More than two-thirds of breast cancer deaths occurred in younger women who do not have regular mammograms, a U.S. study said Monday, refuting a 2009 recommendation that discouraged routine screenings for women under 50 and recommends only biennial screenings of those aged between 50 and 74. Harvard Medical School Professor of Surgery Blake Cady and his colleagues identified 7,301 women diagnosed with breast cancer between 1990 and 1999 and followed their cases through 2007. Of the 609 women who died from breast cancer, 71 percent were women who had not undergone regular breast cancer screenings, or were never screened prior to diagnosis, the researchers said. Moreover, 50 percent of the breast cancer deaths occurred in women under the age of 50, while only 13 percent were in women aged 70 years or older. For women who died of breast cancer, the median age at diagnosis was 49; for those dying of any other cause, the median age at diagnosis was 72. The findings indicated that women under 50 are a primary group in which greater screening compliance would provide the greatest benefit, the researchers said in the journal Cancer. \"These findings should quiet those who argue that women age 40 to 49 do not need regular mammography screening. In fact, these women need annual screening -- as do all women 40 and older. This is the message physicians should be promoting,\" Barbara Monsees, chair of the American College of Radiology Breast Imaging Commission, said in a statement. \"Breast cancer treatment has come a long way, but, as this study demonstrates, these advances have not negated the value of, or the need for early detection. This is especially true for younger women, who tend to have faster growing tumors,\" Monsees said. In 2009, the U.S. Preventive Services Task Force, an independent panel of experts that makes recommendations about health practices, said that before having a mammogram, women younger than 50 should talk to their doctors about the risks and benefits of the test, and then decide if they want to be screened. For women aged 50 to 74, the panel recommended routine mammograms every two years.