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

itoggle 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

itoggle caption Bill Branson/National Cancer Institute

Radiologist Gerald Iba checks mammograms at The Elizabeth Center for Cancer Detection in Los Angeles in May 2010. Damian Dovarganes/AP hide caption

itoggle caption Damian Dovarganes/AP

Karen Lindsfor, a professor of radiology and chief of breast imaging at the University of California, Davis Medical Center, examines the mammogram of a patient with heterogeneously dense breast tissue. Lindfors is among those doctors who say there was insufficient evidence to support the idea that additional screenings would detect cancers earlier. Rich Pedroncelli/AP hide caption

itoggle caption Rich Pedroncelli/AP

The problem of breast cancer overdiagnosis with mammograms is similar to the dilemma faced by men diagnosed with prostate cancer because of a PSA test. Damian Dovarganes/AP hide caption

itoggle caption Damian Dovarganes/AP