Histopathologic Correlation of Residual Mammographic Microcalcifications After Neoadjuvant Chemotherapy for Locally Advanced Breast Cancer

This study was designed to determine the histopathologic correlation at surgery of residual mammographic calcifications in patients after neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC). This single-institution, retrospective study was approved by the Institutional Review Board and was Health Insurance Portability and Accountability act compliant. Women with LABC who underwent NAC between January 1, 2004 and December 31, 2008 and had mammography performed before and after NAC available for review were included in this study. The extent of microcalcifications associated with cancer before and after the completion of NAC was correlated with histopathology and biomarker status. Of 494 patients who met the inclusion criteria, 106 demonstrated microcalcifications on pre-, post-chemotherapy, or both sets of mammograms and were included in this study. Of 106 women, 31 (29 %) had invasive ductal carcinoma (IDC) and 60 (57 %) had both IDC and ductal carcinoma in situ (DCIS). Microcalcifications decreased or remained stable in 76 (72 %) patients after completion of NAC. Correlation of microcalcifications with histopathology after NAC showed that 43 (40.6 %) patients had tumors associated with benign pathology. Of 32 patients with pathologic complete response, calcifications were associated with DCIS in 9 (9 %) and benign findings in 21 (22 %). The proportion of residual malignant calcifications was higher in ER+ versus ER- patients after NAC. The extent of calcifications on mammography following NAC does not correlate with the extent of residual disease in up to 22 % of women; this information may impact surgical planning in subsets of women with breast cancer.