The Association of Preoperative Magnetic Resonance Imaging (MRI) with Surgical Management in Patients with Early-Stage Breast Cancer

Introduction: The rate of mastectomy in lumpectomy-eligible patients with unilateral breast cancer is increasing. We sought to investigate the association between magnetic resonance imaging (MRI) and surgical management of patients with early-stage breast cancer by comparing the rate of mastectomy as first surgery in patients with and without preoperative MRI. Methods: A bi-institutional retrospective study included patients diagnosed between 2016 and 2020. Lumpectomy-eligible patients with in situ and invasive cancer were included. Those receiving preoperative therapy, MRI before diagnosis, or with known bilateral cancer were excluded. The risk factors for bilateral and multicentric disease were accounted for. Fisher's exact andchi-square tests comparedcategorical variables, Wilcoxontwo-sample testanalyzed continuous variables, andmultivariate analyses were performed with Poisson regression. Results: Four hundred twenty-eight participants met inclusion criteria. Patientswhoreceived MRI were younger (58 versus 67 y; P < 0.001) and had denser breasts (group 3 or 4; 61% versus 25%; P < 0.001). Mastectomy rate was twice as high in patients undergoing MRI (32% versus 15%, rate ratio 2.16; P < 0.001), which remained significant in multivariate analysis (rate ratio 2.0; P< 0.001). Contralateral mastectomy (12% versus 4%; P = 0.466) and reexcision (13% versus 12%; P = 0.519) rates were similar. Time to surgery was greater in those receiving MRI alone and MRI biopsy (34 [no MRI] versus 45 [MRI] versus 62 [MRI biopsy]; P < 0.001 for both). Conclusions: MRI receipt is associated with a doubled rate of mastectomy in lumpectomyeligible patients. Future work is needed to standardize patient selection for MRI to those with the highest likelihood of having additional undiagnosed disease. (c) 2022 Elsevier Inc. All rights reserved.