Too many women still unaware of breast density as a cancer risk

When it comes to the awareness and knowledge of breast density, apparently not all women are alike, according to a Mayo Clinic study published in the Journal of Clinical Oncology.

For the study, researchers led by Deborah J. Rhodes, M.D., associate professor of medicine at Mayo Clinic in Rochester, Minn., conducted a national cross-sectional survey (in both English and Spanish) of 2,311 women ages 40 to 74. Of the women who responded to the survey (it had a 65% response rate), 58% had heard of breast density, 49% percent were aware it affected breast cancer detection and 53% knew it was associated with breast cancer risk.

Less than half of the women who were aware of breast density had discussed their own breast density with a healthcare provider, and in most cases those discussions were initiated by the provider. “It is plausible that the spread of BD legislation will empower women to initiate these discussions and participate more actively in screening decisions,” the authors suggested.

When the authors broke down the study according to race and ethnicity, they found differences in the levels of knowledge and awareness. For example white, non-Hispanic women were more likely to have an increased level of breast density awareness than minority women.

In addition, women with higher incomes or those who had received postmenopausal hormone therapy or a diagnostic evaluation after a mammogram were also more likely to have an increased level of breast density awareness.

Given that women with MDBs [mammographically dense breasts) are at risk for recall after screening mammography, it is possible that breast diagnostic evaluation provides the setting for [breast density] discussions with providers,” the authors observed.

The authors also found that women from Connecticut—the first state to put breast density legislation on the books in 2009—were more likely than women from other states to understand the effect of breast density on cancer detection and to have engaged in a breast density discussion with a healthcare provider.

Rhodes and her colleagues said there are additional concerns about raising breast density awareness. For example, the authors noted there is no consensus on supplemental screening for women with  MDBs at low risk, and that there is also a lack of a standard classification for dense breasts.

But, breast density awareness—even without supplemental screening consensus or precise classifications—is “important,” the authors noted. “No other routine screening test performance varies so widely based on a known patient characteristic. To make fully informed screening decisions, women should be aware of the differential performance characteristics of mammography based on breast density.”

In addition, woman with MDBs need to understand there are higher false-negative rates associated with mammography and that they need to be “vigilant’ about reporting any breast changes even after having had a mammogram that was interpreted as negative or benign. 

Finally, “given the impact of hormone therapy on breast density and mammography sensitivity, along with the increased risk of breast cancer (and advanced-stage breast cancer) among women with extremely dense breasts who use hormone therapy,” the authors wrote, “[breast density] awareness is important in hormone therapy decision making.”