University of Vermont

Sprague Study Shows Supplemental Breast Cancer Screening for Women with Dense Breasts Not Beneficial

Findings Could Impact Pending Breast Density Notification Legislation

Brian Sprague, Ph.D.
Brian Sprague, Ph.D., University of Vermont Assistant Professor of Surgery (Photo: COM Design & Photography)

A new study released in the Annals of Internal Medicine and led by Brian Sprague, Ph.D., at the University of Vermont Cancer Center concludes that supplemental ultrasound screening for women with dense breasts would substantially increase costs with little improvement in overall outcomes. The research provides needed evidence on the benefits and harms of breast cancer screening options for women with dense breasts, and informs the discussion of national legislation that would mandate the disclosure of breast density information to women. 

This collaborative study, funded by the National Cancer Institute, was conducted by Sprague and colleagues within the national Breast Cancer Surveillance Consortium and the Cancer Intervention and Surveillance Modelling Network, which provided advanced public health modeling for the project. The study estimates that for every 10,000 women between the ages of 50-74 with dense breasts who receive ultrasound screening exams after a normal mammogram, about four breast cancer deaths would be prevented, but an extra 3,500 biopsies would be performed in women who did not have breast cancer.

Mammographically-dense breasts – those that show more glandular and connective tissue versus fat in a mammogram image – are recognized as a risk factor for developing breast cancer and can also hamper an accurate reading of a mammogram. Recent research by Sprague and colleagues, published in the Journal of the National Cancer Institute, found that there is a high prevalence of women in the U.S. with mammographically-dense breast tissue, with more than 40 percent of women between the ages of 40 and 74 affected.

According to Sprague, “the national legislation currently under consideration would require the disclosure of mammographic breast density information to women with dense breasts, and encourage them to discuss supplemental screening options, such as ultrasound, with their providers.” Similar laws already exist in at least 19 states, including California, New York and Massachusetts. 

Sprague and his collaborators provide important information for policy makers considering national breast density notification laws.  “The fact that minimal health gains are projected with a substantial increase in biopsies and costs when ultrasound is used in screening underscores the need for further research into effective imaging strategies for women with dense breasts,” says Sprague, who is a cancer epidemiologist and assistant professor of surgery at the University of Vermont and co-director of the Cancer Control and Population Health Sciences research program at the University of Vermont Cancer Center.  “This should include the evaluation of new imaging technologies such as digital breast tomosynthesis, which holds promise for increasing cancer detection while also reducing false-positive results.”

Sprague and colleagues recently published a separate computer simulation modeling study using preliminary data on digital breast tomosynthesis that suggests this may provide an effective screening strategy for women with dense breasts.  He stresses that further evaluation of digital breast tomosynthesis in community practice is needed, and that several groups sponsored by the National Cancer Institutes are actively studying this issue, including the Breast Cancer Surveillance Consortium and the PROSPR (Population-based Research Optimizing Screening through Personalized Regimens) Network.

Read the study in the Annals of Internal Medicine here