Despite updated U.S. recommendations that women wait until 50 for routine breast cancer screenings, women in their 40s are still being tested, researchers say. Dr. Lauren D. Block, a clinical fellow in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine in Baltimore, said in 2009, the U.S. Preventive Services Task Force sifted through the research and recommended women ages 50-74 should undergo mammograms every two years. Those between the ages of 40-49 without a family history of breast cancer should discuss the risks and benefits of routine screening mammography with their physicians to make individual decisions, Block said. "Patients -- and likely their providers -- appear hesitant to change their behavior, even in light of evidence that routine screening in younger women carries substantial risk of false positives and unnecessary further imaging and biopsies," Block said in a statement. "Women have been bombarded with the message 'mammograms save lives,' so they want them no matter what." Routine breast cancer screening improves the detection of cancer in young women, but reduces mortality risk by a very small percentage, Block said. The studies said mammograms conducted on women younger than age 50 are more likely to result in over-diagnosis, unnecessary treatment -- including biopsies, lumpectomies and mastectomies -- and weeks of radiation and potentially toxic drugs, Block said. Block and colleagues analyzed mammogram use data from Behavioral Risk Factor Surveillance System surveys administered in 2006, 2008 and 2010 by state health departments. Data from 484,296 women ages 40-74 were collected. Among women in their 40s, 53 percent reported having a mammogram in the past year in 2006 and 2008, compared with 65 percent of women ages 50 to 74. The study, published online in the Journal of General Internal Medicine, found in 2010, after the new recommendations were in effect, 52 percent of younger women and 62 percent of older women reported having a mammogram.