Awareness of Implications of Breast Density Remains Low
‘Improved education necessary to augment new legislation’
Extremely high breast density, which occurs in approximately 8% of women ages 40 to 75, is associated with a four- to six-fold increased risk of breast cancer compared with women with very low density. Unfortunately, though, most women remain unaware of this relationship and few know that tumor identification is more difficult in women with dense breasts, a new study shows.
Only about half of the states in the U.S. require that women with dense breasts on mammography be notified of the finding, and even when identified, insurance companies may not be required to pay for secondary screening.
The study, published in the Journal of the American College of Radiology, was based on a phone survey of 1,024 women ages 35 to 70 in Virginia. The results showed that few women were aware that breast density is a risk factor for breast cancer, and fewer still knew that the sensitivity of mammography is reduced in women with dense breasts. Three-fourths of the women surveyed had a mammogram in the past 5 years, but only half of the those who had a mammogram in the past year were aware of their breast density, and only one in five were aware that dense breasts reduces the sensitivity of mammography. Further, only one in eight women surveyed were aware that density increases breast cancer risk.
The authors, led by Thomas M. Guterbock, PhD, director of the University of Virginia Center for Survey Research in Charlottesville, found that only 39% of the women said they had been informed about the density of their breasts by healthcare providers. One third of the women who had mammograms said they were not familiar with the concept of breast density at all.
“And among women who had been informed about the density of their breasts, 53% said they had never heard anything about the relationship of breast density to the risk of breast cancer.” Overall, only 25% indicated that they had any knowledge about the relationship between breast density and breast cancer risk.
The results point to the need for better education and outreach, Guterbock and colleagues said, especially for women of low education and African American women, who were less knowledgeable about breast density and may particularly benefit from public education efforts. “In addition, knowledge about breast density among women of Jewish ancestry was lower than would be expected based on their levels of education. Improved education about breast density — both for the public and for providers — is necessary to augment new legislation to help women evaluate and manage their breast cancer risk.”
Another co-author, Jennifer A. Harvey, MD, of the University of Virginia’s Department of Radiology and Medical Imaging, told MedPage Today that clinicians should consider additional screening methods to complement mammography in women with dense breasts: “Specifically, screening with ultrasound can detect 30% more cancers than mammography alone in women with dense tissue. Tomosynthesis — 3D mammography — can also find more cancers, especially for women with heterogeneously dense tissue. It is less helpful for women with extremely dense breasts, though.”
The findings should be augmented with further research into the kind of information and messaging that will best inform women about the implications of breast density, the investigators wrote.
A group focused on breast density, called INFORMD (INformation FORum on Mammographic Density), made up of breast cancer researchers in Australia, explained that although breast density can be measured at the time of mammography, it is still not yet clear how to best use the information to help in early detection and prevention. “There is considerable research ongoing in this area, however, and in the meantime, we think it is important to start a conversation about breast density to help inform women about this very important risk factor that in the future could improve mammographic screening and provide better breast cancer outcomes.”
The group lists several key actions required to help women with dense breasts make informed decisions about screening: (1) Develop evidence-based guidelines for general practitioners and other health professionals to assist women to make informed decisions; and (2) Implement better methods to quantify breast density and improve methods to predict which women are most likely to develop breast cancer. “In this way, breast density can be reported to all women attending screening programs, along with evidence-based recommendations for their management.”
INFORMD also points to supplementary screening methods, including ultrasound and magnetic resonance imaging, but cautions: “It is important that women consider the costs, both emotional and financial, and the risk of false-positive results associated with these other technologies.”