Which Patients With Newly Diagnosed Breast Cancer Benefit From Preoperative Magnetic Resonance Imaging?

The aim of this study was to identify the effectiveness and selective applications of preoperative magnetic resonance imaging (MRI) by investigating clinicopathologic factors of the index tumor with or without false lesions on MRI. Preoperative MRI is commonly performed in patients with newly diagnosed breast cancer, but its clinical significance is unclear. A total of 103 breast cancer patients who had undergone MRI or ultrasound followed by mastectomy were included in this retrospective investigation of pathologic, clinical, and imaging findings. MRI showed 29 false-positive lesions in 57 patients, 5 false-negative lesions in 5 patients, and 69 true-positive lesions in 103 patients. More false lesions on MRI were found in patients with more lesions on ultrasound, small-sized index tumors on ultrasound, or early-stage cancer. The sensitivity of MRI and ultrasound were 96.5% and 92.3% (P = 0.119), respectively, and the positive predictive value of them were 71.5% and 72.5% (P = 0.828), respectively. Preoperative MRI is more useful in patients with newly diagnosed breast cancer who have large-sized or more advanced cancers or fewer lesions on ultrasound.