute for Health Policy and Clinical Practice doctoral program in Dartmouth. “Standard breast density communication may also benefit all women – women with thick and non-thick breasts – as opposed to women with only thick breasts.”
The team set out to measure the accuracy and prognosis of women's breast density in a nationally representative sample of women eligible for breast cancer screening who had never had breast cancer before. They also examined women's understanding of the effects of breast screening and future screening intent on breast density.

“Decision support tools will be needed to keep abreast of who is benefiting from complementary screening of healthcare providers and the evidence that has been developed to involve women in shared decision-making,” Smith said. “Density notifications should be useful and accessible across a wide range of literacy levels. For women with both thick and non-thick breasts, standard breast density communication can be an advantage. “
The majority of women with dense breasts (76%) knew their breast density accurately, while most women with non-dense breasts did not know it (14%). About one-third of women who do not have breasts have thicker breasts, and women who believe they have thicker breasts are more likely to have supplemental screening than women who do not have breasts. Reporting the density of all women compared to only women with dense breasts, was associated with an increased potential for accurate breast density knowledge for women without dense breasts. Lower education was associated with less opportunity to know one's own concentration properly.

Anna Tostesson, ScD, associate director of demographic science at the Dartmouth Cancer Center and senior author of the study, notes, “The results of our study are important for policy makers to consider when designing pending national breast density notification regulations.”