Does intra‐operative margin assessment improve margin status and re‐excision rates? A population‐based analysis of outcomes in breast‐conserving surgery for ductal carcinoma in situ. Issue 7 (7th October 2018)

• Record Type: Journal Article
• Authors: Laws, Alison; Brar, Mantaj S; Bouchard‐Fortier, Antoine; Leong, Brad; Quan, May Lynn
• Is Part Of: Journal of surgical oncology. Volume 118:Issue 7(2018)
• Page Start: 1205
• Page End: 1211
• Publication Date: 2018-10-07
• Subjects: intra‐operative ultrasound -- macroscopic margin assessment -- residual disease -- specimen mammography; Cancer -- Surgery -- Periodicals; Neoplasms -- Periodicals; 616
• DOI: 10.1002/jso.25248
• Languages: English
• ISSNs: 0022-4790

Abstract

Abstract : Background and Objectives: Using a 2 mm margin criteria, we evaluated the effect of intra‐operative margin assessment on margin status and re‐excisions following breast‐conserving surgery (BCS) for ductal carcinoma in situ (DCIS). Methods: We identified patients undergoing BCS for DCIS from a prospective, population‐based database. Multivariable logistic regression was used to determine the effect of specimen mammography, ultrasound and macroscopic assessment by a pathologist on margins and re‐excision rates. Results: In 588 patients, 52% (95% confidence interval [CI], 48%‐56%) had positive margins (<2 mm), 39% (95% CI, 35%‐43%) had a re‐excision and 15% (95% CI, 12%‐18%) had completion mastectomy. There were few re‐excisions for margins ≥2 mm (2%). Adjusting for confounders, any margin assessment versus wire localization alone did not reduce positive margins (odds ratio [OR], 0.75; P = 0.202) or re‐excisions (OR, 1.14; P = 0.564), however both outcomes varied by type of technique ( P < 0.001). Individually, only macroscopic assessment by pathologist reduced positive margins (OR, 0.54; P = 0.002) and re‐excisions (OR, 0.61; P = 0.036). Conclusions: Despite adherence to a 2 mm margin criteria, re‐excision rates remain high following BCS for DCIS, with 39% converted to mastectomy when re‐excision is required. Intra‐operative margin assessment does not appear to reduce re‐excisions; in particular, surgeons should be aware of the limitations of specimen mammography for margin assessment in DCIS.