Rethinking Preoperative MRI in Early Breast Cancer: Who Truly Benefits?

OBJECTIVE: In light of existing evidence on the use of preoperative magnetic resonance imaging (MRI) in breast cancer (BC) patients undergoing upfront surgery, this study evaluated whether adding MRI to conventional imaging improved the definition of disease extent, subsequent surgical management, and survival outcomes. MATERIALS AND METHODS: This retrospective study reviewed patients with stage I-II BC who underwent upfront surgery between January 2014 and September 2025. Patients were divided into an MRI cohort and a non-MRI cohort, and clinicopathologic characteristics, the diagnostic performance of ultrasound and MRI in detecting additional malignant foci, the type of surgery, and recurrence during follow-up were compared. RESULTS: A total of 261 patients were included, with 149 assigned to the MRI cohort and 112 to the non-MRI cohort. Patients in the MRI group were younger, more often premenopausal, and more likely to have dense breasts. MRI detected additional malignant foci, including ductal carcinoma in situ and invasive carcinoma, in 38 patients of 149 (25.48%). MRI findings led to the conversion from planned lumpectomy to mastectomy in 16/149 patients (10.7%), mainly due to the detection of new multicentric disease. With a median follow-up of 30-36 months, there has been no significant difference between the two cohorts concerning local recurrence (p>0.99) or distant metastasis (p = 0.39). CONCLUSION: Preoperative MRI occasionally changed surgical plans but offered no diagnostic advantage over standard imaging, supporting its selective rather than routine use in upfront BC surgery.