If you are under 40, there are no general-consensus guidelines for you to follow concerning breast-cancer screening; you need to determine your own strategy. The American Cancer Society recommends a clinical breast exam every three years, but if you are at increased risk because of family history or lifestyle factors or just want to be especially cautious, ask your doctor or nurse to examine your breasts yearly -- or even at every visit. If you are comfortable doing so, examine your own breasts at the same time every month and be vigilant for changes in the way they feel. See a doctor immediately if you feel hardening or lumps.
Current research suggests that as a screening tool, mammograms are not useful in women under 40 and should be avoided unless you have symptoms like breast discharge or lumps that need diagnosis. Even then, because young women's dense breast tissue is often difficult to read accurately, another diagnostic tool, such as ultrasound, may be used as well.
For women between 40 and 50, the recommendations are more clear, although, again, there is no absolute consensus. The American Cancer Society recommends a mammogram every year; the National Cancer Institute, every one to two years. The age group for whom mammograms makes the most sense is 50-plus; women in this group should get regular screenings because their breast-cancer risk is significantly greater than younger women's. -- Anne M. Russell