Maj. (Dr.) Shannon Lehr screens a set of mammogram X-rays in conjunction with a patient's office visit. Major Lehr is one of four general surgeons assigned to the 79th Surgical Operations Squadron at Malcolm Grow Medical Center. The American Cancer Society, a nationwide health organization, encourages women ages 20 and older to conduct breast self-examinations monthly. Breast examinations and screenings by a doctor are also recommended annually.