Preoperative Breast MRI for Extent-of-Disease Evaluation Following New Breast Cancer Diagnosis: A Retrospective Cohort Study.

Abstract

Despite potential benefits for surgical planning, prior studies have demonstrated disparities in the use of preoperative breast MRI, raising concerns about equitable access to this imaging tool. In this study, the authors assessed how the rates of preoperative breast MRI use vary by patient sociodemographic and clinical factors and evaluated MRI benefits in this context. This was a retrospective cohort studying including all patients who underwent breast surgery after a new breast cancer diagnosis at a tertiary care multisite academic institution between July 1, 2016, and December 31, 2022 (n = 1,792). Patient characteristics were compared between the patients who did (n = 992) and did not (n = 800) undergo MRI for disease extent evaluation using the χ² test. MRI examinations were completed more frequently in patients 50 years or younger and those 51 to 70 years of age compared with those older than 70 years (77% and 50% vs 25%, P < .001) and in those of white and other races than those of black race (55% and 62% vs 44%, P < .001). The rate of MRI increased with increasing breast density (P < .001) and higher tumor stage (P < .001). It was also influenced by receptor status and histology, with the highest utilization in patients with Her2⁺ enriched disease (P < .001) and those with invasive lobular carcinoma (P < .001). Among patients who underwent preoperative MRI, 51.5% were found to have additional suspicious lesions, and 69.1% of these patients underwent image-guided biopsy (26.6% malignant, 16.6% high risk). Patients who underwent preoperative MRI underwent mastectomy more commonly than those who did not (49% vs 31%, P < .001) but were significantly less likely to require reexcision (8% vs 14%, P < .001). The present results suggest that preoperative MRI improves surgical planning by detecting additional lesions and decreasing the need for reexcision but is also associated with higher mastectomy rates. Utilization varied significantly by age, race, tumor features, and breast density, highlighting sociodemographic and clinical disparities. These findings underscore the need for targeted efforts to ensure equitable access and to develop guidelines.