In a study of 1.3 million women, ages 40 to 74, having a false positive on a screening mammogram was associated with a slightly increased chance that the woman would eventually develop breast cancer. The extra risk seemed to be independent of the density of her breasts. Lester Lefkowitz/Getty Images hide caption

toggle caption Lester Lefkowitz/Getty Images

A woman's health history and tolerance for different kinds of risks should have a legitimate role in determining the timing of when she starts and stops getting screening mammograms, some leading doctors say. Sally Elford/Ikon Images/Getty Images hide caption

toggle caption Sally Elford/Ikon Images/Getty Images

The American Cancer Society has pushed back the age at which most women should begin having mammograms to 45. iStockphoto hide caption

toggle caption iStockphoto

Lateral mammogram showing a tumor iStockphoto hide caption

toggle caption iStockphoto

Science-based guidelines say there's no benefit to getting an EKG of heart activity before routine cataract surgery — even if the patient is old. But most doctors order such tests anyway. Bull's Eye/ImageZoo/Corbis hide caption

toggle caption Bull's Eye/ImageZoo/Corbis

Betty Daniel gets a routine yearly mammogram from mammography tech Stella Palmer at Mount Sinai Hospital in Chicago in 2012. Heather Charles/MCT/Landov hide caption

toggle caption Heather Charles/MCT/Landov

A mammographer prepares a screen-film mammography test for patient Alicia Maldonado at a hospital in Los Angeles. Damian Dovarganes/AP hide caption

toggle caption Damian Dovarganes/AP

Mammograms may pose a particular risk to women with genetic mutations that predispose them to breast cancer. Bill Branson/National Cancer Institute hide caption

toggle caption Bill Branson/National Cancer Institute

NPR thanks our sponsors

Become an NPR sponsor