In sharp contrast to the recommendations of the American Medical Association and the National Cancer Institute, a new study says that mammograms offer few lifesaving benefits for women in their 40s. The research, published in tomorrow's issue of the Journal of The American Medical Association and conducted by a team at the University of California at San Francisco, backs up the National Cancer Institute, which last year stopped recommending that women in their 40s get regular mammograms. "At the time the NCI changed its policy, people said it was a penny-pinching approach to preventive care," saysTIME Health Care reporter Janice Castro. "Now the organization is vindicated." But today, neither the American Medical Association nor the American Cancer Society said they would change their longstanding policies, which say that women in that age group get a mammogram every year or two. The University of California study found that regular mammograms reduce the risk of dying of breast cancer for women over 50.