Mammography plays a key role in the early detection of breast cancer. It can reveal the presence of cancer long before it can be felt or cause symptoms. Current guidelines from the American Cancer Society (ACS) and the American College of Radiology (ACR) recommend screening mammography every year for women, beginning at age 40. Research shows that annual mammograms lead to the early detection of breast cancers, when they are small and more easily treated and cured. Women who have had breast cancer or are at higher risk due to a family history of the disease should talk to their doctor about when and how often they should be screened.