Does every woman presenting with malignant calcifications require a post lumpectomy mammogram?

Successful breast-conserving surgery (BCS) followed by radiation therapy (XRT) is dependent on complete removal of the cancer with clear surgical margins, providing survival rates equivalent to those observed following mastectomy. In patients who have cancers presenting with microcalcifications, post lumpectomy mammograms (PLM) prior to radiation (XRT) can be performed to ensure that no cancer has been left behind. The purpose of this study was to assess the benefit of PLM in patients with malignant breast tumors presenting with microcalcifications.

In this IRB-approved retrospective study, we reviewed medical records for patients with breast cancers presenting with microcalcifications who underwent BCS between February 2008 and June 2013. 198 patients who had a PLM prior to XRT for cancers presenting with microcalcifications were included.

Histopathology of the initial lumpectomy revealed invasive carcinoma in 78/198 (39.4%) and DCIS alone in 120/198 (60.6%). 114/198 (58%) patients had negative surgical margins. 7/114 (6%) patients with negative margins had positive PLM and re-excisions that were positive for malignancy: sensitivity 88%, specificity 95%, PPV 58%, NPV 99%. 84/198 patients had positive surgical margins. The diagnostic performance of PLM in this group was: sensitivity 55%, specificity 71%, PPV 66%, NPV 61%.

PLM plays an important role in the evaluation of patients undergoing breast conservation for breast cancer presenting with microcalcifications. Residual malignancy was detected on positive PLM in 6% of patients with negative margins.