Intra-operative re-excision of margins in breast-conserving surgery: How well are we able to judge tumour proximity?

s / International Journal of Surgery 10 (2012) S1–S52 S15 ABSTRACTS 1127: INTRA-OPERATIVE RE-EXCISION OF MARGINS IN BREASTCONSERVING SURGERY: HOW WELL ARE WE ABLE TO JUDGE TUMOUR PROXIMITY? Lorna Cook, Debasish Debnath, Zoe Lin, Raouf Daoud, Isabella Karat, Ian Laidlaw. Frimley Park Hospital, Frimley, UK Introduction: In breast-conserving surgery (BCS), specimen margin involvement with tumour often necessitates re-operation. For this reason, extra margins are often taken at the time of primary operation. The aim of this study was to determine how often such re-excisions are appropriate. Methods: The records of 100 consecutive patients undergoing BCS for cancer during 2011 were analysed. Data was collected on demographics, tumours characteristics, surgery performed and final histology. Results: All 100 patients were female, median age 56 years (range 33-83 years). 66% had intra-operative re-excision of margins. In 26/66 (40%), re-excision was the correct decision. 25 of the 34 patients who had no extramargins taken at all were managed appropriately with the remaining 9 patients having close/positive margins. Unnecessary re-excisions were performed in 40/66 patients. The correct intraoperative decision was therefore made in 51% of patients. Conclusion: The decision regarding intra-operative margin re-excision was appropriate in just over half of all cases and a second operation was avoided in 26%. However, in order to preserve as much uninvolved breast tissue as possible, further work should be done on methods to improve accuracy and to determine whether there are any patient, radiological or pathological predictors to guide intra-operative re-excision. 1181: FACTORS PREDICTING POSITIVE MARGIN STATUS IN BREAST CANCER PATIENTS UNDERGOING BREAST CONSERVING SURGERY Euan Harris , Andrew Lee . University of Dundee, Dundee, Tayside, UK; Abertawe Bro Morgannwg University Healthboard, Swansea, West