Clinical Breast Examination
A doctor or nurse physically examines the breasts to check for lumps or irregularities.
When you should have it: Recommendations vary, but your doctor should manually examine your breasts when you are 20. By the time you are 30, you should have a manual exam every year.
What it can tell about you: Whether a lump or thickening is present.
Risks: Not all doctors are trained or skilled in this kind of examination. Lumps may be missed, or normal variations in breast tissue may be mistaken for tumors, leading to needless worry and expensive procedures.
An X-ray of the breast. The breast is squeezed between two plates to compress the tissue so that X-rays will pass through it.
When you should have it: Medical groups recommend that women 50 and over who have no lumps or other breast abnormalities have an annual mammogram. The evidence of a benefit is not as strong for women between 40 and 50. To be safe, many doctors recommend starting mammograms at 40 and having them annually.
What it can tell you: Suspicious findings come in two forms, calcifications and masses. Calcifications are calcium deposits; some are normal, but certain patterns of calcification may indicate a tumor and must be biopsied. A mass may be biopsied, or it can be examined with ultrasound to find out whether it is a cyst.
Risks: False positives and false negatives. On average, a woman has a 10 to 11 percent chance with each mammogram of a finding that requires further testing but turns out to be a false positive. Among abnormal mammograms, only 3 percent turn out to have detected cancer. But there are also false negatives: Overall, mammograms fail to detect 10 to 15 percent of cancers, according to Elizabeth Morris, M.D., an associate professor of radiology at Memorial Sloan-Kettering Cancer Center, in New York City.
An image of the breast that is made by exposing it to high-frequency sound waves.
When you should have it: To find out whether a suspicious lump is a solid mass or a fluid-filled cyst. Cysts are benign, except in rare cases, and can be drained with a needle. A solid mass may require a biopsy to determine if it is cancerous. Ultrasound may also be used to guide a needle biopsy.
What it can tell you: Besides showing whether a lump is a mass or a cyst, ultrasound is also being studied in women with dense breasts to see if it can help detect cancers that do not show up on mammograms.
Risks: False positives and false negatives.
Magnetic Resonance Imaging (MRI)
This test uses magnets and radio waves to create an exquisitely detailed image of breast tissue.
When you should have it: Women with risk factors (such as having a mother or a sister who had breast cancer) should consider a yearly scan in addition to a mammogram. A recent study found that MRI detected 80 percent of invasive growths, compared with 33 percent for mammography. If a mammogram has already found a tumor, MRI can help map the extent of the disease and look for other tumors. If a mammogram is questionable, MRI can help rule out a tumor.
What it can tell you: MRI is used at some centers to screen high-risk women. It is most helpful for those with dense breasts, where it works better than mammography.
Risks: Because of the high rate of false positives and the expense, MRI is not recommended for women with average risk.