High resolution intra-operative two-dimensional specimen mammography and its impact on second operation for re-excision of positive margins at final pathology after breast conservation surgery.

BACKGROUND: In the United States, about 50% to 66% of women undergoing breast conservation surgery for cancer undergo subsequent mastectomy for positive margins on initial lumpectomy. This is despite the fact that screening mammography has resulted in a decrease in the size of newly diagnosed breast cancer to <2 cm.
METHODS: A retrospective review of 128 patients who underwent breast conservation surgery for early breast cancer was performed using intraoperative 2-dimensional Faxitron high-resolution specimen mammography without specimen compression as the only margin assessment technique. Of these, 29 patients had histories of lumpectomy with positive margins.
RESULTS: A total of 131 procedures were performed. Margins were histologically clear at initial breast conservation surgery in 84.3% of patients who underwent primary lumpectomy. Subsequent reexcision for positive margins was required in 14.7% of patients. Two-dimensional Faxitron mammographically guided intraoperative reexcision cleared the margins in 95.8% of patients (23 of 24) who would have otherwise required subsequent reexcision.
CONCLUSIONS: Intraoperative 2-dimensional Faxitron high-resolution specimen mammography can decrease rates of margin positivity and has the potential to diminish the number of subsequent undesired mastectomies for positive margins.