SAN ANTONIO — The number of breast cancers detected in women with dense breasts was increased when those women who had a normal mammogram underwent an additional breast ultrasound screening, according to data presented at the 2014 San Antonio Breast Cancer Symposium, held Dec. 9–13.
“Having dense breasts substantially increases a woman’s risk of developing breast cancer,” said Jean M. Weigert, MD, FACR, a clinical radiologist and director of breast imaging at The Hospital of Central Connecticut in New Britain. “We found that among women with dense breasts, screening breast ultrasound detected a significant number of breast cancers not discovered by mammogram.”
In Connecticut, during four years of screening women with mammographically normal but dense breasts by breast ultrasound, the screening detected between three and four breast cancers per 1,000 women screened.
“This is important because it adds to the notion that breast cancer screening should be personalized, and that women with dense breasts should seriously consider adding a breast ultrasound to routine mammography,” continued Weigert.
On Oct. 1, 2009, Connecticut became the first state to enact legislation mandating that patients undergoing mammography be informed of their breast density and that those with mammographically dense breasts be told that further screening may be beneficial.
Weigert performed a retrospective analysis of data from two radiology practices in Connecticut from October 2009 to December 2013. Each year, approximately 30,000 screening mammograms were conducted at these practices, and the number of screening dense breast ultrasounds was 2,706, 3,351, 4,128, and 3,331 in years one through four, respectively. Breast ultrasound screens detected 11 breast cancers in year one, 11 in year two, 13 in year three, and 11 in year four.
Over the four years, the positive predictive value, which is the proportion of women with breast cancer among those with a positive breast ultrasound result, improved. It was 7.1 percent in year one, 6.1 percent in year two, 8.1 percent in year three, and 17.2 percent in year four.
“Over the four years, we have learned how to better identify those breast ultrasound abnormalities that may truly be cancer,” said Weigert. “The positive predictive value for mammography is about 20 to 30 percent. So we are getting close to this with breast ultrasound now that we are more experienced.”
Weigert declares no conflicts of interest.