Computer-aided detection (CAD) software designed to improve how radiologists interpret mammograms may actually make readings less accurate, according to new research conducted by investigators at UC Davis.

CAD was approved by the U.S. Food & Drug Administration in 1998 and has been incorporated into many mammography imaging practices.

"Within three years of FDA approval, 10 percent of the mammography facilities in the country were using CAD," said lead researcher Joshua J. Fenton, assistant professor of family and community medicine at UC Davis. "There had been no large- scale, community-based review of CAD efficacy despite the rapid adoption of this technology."

The new study, funded by the National Cancer Institute, the U.S. Agency for Healthcare Research and Quality and the American Cancer Society, showed that women who received screening mammograms at centers using CAD software were more likely to be told their mammograms were abnormal and thus more likely to undergo biopsies to rule out breast cancer. The authors of the study estimate that for every additional woman diagnosed with breast cancer on the basis of CAD, 156 women were falsely recalled for more tests and 14 had unnecessary biopsies to exclude cancer.