Mammography

Mammograms are X-ray images of the breasts used to screen for breast cancer. Mammograms play a key role in early detection of breast cancer. During a mammogram, the breasts are compressed between two firm surfaces to spread out the breast tissue. Then an X-ray captures black-and-white images of the breasts that are displayed on a computer screen and examined by radiologists.

Mammography can be used either for screening or for diagnostic purposes in evaluating a breast lump:

• Screening mammography. Screening mammography is used to detect breast changes in women who have no signs or symptoms or new breast abnormalities. The goal is to detect cancer before clinical signs are noticeable.

• Diagnostic mammography. Diagnostic mammography is used to investigate suspicious breast changes, such as a new breast lump, breast pain, an unusual skin appearance, nipple thickening or nipple discharge. It's also used to evaluate abnormal findings on a screening mammogram. A diagnostic mammogram includes additional mammogram images.

Some general guidelines for when to begin screening mammography include:

• Women with an average risk of breast cancer. Many women begin mammograms at age 40 and have them every one to two years. Professional groups differ on their recommendations. The American Cancer Society advises women with an average risk to begin screening mammograms yearly at age 45 until age 54, and then continue every two years for at least the next 10 years. The U.S. Preventive Services Task Force recommends women start screening every two years starting at age 50 until age 74. However, these groups agree that women can choose to be screened starting at age 40.

• Women with a high risk of breast cancer. Women with a high risk of breast cancer may benefit by beginning screening mammograms before age 40. Talk to your doctor about evaluating your individual risk of breast cancer. Your risk factors, such as a family history of breast cancer or a history of precancerous breast lesions, may lead your doctor to recommend magnetic resonance imaging (MRI) in combination with mammograms.