Intraoperative margin assessment and re-excision rate in breast conserving surgery

Aim: The aim of this study was to assess the efficacy of intraoperative margin assessment in obtaining clear margins in conserving surgery for breast cancer. Methods: Two hundred and twenty patients undergoing wide local excision (WLE) for core biopsy proven primary invasive breast cancer, during a 30 months period, were included in the study. Following surgical excision the breast specimen was orientated with sutures, inked using India ink and coloured pigments and incised to identify the tumour, maintaining orientation. The distance to the individual radial margins were estimated macroscopically by the pathologist and conveyed intraoperatively to the surgeon. A macroscopic tumour-margin distance of less than 10 mm was considered compromised and the margin(s) in question was then excised if feasible. Results: Eighty-one patients (37%) were judged to have compromised margins following intraoperative macroscopic evaluation and had at least one margin re-excised. Sixteen of the 81 patients (20%) in this subgroup had compromised margins on microscopy and required a second operation. One hundred and thirty-nine patients (63%) were deemed to have clear margins intraoperatively, subsequently confirmed on microscopic examination in 135 patients (97%). Intraoperative macroscopic assessment of margin status was associated with 9.1% of patients requiring a second operation. In the absence of intraoperative assessment of margin status a further 47 patients (21.4%) would have required a second operation. Conclusion: Intraoperative macroscopic margin assessment is an effective technique in reducing the number of second operative procedures in patients undergoing conserving surgery for primary invasive breast cancer.