More bang for the buck: Screening with tomosynthesis and mammography is cost-effective

Biennial breast cancer screening that combines digital mammography and tomosynthesis not only increases breast cancer detection in women with dense breasts compared with mammography alone, it does so while remaining cost-effective, according to a study published online Oct. 28 in Radiology.

A research group headed by Christoph I. Lee, MD, of the University of Washington School of Medicine in Seattle, examined the comparative clinical effectiveness and cost-effectiveness of paring biennial digital mammography with additional tomosynthesis (versus digital mammography alone) among U.S. women between 50 and 74 years old, all with dense breasts.

While mammography is the most effective method of screening for breast cancer, it is less accurate in women with dense breasts because the dense tissue can obscure cancers.

“Moreover, dense breasts compared to average density breasts are associated with a moderate to high relative risk for developing breast cancer independent of the masking effect,” wrote Lee and colleagues. “Given that nearly half of the U.S. screening population has dense breasts, an increasingly large number of woman may be encouraged to consider supplemental screening beyond conventional mammography.”

Screening MR is one of the more sensitive imaging tests for detecting cancer, but it also costs more and requires intravenous contrast injections, while tomosynthesis has recently shown potential at improving cancer detection in women with dense breasts without significantly raising the cost burden.

“With tomosynthesis, mammographic projections are acquired at different angles to generate a three-dimensional image of the breast during the standard mammographic compression,” the researchers explained.

Lee and associates found that the cost per quality-adjusted life year (QALY) gained by adding tomosynthesis to digital mammography screening was $53,893. The threshold of cost-effectiveness is generally considered to be $100,000 per QALY.

A total of 405 false positives were avoided and 0.5 deaths were prevented with adding tomosynthesis to the biennial digital mammography.

“In contrast to supplemental screening US and MR imaging, which are associated with increases in both cancer detection and false positive findings, adjunct tomosynthesis has been shown to increase cancer detection while decreasing false-positive findings,” Lee and colleagues wrote.

The study utilized a breast cancer-simulation model developed by the University of Wisconsin that explored ramifications of alternative programs of breast cancer screening and treatment.

The model simulated the life history of women in the U.S. by using four interacting processes: breast cancer natural history, detection, treatment, and competing-cause mortality.

Calibrated on the basis of real-world observations, the model treated treatment effectiveness as a function of age, estrogen receptor status, calendar year and stage at diagnosis. The model used data from the National Cancer Institute’s Breast Cancer Surveillance Consortium, Medicare reimbursement rates and other available data.