A costly tool used on nearly all mammograms does not increase cancer detection rates and should no longer be covered by Medicare, according to a recent editorial.
Joshua Fenton, a family physician and comparative effectiveness researcher, responds in the editorial to a study published in the same issue of the Journal of the American Medical Association Internal Medicine that announces findings from the largest study ever on computer-aided detection (CAD).
The Food and Drug Administration approved CAD nearly 20 years ago to help radiologists interpret screening mammograms by automatically marking potentially suspicious spots for further radiological review.
Use of the device with mammography did not improve the accuracy of the diagnosis, and its use may in fact result in missed cancer, according to the study led by Constance D. Lehman, currently director of breast imaging and co-director of the Avon Comprehensive Breast Evaluation Center at Massachusetts General Hospital in Boston.
“The study by Leyman, et al. provides evidence that CAD yields no clear benefits in a large, diverse US sample of women undergoing digital mammography,” Fenton writes. “Thus we should question whether society should continue to pay for CAD use.”
Using data from the Breast Cancer Surveillance Consortium, Leyman’s observational study looked at 323,973 women undergoing digital screening mammography in diverse US practices between 2003 and 2009. 271 radiologists from 66 facilities interpreted mammograms. Tumor registry data identified 3,159 breast cancers within one year of screening.
For the study, the researchers analyzed the mammography performance, including its sensitivity (the proportion of cancers positively detected), specificity (the proportion of accurate negative findings), the number of cancers detected during mammography, and those discovered within 12 months of a negative mammogram finding.
They found that screening performance was not improved with CAD on any one of the assessed metrics. In fact, they found that sensitivity was significantly decreased for mammograms interpreted with CAD among radiologists who interpreted results with and without the added technology.
In the editorial, Fenton, who also has published several research articles about the merits of CAD, says any potential positive effects of CAD may be undetectable in the context of digital mammography, which may improve the radiologist’s interpretation regardless of CAD.
Since Medicare agreed to cover the cost of CAD in 2000, its use has surged to over 90 percent of US mammograms. Leyman estimates that its prolific use adds up to more than $400 million per year, or $1 of every $10,000 spent on healthcare.
The results of the CAD research suggest that federal regulators and payers should base coverage determinations on facts, according to senior author of the study Diana Miglioretti, a biostatistics professor at the University of California, Davis.
“We need to make sure there is stronger evidence for new technologies before we start paying for them,” she says, “and before people are charged extra money for them.”
Source: UC Davis