L. S. Sparber1, R. S. Chamberlain1,2,3 1Saint Barnabas Medical Center,Deptarment Of Surgery,Livingston, NJ, USA 2Saint George’s University,School Of Medicine,St. George’s, , Grenada 3New Jersey Medical School,Rutgers University – Department Of Surgery,Newark, NJ, USA
Introduction: For over three decades, screening mammography has played a central role in the early detection of in situ breast tumors in the United States. More recently, breast magnetic resonance imaging (MRI) has emerged as a potentially more sensitive imaging modality than traditional mammography, but whether its use should be limited to adjunct screening for those at high risk or be universally utilized remains controversial. While breast MRI undoubtedly detects subtler breast abnormalities, it is unclear whether this has resulted in an improvement in treatment decisions for patients with Ductal Carcinoma in situ (DCIS).
Methods: A comprehensive search for all published clinical studies on the use of MRI and its impact on DCIS management (2010-2014) was conducted using PubMed and Google Scholar. The search focused on the value of MRI to guide treatment strategies, including mastectomy rates, re-excision rates and the overall benefit of this added imaging modality. Keywords searched included: “breast MRI”, “mastectomy”, “DCIS”, “Ductal Carcinoma in situ”, and “surgical planning” in all possible combinations.
Results: Six studies involving 3,296 patients have been published (Table 1). Pilewskie et al (2014) reported the largest study involving 2,321 DCIS patients (596 DCIS patients in MRI group; 1,725 patients in non-MRI group). Within this group, 904 DCIS patients underwent radiation therapy [RT]; and 1,391 patients did not. In the non-RT subgroup there was no association with the performance of an MRI and lower loco regional recurrence rates (p = 0.28). Three additional studies analyzed the impact of MRI on DCIS mastectomy rates, with Allen et al reporting no significant difference in mastectomy rates if an MRI was performed (p = .62). In contrast, Itakura et al reported increased mastectomy rates in patients undergoing preoperative MRI (p < .001). Re-excision rates were investigated in three studies, and preoperative performance of an MRI did not statistically impact these rates favorably or negatively. Pilewskie et al, demonstrated that breast conserving surgery was more successful in the non-MRI group (p = .06), whereas Allen et al and Kropcho et al found the results to not be statistically significant (p = .41 and p = .414, respectively). Across all studies, preoperative MRI was judged not routinely beneficial in DCIS patients.
Conclusion: Breast MRI is associated with an increased sensitivity compared to other breast imaging technologies; however, it does not appear to improve clinical outcomes in patients with DCIS when added to conventional breast assessment. Moreover, routine breast MRI in DCIS may contribute to an increase in unnecessary mastectomies.
