Background and Objectives
Preoperative breast magnetic resonance imaging (B‐MRI) staging in newly diagnosed breast cancer increases detection of synchronous contralateral findings, but may result in false‐positive outcomes. This study objective was to identify women more likely of having mammographically occult, MRI detected contralateral breast cancer (CBC).
Methods
We performed a retrospective review of patients who had preoperative B‐MRI prior to surgery from 2010 to 2015 and collected patient imaging and clinicopathologic data. Multivariate logistic regression was used to identify predictors of CBC.
Results
MRI resulted in contralateral findings in 201 of 1894 patients (10.6%). Overall 3.2% (60 of 1894) had synchronous CBC detected on B‐MRI. The majority of CBCs (n = 60) were stage 0 or IA (85.0%), hormone receptor positive (94.9%), human epidermal growth factor receptor 2 (HER2/neu) negative (89.7%), and low/intermediate pathological grade (87.2%). Women more likely to have CBC were older (P < .001), had lobular index cancer (P = .03), and estrogen receptor (ER)+ (P = .027) or progesterone receptor (PR)+ (P = .002) tumors. On multivariate analysis (receiver operating characteristic curve area = 0.75), PR + status (P = .022), and older age (P = .004) were predictive of CBC.
Conclusions
Preoperative MRI is most effective in detecting early stage, hormone receptor‐positive CBC in older women.