Breast Cancer Screening
Test results may appear to be abnormal even though no cancer is present. A false-positive test result (one that shows there is cancer when there really isn't) can cause anxiety and is usually followed by more tests (such as a biopsy), which also have risks. In fact, 80 to 90 percent of all abnormal mammograms are false-positives.
Most abnormal test results from breast cancer screenings turn out not to be cancer. False-positives are more common in:
- Younger women
- Women who have had previous breast biopsies
- Women with a family history of breast cancer
- Women who take hormones, such as estrogen and progesterone.
The skill of the radiologist also can affect the chance of a false-positive result.
Being exposed to radiation is a risk factor for breast cancer. The risk of developing the disease from mammograms is greater with higher doses of radiation and in younger women. For women older than 40, the benefits of an annual mammogram to screen for breast cancer may be greater than the risks from radiation exposure.