Supplemental 3-D mammograms show value for dense breasts
Nearly half of U.S. women who undergo screening mammography have dense breast tissue, which reduces the screenings' ability to detect cancer and which is associated with moderately higher risk for developing cancer.
Adding tomosynthesis, or 3-D mammography, to routine biennial digital mammography screening among women with dense breasts could improve health outcomes – and at a reasonable cost relative to digital mammography screening alone. So suggests new research by physician-scientists at the University of Washington and Seattle Cancer Care Alliance. The findings appear online this month in the journal Radiology.
As of October 2014, 19 states' laws require physicians to inform patients if they have dense breasts and might benefit from supplemental screening; 15 other states are considering similar legislation.
However, the type of supplemental screening to be recommended remains unclear.
“We felt that this analysis would help inform timely policy and practice decisions,” said Dr. Christoph Lee, the study's lead author. “While screening ultrasound is currently touted as the additional test of choice for women with dense breasts, it requires significant increases in manpower and leads to a larger number of false positives. Digital breast tomosynthesis, in contrast to ultrasound, offers operational and ease-of-use advantages since it is an integrated part of newer-generation mammography units.”
For this study, researchers used the same breast-cancer simulation model that guided the U.S. Preventive Services Task Force's recommendations for breast-cancer screening. The team estimated the comparative clinical effectiveness and cost-effectiveness of biennial screening with both digital mammography and tomosynthesis versus digital mammography alone among U.S. women ages 50 to 74 with dense breasts. They used data from the National Cancer Institute’s Breast Cancer Surveillance Consortium, Medicare reimbursement rates, and medical literature.
They found that one breast-cancer death would be averted and 810 false-positive exams avoided per 2,000 women screened over 12 rounds of screening, and that the incremental cost per quality-adjusted life year gained by adding tomosynthesis to digital mammography screening was well below the established threshold for cost-effectiveness.
“Prior research has reported improved diagnostic accuracy with tomosynthesis, with both fewer false positives and higher cancer detection rates. However, until this study, we had little understanding of the impact of that improved performance on patient outcomes and costs," said Dr. Constance Lehman, UW chief of breast imaging and director of imaging at Seattle Cancer Care Alliance.
The study was supported in part by the National Cancer Institute (NCI) and in part by a Radiology Research Academic Fellowship, co-sponsored by GE Healthcare and the Association of University Radiologists. The sponsors had no role in the study concept, study design, data analysis, interpretation, or reporting of the results.
See additional information about a clinical trial in Seattle for women with dense breasts.