AB231. SOH26AB_0427. Margin positivity in breast-conserving surgery after neoadjuvant therapy: a systematic review and meta-analysis
General Posters II

AB231. SOH26AB_0427. Margin positivity in breast-conserving surgery after neoadjuvant therapy: a systematic review and meta-analysis

Niamh Keating, Tim Harding, Jane Rothwell, Denis Evoy, Damian McCartan, Ruth Prichard, Michael Boland

Department of Surgery, St. Vincent’s University Hospital, Dublin, Ireland

Background: The role of neoadjuvant systemic therapy (NAST) in the management of breast cancer has expanded dramatically over recent decades. By reducing tumour burden, NAST promotes the feasibility of breast-conserving surgery (BCS) and has the potential to reduce the morbidity of extensive axillary surgery. Across published studies, reported rates of margin positivity after BCS in the post-NAST setting vary, reflecting discrepancies in margin definitions, pathological assessment, and patterns of treatment response. This variability underscores the need for a robust synthesis of the available evidence. This systematic review and meta-analysis aimed to quantify margin positivity rates after NAST and additionally to identify factors associated with positive margins.

Methods: A systematic search of PubMed, Embase, and Scopus databases was performed. Eligible studies included adult patients with invasive breast cancer treated with NAST followed by BCS and reporting resection margin status. Extracted variables included tumour characteristics, shrinkage pattern, re-excision rates, completion mastectomy rates, and local recurrence-free survival. Risk of bias was assessed using the Newcastle-Ottawa scale. Pooled estimates were calculated using random-effects models.

Results: Six studies met the inclusion criteria, representing 1,353 patients. The pooled margin positivity rate was 32.3% [95% confidence interval (CI): 25.5–39.0%]. Five studies reported re-excision rates for positive margins, which ranged from 8.1% to 32.7%.

Conclusions: Margin positivity after BCS in the post-NAST setting is common and varies widely across the published literature. The heterogeneity of results highlights the need for large-scale standardised approaches to reporting and assessment, to more accurately define oncological outcomes and guide best-practice for breast conservation after NAST.

Keywords: Breast-conserving surgery (BCS); margin positivity; meta-analysis; neoadjuvant systemic therapy (NAST); surgical margins

Acknowledgments

None.

Footnote

Funding: None.

Conflicts of Interest: The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

doi: 10.21037/map-26-ab231
Cite this abstract as: Keating N, Harding T, Rothwell J, Evoy D, McCartan D, Prichard R, Boland M. AB231. SOH26AB_0427. Margin positivity in breast-conserving surgery after neoadjuvant therapy: a systematic review and meta-analysis. Mesentery Peritoneum 2026;10:AB231.

Article Options

Download Citation

Share