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