A new article discusses the evidentiary support for the recent changes made by the American Cancer Society in its recommendations for breast cancer screening. In addition to modifying the suggested ages for annual and biannual mammography, the new recommendations also focus on patient preference in decision making.
The authors discuss the subtle but very important difference between the sensitivity and false positive rates for mammography. Among asymptomatic women, even though approximately 84% of breast cancers are detected by mammography, approximately 95% of all positive mammograms are false positives. The authors note that the emphasis on patient involvement in making health decisions could be problematic due to the difficulty patients may have in understanding this technical distinction.
"Our goal was to caution asymptomatic women that positive mammograms are vastly more likely to be false positives than actual evidence of cancer," said Dr. William Skorupski, co-author of the Significance article. "For most women, a false positive mammogram is about 19 times more likely than a true positive," added co-author Dr. Howard Wainer.