Breast MRI surveillance in women with prior curative-intent therapy for breast cancer

Background: We sought to determine factors that predict the use of breast magnetic resonance imaging (MRI) surveillance in women previously treated for breast cancer and the incidence of in-breast recurrences and/or new cancers identified by MRI. Methods: We reviewed 141 patients who were treated between 2005 and 2008 who also underwent surveillance breast MRI following their treatment. Patient, tumor, treatment characteristics, and MRI findings were collected. Gail scores were calculated based on the patient's personal and family history prior to the breast cancer diagnosis. Data were compared using χ² and Fisher's exact test. Results: The average age of the study population was 51 (range 24-73). One hundred forty-one women underwent 202 surveillance breast MRIs during the study period. Sixteen of 141 (11%) required second look imaging, and six of 141 (4%) required biopsy of suspicious lesions. Two of the six were invasive breast cancers, while four were benign. Overall, the rate of new cancer detection on surveillance MRI during the study period was 0.9% (two of 202 imaging studies). Of the 71 women with evaluable Gail scores, the average lifetime risk score was 16.7%. Eight patients had BRCA mutations and three previously underwent irradiation for Hodgkin's lymphoma. Patient age, Gail score, tumor stage, grade, histology, receptor status, and surgical treatment were not predictive of MRI surveillance use. Conclusion: Prospective studies are needed to determine which patients may potentially benefit from breast MRI surveillance following curative-intent treatment. The lack of standardized guidelines may result in excessive or inappropriate use, unnecessary follow-up procedures, and a concomitant low yield.