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Updated: Feb 15, 2026

Single-Port Robotic-assisted Transaxillary Breast-conserving Surgery: A Prospective, Single-arm, Non-randomized Phase IIa Clinical Trial
Published on: August 19, 2025
Routine shave margins are not necessary in early stage breast cancer treated with Breast Conserving Surgery
Carla Pajak1, JinSi Pao2, Amandeep Ghuman1
1University of British Columbia, Faculty of Medicine, Division of General Surgery, 950 West 10th. Avenue, Vancouver, BC V5Z 1M9, Canada.
Introduction:
Breast Conserving Surgery (BCS) is considered standard of care for women with early stage breast cancer. Between 20 and 50% of women treated with BCS will require re-operation for positive or close margins and it has been suggested that routine cavity shave margins may reduce the frequency of positive margins.
Methods:
Retrospective chart review of a prospectively maintained surgical database of patients undergoing BCS for early stage breast cancer, at a single institution, between January 2012 and December 2015. Cohort was followed until June 2016 to capture re-operations.
Results:
Among 2096 patients with stage 0-III breast cancers, 872 (42%) underwent primary mastectomies and 1224 (58%) underwent primary BCS. Margins were positive in 128 (11%) and close in 442 (36%). Re-operation rate for patients after BCS was 19%.
Conclusion:
A lower than predicted positive margin rate suggests that routine shave margins are not warranted at our institution.
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