The prognostic value of additional malignant lesions detected by magnetic resonance imaging versus mammography

Background Nodal positivity is correlated with a poorer prognosis in breast cancer. A study was composed to compare nodal positivity in patients with single versus multiple lesions found on magnetic resonance imaging (MRI) and mammogram (MMG). Methods A retrospective study of breast cancer patients undergoing MRI and MMG was performed. Nodal positivity was compared in patients with additional invasive lesions found on MRI versus single invasive lesions found on MRI and MMG. Results A total of 425 patients were included. The overall nodal positivity was 23.8%. Patients with single versus multiple malignant lesions had nodal positivity of 20.9% vs 31.1% ( P = .04). MRI detected multiple lesions in 120 patients, 80 of which were not detected by MMG (18.8%). Comparing single lesions with additional malignant lesions detected by MRI only, nodal positivity increased from 20.9% to 51.6% ( P = .0002). Conclusions Patients with additional invasive lesions on MRI had significantly higher nodal positivity than single invasive lesions. Hence, addition of MRI in early-stage breast cancer may have prognostic value because of detection of potential node-positive patients.