Is postexcision, preradiation mammogram necessary in patients after breast-conserving surgery with negative margins

Background: In women with breast cancer and calcifications, controversy exists over the need for postexcision/lumpectomy, preradiation mammogram (PEM) after breast-conserving surgery (BCS). Further, the need for excision of remaining or suspicious calcifications after PEM when surgical margins are negative is unclear. We sought to characterize the utility of PEM hypothesizing that its value in directing the need for additional surgery is minimized after achieving negative surgical margins. Methods: We identified 524 women with breast cancer and calcifications treated with BCS with negative margins between 1996 and 2011. Results: PEM was performed in 112 of 524 (21 %) women, with residual calcifications identified in 10 of 112 (9 %); of these, 2 of 112 (1.8 %) had residual disease. Local recurrence occurred in 4 of 112 (4 %) patients, none of whom had residual calcifications identified on PEM. The remaining 412 of 524 (79 %) women did not have PEM but had a postradiation mammogram 6 to 12 months after treatment identifying calcifications in 19 (5 %) women. Tissue diagnosis was benign in 14 women and was not pursued in the remaining 5. Local recurrence occurred in 13 (3 %) patients, none of whom had calcifications on the new post radiation baseline mammogram. Conclusions: Mammographically apparent calcifications representing residual disease occur infrequently after BCS with negative margins. The value of PEM may be to document the new radiographic baseline but should not be required to ensure adequate surgery. Radiation plays an integral role in sterilization of the remaining breast tissue after BCS.