Cavity Shave Margins in Breast Conservative Surgery a Strategy to Reduce Positive Margins and Surgical Time

Abstract

Background: Resection of additional tissue circumferentially around the cavity left by lumpectomy (cavity shave) was suggested to reduce rates of positive margins and re-excision. Methods: A single center retrospective study which analyzed margins status, re-excision, and surgical time in patients who underwent breast conserving surgery and cavity shave or intraoperative evaluation of resection margins. Results: Between 2021 and 2023, 594 patients were enrolled in the study. In patients subjected to cavity shave, a significant reduction in positive, focally positive, or closer margins was reported 8.9% vs. 18.5% (p = 0.003). No difference was reported in terms of surgical re-excision (p < 0.846) (5% vs. 5.5%). Surgical time was lower in patients subjected to cavity shave (<0.001). The multivariate analysis intraoperative evaluation of sentinel lymph node OR 1.816 and cavity shave OR 2.909 were predictive factors for a shorter surgical time. Excluding patients subjected to intraoperative evaluation of sentinel lymph node and patients with ductal carcinoma in situ, patients that underwent the cavity shave presented a reduced surgical time (67.9 + 3.8 min vs. 81.6 + 2.8 min) (p = 0.006). Conclusions: Cavity shaving after lumpectomy reduced the rate of positive margins and it was associated with a significant reduction in surgical time compared to intraoperative evaluation of resection margins.

Impact of cavity shave margins in patients with ductal carcinoma in situ undergoing conserving breast surgery

“…We believe that routine cavity shaving could help the physician obtain a negative margin. Our previous retrospective analysis, comparing cavity shaving and intraoperative evaluation of resection margin by the pathologist in invasive cancer, highlighted a significant reduction of positive margins; however, there was no statistically significant difference in margins after re-excision ( 16 ). This dissimilarity between in situ lesions and invasive breast cancer could be justified by the different growth patterns between the lesions ( 16 ).…”

“…Our previous retrospective analysis, comparing cavity shaving and intraoperative evaluation of resection margin by the pathologist in invasive cancer, highlighted a significant reduction of positive margins; however, there was no statistically significant difference in margins after re-excision ( 16 ). This dissimilarity between in situ lesions and invasive breast cancer could be justified by the different growth patterns between the lesions ( 16 ). Furthermore, the absence of tactile feedback from the nodule in DCIS lesions can make it more difficult to obtain a disease-free surgical margin, and especially in these patients, the cavity shaving technique could reduce the risk of positive margins and the need for surgical re-excision.…”