Magnetic resonance imaging (MRI) significantly improves detection of contralateral breast cancer missed by mammography and clinical exam at or near the time of initial breast cancer diagnosis.
The findings come from a prospective, multicenter study involving almost 1,000 women recently diagnosed with unilateral breast cancer and with no mammographic or clinical exam abnormalities in the contralateral breast. All of the women underwent breast MRI. Women with images suggesting cancer received confirmatory biopsies. The absence of cancer on MRI was confirmed by biopsy, by the absence of findings on repeat imaging and clinical exams, or both at 1 year of follow-up.
MRI detected contralateral breast cancer in 30 of the women (3.1%) and was found to have a sensitivity, specificity, and negative predictive value of 91%, 88%, and 99%, respectively. Mean diameter of the tumors found was 10.9 mm, and detection was uninfluenced by breast density, menopausal status, or histologic tumor features.