Preoperative axillary lymph node evaluation in breast cancer patients by breast magnetic resonance imaging (MRI): Can breast MRI exclude advanced nodal disease?

Objectives: To evaluate the diagnostic performance of breast magnetic resonance imaging (MRI) in preoperative evaluation of axillary lymph node metastasis (ALNM) in breast cancer patients and to assess whether breast MRI can be used to exclude advanced nodal disease. Methods: A total of 425 patients were included in this study and breast MRI findings were retrospectively reviewed. The diagnostic performance of breast MRI for diagnosis of ALNM was evaluated in all patients, patients with neoadjuvant chemotherapy (NAC), and those without NAC (no-NAC). We evaluated whether negative MRI findings (cN0) can exclude advanced nodal disease (pN2-pN3) using the negative predictive value (NPV) in each group. Results: The sensitivity and NPV of breast MRI in evaluation of ALNM was 51.3 % (60/117) and 83.3 % (284/341), respectively. For cN0 cases on MRI, pN2-pN3 manifested in 1.8 % (6/341) of the overall patients, 0.4 % (1/257) of the no-NAC group, and 6 % (5/84) of the NAC group. The NPV of negative MRI findings for exclusion of pN2-pN3 was higher for the no-NAC group than for the NAC group (99.6 % vs. 94.0 %, p = 0.039). Conclusions: Negative MRI findings (cN0) can exclude the presence of advanced nodal disease with an NPV of 99.6 % in the no-NAC group. Key points: • Breast MRI can be used to exclude advanced nodal disease (pN2-3). • Negative MRI allows breast cancer patients to avoid unnecessary axillary surgery (98.2 %). • Negative MRI findings exclude 99.6 % of pN2-pN3 in the no-NAC group. • Negative MRI findings exclude 96.0 % of pN2-pN3 in the NAC group.