Most women don't know that having dense breasts increases their risk for breast cancer and reduces a mammogram's ability to detect cancer, according to a University of Virginia School of Medicine study.

A random phone survey of 1,024 Virginia ages 35 to 70, conducted by the UVA Center for Survey Research, found that just 1 in 8 women were aware that is a risk factor for breast cancer, while just 1 in 5 women knew that reduced the sensitivity of mammograms to find tumors.

"It is important for women to know whether or not their own breast density is classified into one of the two high-density categories since this will increase their ," said study co-author Wendy Cohn, PhD, an associate professor in UVA's Department of Public Health Sciences. "Women need to know whether their breast density will make it harder to detect breast cancer so that, along with their healthcare team, they can consider other options for screening and detection."

How Physicians Can Help Educate Women

Virginia is among at least 27 states that require radiologists to tell women about their breast density, according to the study, and providing that information improves women's understanding of how breast density may impact their health.

The survey found that the strongest factor in knowing about breast density and its relationship with breast cancer was whether a healthcare provider had informed a woman about the density of her breasts. UVA researchers stressed the importance of a conversation between patients and healthcare providers about the impact of breast density.

"The most important thing that doctors and patients can take away from this study is that the required written notice about breast density isn't enough in itself: patients need to talk with their providers about what breast density means for each woman's individual risk," said Thomas Guterbock, a professor of sociology and director of the UVA Center for Survey Research.

More information: Thomas M. Guterbock et al, What Do Women Know About Breast Density? Results From a Population Survey of Virginia Women, Journal of the American College of Radiology (2016). DOI: 10.1016/j.jacr.2016.07.003

Journal information: Journal of the American College of Radiology