Low re-excision rate for positive margins in patients treated with ultrasound-guided breast-conserving surgery

Background: Re-excision is a necessary procedure in obtaining clean margins for breast-conserving surgery (BCS)-treated patients. Re-excision rates vary widely among different breast cancer management procedures. The aim of this study was to evaluate the efficacy of ultrasound (US)-guided BCS to decrease the re-excision rate in patients with US-detectable breast cancer, as well as the relationship between positive margins and ultrasonographic characteristics of tumor. Methods: Between 2008 and 2009, we identified consecutive patients who underwent initial US-guided BCS for breast in situ or invasive carcinoma, which was preoperatively detected using US examination and on the basis of image-guided biopsy findings. The margins achieved after BCS were separately assessed by performing frozen section analysis of shaved margins. The negative margin and positive margin groups were compared for clinicopathological features and ultrasonographic findings. Results: Of 381 patients undergoing US-guided BCS, 126 (33.1%) had palpable tumors and 255 (66.9%) had nonpalpable tumors. Positive margins were noted in 35 patients (9.2%). These patients underwent re-excision and were margin-free; no further surgery was required for these patients. There were no significant intergroup differences in clinicopathological features and ultrasonographic findings. Conclusion: Breast US is an effective modality for intraoperative tumor localization and can thus help obtain clean margins and reduce the re-excision rate in cases in which breast-conserving therapy has been performed. Furthermore, frozen section analysis of cavity shaved margins is a feasible method for minimizing the need for further surgery.