Ten percent of women who have been diagnosed with cancer in one breast also have cancer in the other, and magnetic resonance imaging scans can detect cancer that has been missed by mammography or clinical examination, according to a report in the March 29 New England Journal of Medicine.
In a study funded by the National Cancer Institute, MRIs detected cancer in the second breasts of 30 of 969 (3.1%) women who had been diagnosed with unilateral breast cancer after mammography and clinical examination between April 1, 2003, and June 10, 2004. In all, 135 biopsies were recommended on the basis of MRIs, and 121 were carried out with 30 procedures finding cancer (24.8%).
In addition to finding previously undetected cancers, the study authors wrote that the MRI could provide useful information to women considering a double mastectomy when only one cancer is found. The authors also note that the cost of an MRI precludes its widespread use in the general population, but appears to improve the detection of women at increased risk.
In related news, in CA: A Cancer Journal for Clinicians, the American Cancer Society released a new recommendation calling for the use of MRI screening for women who have a 20% or greater lifetime risk of breast cancer based on family history of breast or ovarian cancer or who have been treated with Hodgkins disease. -- by Andis Robeznieks