Prediction of Residual Malignancy After Excisional Biopsy for Breast Cancer With Suspicious Microcalcifications: Comparison of Mammography and Magnetic Resonance Imaging

BACKGROUND: Whether surgery should be performed after excisional biopsy based on mammography or magnetic resonance imaging (MRI) findings has not been evaluated for breast cancer with suspicious microcalcifications on mammography. This study investigated the ability of mammography and MRI to predict residual malignancy after excisional biopsy for suspicious microcalcifications and whether background parenchymal enhancement (BPE) influences the diagnostic performance of MRI. PATIENTS AND METHODS: Fifty-one patients with breast cancer who underwent excisional biopsy for suspicious microcalcifications between January 2009 and February 2019 were enrolled in this single-center retrospective study. Two expert readers independently evaluated the ability of mammography and MRI to predict residual malignancy at the surgical site. The diagnostic value of mammography and MRI was evaluated using histopathology as the standard. RESULTS: Thirty-two patients had residual malignancy. The average overall sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve for residual malignancy were 78.1%, 42.1%, 69.4%, 42.1%, 62.7%, and 0.601 for mammography and 81.2%, 57.8%, 76.4%, 57.8%, 73.5%, and 0.696 for MRI; the respective values for residual malignancy were 88.8%, 57.1%, 72.7%, 57.4%, 76.5%, and 0.73 in the low BPE group and 71.4%, 60%, 83.3%, 57.4%, 65.7%, and 0.657 in the high BPE group. CONCLUSIONS: MRI is more accurate than mammography for prediction of residual malignancy after excisional biopsy for breast cancer with suspicious microcalcifications. However, the BPE of MRI influences diagnostic performance, so careful assessment is needed in patients with moderate or marked BPE.