According to the preliminary results of a study conducted in Italy, six of 18 breast cancers detected in high-risk women screened by clinical breast exam, ultrasonography, mammography, and magnetic resonance imaging (MRI) were detected only by MRI. These results were published in the journal Radiology.
Inherited mutations in two genes-BRCA1 and BRCA2-have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Alterations in these genes can be passed down through either the mother’s or the father’s side of the family.
Among women with a BRCA1 or BRCA2 mutation, an important goal of research is to identify treatments, screening tools, and behavioral changes that can reduce the risk of developing breast cancer or improve early detection of cancer. Some women with a BRCA1 or BRC2 mutation choose to undergo prophylactic (preventive) removal of the breasts and/or ovaries in order to reduce their risk of developing cancer, and others choose to undergo regular screening in order to detect cancer at an early stage.
In order to evaluate the ability of several breast cancer screening methods to detect breast cancer in women at high risk of the disease, researchers in Italy conducted a study among 278 women. Women were eligible if they were a BRCA1 or BRCA2 mutation carrier, a first-degree relative of a BRCA1 or BRCA2 mutation carrier, or at high-risk as a result of a strong family history of breast or ovarian cancer. A strong family history was defined as having three or more first- or second-degree relatives with any of the following: female breast cancer at a young age, male breast cancer at any age, or ovarian cancer at any age.
Study participants underwent annual screening with clinical breast exam, mammography, ultrasonography, and MRI.
- Breast cancer was found in 11 of 278 women at the first round of screening and in seven of 99 women at the second round of screening.
- Clinical breast exam detected 50% of the cancers, mammography detected 59% of the cancers, ultrasonography detected 65% of the cancers, and MRI detected 94% of the cancers.
- Of the 18 cancers detected, six were detected only by MRI.
- MRI was more likely to produce a false-positive result than some of the other tests. Among women with a positive screening test, the proportion who actually had cancer was 82% for clinical breast exam, 77% for mammography, 65% for ultrasonography, and 63% for MRI.
The researchers conclude that the addition of MRI to the screening regimen for women at high risk of breast cancer may increase breast cancer detection.
Reference: Sardanelli F, Podo F, D’Agnolo G et al. Multicenter comparative multimodality surveillance of women at genetic-familial high risk for breast cancer (HIBCRIT study): interim results. Radiology [early online publication]. 2007; January 23, 2007.