EP.TH.930Contemporary trends in the management of micrometastatic axillary disease in the setting of mastectomy – a 5 year single institution experience

Abstract Background Since the ACOSOG Z0011 trial, rates of axillary node clearance (ANC) for micrometastatic disease have declined among women undergoing breast conservation surgery (BCS). However, mastectomy, it remains unclear whether omission ANC is a safe and feasible option. Aims Identify current practice relating to management axilla in with early stage, clinically negative cancer, found on SNB, who undergo mastectomy Methods From 2013 2017 patients clinical T1-T2Nmi cancer upfront were identified from prospective institutional database. Receipt adjuvant radiotherapy or subsequent assessed. Patients received neoadjuvant chemotherapy BCS excluded. Results 47 ESBC had micrometastasis SNB. The majority tumours invasive ductal histology. 16/27 underwent completion (34%). Six further nodal specimen. 2 >5 nodes positive. During study period 31 (65%) radiotherapy. Of did not ANC, 21 (67.7%) Conclusion At this institution requiring SNB do (>60%). Although small patient cohort, these data indicate rate residual low, are keeping trends literature, may help inform decisions group.