Most women should start regular breast cancer screening at age 50, not 40, according to new guidelines released Monday by an influential group that provides guidance to doctors, insurance companies and policy makers. The new recommendations reverse longstanding guidelines and are aimed at reducing harm from overtreatment, the group says. It also says women age 50 to 74 should have mammograms less frequently — every two years, rather than every year. And it said doctors should stop teaching women to examine their breasts on a regular basis. Just seven years ago, the same group, the United States Preventive Services Task Force, with different members, recommended that women have mammograms every one to two years starting at age 40. It found too little evidence to take a stand on breast self-examinations. The group’s new guidelines, which are different from those of some professional and advocacy organizations, are published online in The Annals of Internal Medicine They are likely to touch off yet another round of controversy over the benefits of screening for breast cancer. Dr. Diana Petitti, vice chairwoman of the task force and a professor of biomedical informatics at Arizona State University, said the guidelines were based on new data and analyses and were aimed at reducing the potential harm from overscreening. While many women do not think a screening test can be harmful, medical experts say the risks are real. They include unnecessary tests, like biopsies that can create extreme anxiety. And mammograms can find cancers that are better off not found. Some cancers grow so slowly that they never would be noticed in a woman’s lifetime. When they are found, women end up being treated unnecessarily. Continua…