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

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.