1543 Response to Neoadjuvant Chemotherapy as An Indication for Breast-Conserving Surgery

Abstract Aim Pathological response to neoadjuvant chemotherapy (NAC) seeks induce tumour regression pre-operatively. The present study aimed assess NAC and evaluate the appropriateness of subsequent breast-conserving surgery (BCS) avoid disfiguration healthy breast tissue. Method Analysis all patients undergoing wide local excision (WLE) for primary cancer between April 2012 December 2020 at a tertiary unit was conducted. Statistical analysis performed using IBM® SPSS Statistics Software v27.0. Results A database 1490 female WLE retrieved, whom 88 received NAC. Average patient age 56 (SD = 11). Tumours were either invasive ductal (n 86, 97.7%) or lobular 2, 2.27%) carcinomas grade 2 31, 35.2%) 3 57, 64.8%). Chemotherapy regimens included: 30 FEC-T (34.1%), 22 FEC (25%), 19 TC (21.6%) 17 other (19.3%). On average, diameter (mm) decreased by 45.9%(34.5) with further 2.29%(57.7) from cessation excision. Tumour varied significantly across time points χ2 (3) 29.057, p < 0.001. Post-hoc tests revealed significant reduction in pre- post-NAC [Mean(SD): 29.6(10.9) vs 16.1(11.3), 0.001] pre-NAC [14.1(12.0), but not (p 1.000). Conclusions reduced addition There no statistical difference post-operative diameter, suggesting growth surgery. Our findings support use NAC, where possible, need large resection margins.