Last updated: 11/24/2009

The purpose of screening mammography is breast cancer detection. A screening test, by definition, is used for patients without any signs or symptoms, in order to detect disease as early as possible. Many studies have shown that having regular mammograms...

increases a woman's chances of finding breast cancer in an early stage, when it is more likely to be curable. It has been estimated that a mammogram may find a cancer as much as two or three years before it can be felt. The American Cancer Society (ACS) guidelines recommend an annual screening mammogram for every woman of average risk beginning at age 40. Radiologists look specifically for the presence of microcalcifications and other abnormalities that can be associated with malignancy. New digital mammography and computer-aided reporting can automatically enhance and magnify the mammograms for easier finding of these tiny calcifications.

The highest risk factor for developing cancer is age. Some women are at an increased risk for developing breast cancer, such as those with a positive family history of the disease. Beginning screening mammography at a younger age may be recommended for these women.

Diagnostic mammography is used to evaluate an existing problem, such as a lump, discharge from the nipple, or unusual tenderness in one area. It is also done to evaluate further abnormalities that have been seen on screening mammograms. The radiologist normally views the films immediately and may ask for additional views such as a magnification view of one specific area. Additional studies such as an ultrasound of the breast may be performed as well to determine if the lesion is cystic or solid. Breast-specific positron emission tomography (PET) scans as well as an MRI (magnetic resonance imaging) may be ordered to further evaluate a tumor, but mammography is still the first choice in detecting small tumors on a screening basis.