Background
Although there is no consensus on whether pre-operative MRI in women with breast cancer (BC) benefits surgical treatment, MRI continues to be used pre-operatively in practice. This meta-analysis examines the association between pre-operative MRI and surgical outcomes in BC.
Methods
A systematic review was performed to identify studies reporting quantitative data on pre-operative MRI and surgical outcomes (without restriction by type of surgery received or type of BC) and using a controlled design. Random-effects logistic regression calculated the pooled odds ratio (OR) for each surgical outcome (MRI versus no-MRI groups), and estimated ORs stratified by study-level age. Subgroup analysis was performed for invasive lobular cancer (ILC).
Results
Nineteen studies met eligibility criteria: 3 RCTs and 16 comparative studies that included newly diagnosed BC of any type except for 3 studies restricted to invasive lobular cancer (ILC). Primary analysis (85975 subjects) showed that pre-operative MRI was associated with increased odds of receiving mastectomy [OR 1.39 (1.23, 1.57); p<0.001]; similar findings were shown in analyses stratified by study-level median age. Secondary analyses did not find statistical evidence of an effect of MRI on the rates of re-excision, re-operation, or positive margins; however MRI was significantly associated with increased odds of receiving contralateral prophylactic mastectomy [OR 1.91 (1.25, 2.91); p= 0.003]. Subgroup analysis for ILC did not find any association between MRI and the odds of receiving mastectomy [OR 1.00 (0.75, 1.33); p= 0.988] or the odds of re-excision [OR 0.65 (0.35, 1.24); p= 0.192].
Conclusions
Pre-operative MRI is associated with increased odds of receiving ipsilateral mastectomy and contralateral prophylactic mastectomy as surgical treatment in newly diagnosed BC patients.