AB230. SOH26AB_0398. Factors influencing re-excision following wide local excision: a single symptomatic breast unit’s experience

Background: Modern breast cancer management often involves breast-conserving surgery, aiming to achieve oncologic safety while maintaining an aesthetic outcome. The major risk with breast-conserving surgery is leaving a positive margin, thus needing further surgery. With the recent adoption of MagSeed over wires as the standard localisation technique, we aimed to assess the impact on re-excision rates.

Methods: A single institution retrospective cohort study of all patients who underwent a wide local excision (WLE) for breast cancer [2020–2024] at University Hospital Limerick was conducted. The period was centred around the transition from wire-guided WLEs to MagSeed-guided WLEs. We recorded localisation method (if used), histopathology, stage at time of operation, receptor status, and use of neo-adjuvant chemotherapy.

Results: Over the course of 5 years, 485 WLEs were performed, with 113 (23.3%) requiring either re-excision or completion mastectomy. Regarding localisation modalities, 52/199 (26.1%) wire-guided WLEs required re-excision, compared to 38/182 (20.9%) MagSeed-guided WLEs, and 23/104 (22.1%) WLEs performed without a localiser.

Conclusions: The introduction of the Magseed guided excision has demonstrated a noticeable improvement in re-excision rates compared to the traditional wire-guided localization technique. Our re-excision rate is slightly higher than previously published rates for Ireland and the United Kingdom (17%).

Keywords: Breast cancer; breast-conserving surgery; localisation modality; re-excision; re-operation