Brian Sprague, PhD

More than 40% of women undergoing mammography screening have normal breast tissue that is radiologically dense and may obscure the presence of breast cancer on a mammogram. Laws require that women with dense breast tissue be informed about the limitations of mammography, but there is no consensus regarding whether women with dense breast tissue should undergo additional breast cancer screening tests. Supplemental screening with whole breast ultrasound is one option, but prior studies have indicated a high rate of false positive exams that has limited enthusiasm. 

Now, new work by UVM Cancer Center investigators Brian Sprague, Sally Herschorn, Hannah Perry, and Donald Weaver, published in the journal Radiology, finds that supplemental ultrasound screening has favorable outcomes among women with dense breast tissue who also have other breast cancer risk factors.  

Women at high risk of invasive or advanced breast cancer according to established risk prediction models had high cancer detection rates on ultrasound screening after a negative mammogram, with an acceptably low rate of false positive exams.  In contrast, women with dense breasts who were at low or average risk of breast cancer had low cancer detection on ultrasound screening after a negative mammogram and a higher fraction of false positive exams. The collaborative study used data on over 30,000 ultrasound screening exams from three regional breast imaging registries (Vermont, San Francisco, Chicago) of the Breast Cancer Surveillance Consortium.  

The results of this study demonstrate the importance of determining breast cancer risk while counseling women with dense breasts regarding supplemental screening options.  According to Dr. Sprague, “These findings can help clinicians identify women with dense breasts who are good candidates for supplemental ultrasound screening.  Approximately 20% of women with dense breasts have high invasive or advanced breast cancer risk according to these risk models. These women are most likely to benefit from supplemental ultrasound screening.”

The breast cancer risk models used in the study were developed by Dr. Sprague and colleagues within the Breast Cancer Surveillance Consortium and are publicly available on the web and as iPhone and Android apps (https://www.bcsc-research.org/tools).  The risk models were developed using data from over 1 million women undergoing mammography screening at healthcare facilities participating in the Breast Cancer Surveillance Consortium, including data from over 200,000 women in the state of Vermont collected by the Vermont Breast Cancer Surveillance System led by Drs. Sprague, Herschorn, Perry, and Weaver. 

Future work will evaluate long-term outcomes for women undergoing supplemental ultrasound screening, including computer simulation modeling of breast cancer deaths averted. 

This study was conducted with collaborators at the University of California-San Francisco, the University of Illinois, the Fred Hutchinson Cancer Center, University of California-Davis, Harvard Medical School, and Kaiser Permanente Washington Health Research Institute.  The study was funded by the National Cancer Institute after initial pilot grant support from the UVM Larner College of Medicine and the Department of Surgery. 

Read full study in the journal of Radiology: https://pubs.rsna.org/doi/10.1148/radiol.232380

This research was also featured in the European Medical Journal and Let Life Happen.