human
My doctor says I should get a mammogram every year. Why is that necessary?
assistant
A mammogram is a screening test for breast cancer. It can detect tumors in the breast before they are large enough to be felt by a woman or her doctor. If you have a family history of breast cancer, or if you have any risk factors such as being overweight, having dense breasts, or being over age 40, then your doctor may recommend more frequent screening.