Increasing Use of Preoperative Breast MRI for Women with Cancer

The use of preoperative breast magnetic resonance imaging (MRI) increased eight-fold over a 10-year period among women newly diagnosed with breast cancer in Ontario, Canada, according to an article published online by JAMA Oncology.1
Current guidelines recommend bilateral mammography as the primary imaging technique and, if necessary, preoperative ultrasonography. There has been growing use of preoperative breast MRI because of the potential that it might find hidden disease not seen with traditional breast imaging. However, breast MRI can lead to higher false-positive rates and it is expensive. Previous studies also suggest preoperative MRI fails to improve surgical outcomes, breast cancer recurrence rates or survival, according to study background information.
Angel Arnaout, M.D., M.Sc., of The Ottawa Hospital and the University of Ottawa, Ontario, Canada, and coauthors evaluated patterns of preoperative MRI use in new diagnosed breast cancer and the factors associated with it. The authors used administrative healthcare databases in Ontario over 14 geographic regions. Study participants included 53,015 women with primary operable breast cancer treated from 2003 to 2012.
The authors report that 14.8 percent of women (7,824 of 53,015) had preoperative MRI; most patients (65 percent) underwent breast-conserving surgery. The use of preoperative MRI increased eight-fold across all stages during the 10-year period, from 3 percent of patients newly diagnosed with breast cancer in 2003 to 24 percent of patients in 2012.
Patient-related factors associated with higher preoperative MRI use were younger age, higher socioeconomic status and higher comorbidity score. Health system and clinician factors related to increased preoperative MRI included surgery in a teaching hospital and fewer years of surgeon experience, according to the results.
Analyses suggest that preoperative breast MRI was associated with a higher likelihood of postdiagnosis breast imaging, breast biopsies and imaging to look for distant metastatic disease, as well as mastectomy, contralateral prophylactic mastectomy (when a healthy breast is also removed) and more than a 30-day wait for surgery
The authors suggest influences that may have contributed to the growth of preoperative MRI are increased availability of MRI scanners, rising patient demand and institutional pressure to use expensive capital equipment.
Even with a single-payer universal health insurance system, geographic variability existed in preoperative MRI use, according to the study.
Study limitations include the use of claims-based registry data, which do not include clinical indications for the preoperative MRI or any of the procedure outcomes. Administrative billing data also do not provide details on whether actual treatment decisions were changed based on test results.
“Irrespective of the reasons for increased pMRI [preoperative MRI] use, in an era of ever-increasing focus on cost containment in health care, consideration must also be given to the unintended consequences of those who undergo pMRI. The increased sensitivity of breast MRI is achieved at the cost of lower specificity; in practice, this translates into more confirmatory imaging and biopsies needed to rule out a diagnosis of cancer,” the authors write.
The authors conclude: “Preoperative breast MRI use has increased substantially in routine clinical practice and is associated with a significant increase in ancillary investigations, wait time to surgery, mastectomies and contralateral prophylactic mastectomies.”
In a related editorial2 Habib Rahbar, M.D., University of Washington, Seattle, and Constance D. Lehman, M.D., Ph.D., Massachusetts General Hospital, Boston, write: “This study adds to the growing body of evidence that the use of MRI in the preoperative setting is associated with more aggressive surgery of the affected breast. … It may be that advanced imaging, such as MRI, is unlikely to lead to better outcomes in the context of treatment paradigms developed in settings of conventional imaging. High-quality diagnostic mammography supported the transition from mastectomy to breast-conserving surgery and radiation for patients with unifocal disease. Similarly, MRI may support the next advance in treatment options that are more targeted to the individual patient’s disease burden. Because MRI can detect occult disease with high sensitivity, future research might explore its role in novel treatment approaches, such as whether it can identify patients for whom multiple lumpectomies for multicentric disease (in lieu of mastectomy) or for whom lumpectomy without radiation for unifocal low-risk disease are appropriate. It is this role in precision diagnostics and risk-stratification that advanced imaging techniques may hold the greatest promise, and for which MRI should be studied in future prospective trials.”
1. JAMA Oncol. Published online September 24, 2015. doi:10.1001/jamaoncol.2015.3018. 
2. JAMA Oncol. Published online September 24, 2015. doi:10.1001/jamaoncol.2015.3029.