The American Cancer Society recently released recommendations for the use of magnetic resonance imaging (MRI)-in combination with mammography-for breast cancer screening. The guidelines-which were released in the March/April 2007 issue of CA-A Cancer Journal for Clinicians-recommend annual breast MRI in women at high risk of breast cancer.
The goal of cancer screening is to detect cancer at an early stage, when treatment will be most successful. For the early detection of breast cancer, the American Cancer Society recommends an annual mammogram and clinical breast exam starting at the age of 40. Younger women are advised to receive periodic clinical breast exams.
Receipt of regular screening mammography has been shown to reduce breast cancer mortality, and is an important success story in the fight against cancer. Nevertheless, mammography misses some cancers, and women at high risk of breast cancer may benefit from alternative approaches to screening. These alternative approaches may include initiation of screening at an earlier age; more frequent screening; or the combination of mammography with additional imaging procedures such as ultrasonography or MRI. Until recently, however, there was little evidence to support the use of any of these alternative approaches.
When considering new approaches to cancer screening, the potential risks must be weighed against the potential benefits. Benefits may include increased cancer detection, while risks may include a higher rate of false-positive test results (leading to unnecessary follow-up tests and anxiety) and higher cost.
The new guidelines from the American Cancer Society were prompted by several recent studies of MRI screening of women at high risk of breast cancer. While these studies found that the addition of MRI to mammography increased the frequency of false-positive test results compared to mammography alone, it also produced important improvements in breast cancer detection.
Based on these findings, the American Cancer Society recommends yearly screening with breast MRI in addition to mammography for the following high-risk groups of women:
- Women with a BRCA1 or BRCA2 mutation
- Women who have a first-degree relative (parent, sibling, child) with a BRCA1 or BRCA2 mutation, even if they have yet to be tested themselves
- Women who have a 20–25% or greater risk of breast cancer based on risk assessment tools
- Women who had radiation to the chest between the ages of 10 and 30 years
- Women who have Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome, or may have one of these syndromes based on a history in a first-degree relative
The American Cancer Society recommends against breast MRI screening in women with a lifetime risk of breast cancer of less than 15 percent. The optimal approach to the screening of women with an intermediate risk of breast cancer (lifetime risk between 15 and 20 percent) remains uncertain, and these women are encouraged to discuss their options with their physician.
In summary, the American Cancer Society recommends that women at high risk of breast cancer undergo yearly breast cancer screening with breast MRI in addition to mammography. The guidelines note that MRI screening “should be performed by experienced providers in facilities that provide MRI-guided biopsy for the follow up of any suspicious results.”
 American Cancer Society. American Cancer Society Guidelines for the Early Detection of Cancer. Available at: http://www.cancer.org/docroot/ped/content/ped_2_3x_acs_cancer_detection_guidelines_36.asp(Accessed April 2, 2007).