The impact of presurgical magnetic resonance in early breast cancer: an observational study

The aim of this study was to evaluate the impact of presurgical breast magnetic resonance imaging (MRI) on the surgical management of selected patients with early-stage breast cancer who were candidates for BCT. The sample was built up according to the EUSOMA (European Society of Breast Cancer Specialists) recommendations enrolling women with unifocal unilateral early-stage breast carcinoma diagnosed by mammography, ultrasound (US) examination and in some cases also by histological analysis; all were scheduled for wider local excision. All eligible patients underwent presurgical breast MRI and findings were classified according to the BI-RADS system. In the presence of additional foci classified as BI-RADS 3-4, a targeted second-look US study was performed. If second-look US confirmed the presence of foci, needle biopsy was performed. Possible changes in the therapeutic approach resulting from preoperative MRI findings were decided upon by a multidisciplinary team. Outcome of histological examination of the surgical specimen and particularly analysis of tumor infiltration of the resection margins was the standard for determining the appropriateness of surgical strategy. A total of 123 patients underwent presurgical breast MRI. Additional foci were detected in 41.6% of patients, a greater local extension of the index lesion in 6.4%, whereas MRI confirmed local staging established by conventional imaging in 52%. However, 13.8% of additional foci were not confirmed by second-look and needle biopsy. More extensive surgery as a result of MRI findings was performed in 34.2%. This decision proved to be appropriate in 29.3% thus resulting in an over-treatment rate of 4.9%. Presurgical breast MRI resulted in confirmation of planned surgical strategy in 65.8% with an appropriateness rate of 54.5%. Surgical resection margins were positive for malignancy in 11.3% and repeated surgery was therefore required. Therapeutic strategy established on the basis of MRI was appropriate in 83.8% of cases. This study confirms the utility of MRI in presurgical workup of selected breast cancer patients. The results obtained suggest the importance of a sensitive tool such as MRI in the local staging of breast cancer before treatment planning.