Abstract ES6-1: Less is more: minimising surgery
Authors: MacNeill F 
Published: May 2016

Abstract
Introduction
Surgery is a highly targeted individualised treatment which has an important role in the successful multi-modality management of breast cancer (BC). However similar to all cancer treatments it has substantial physical and psychological morbidity and has to be used appropriately to maximise benefit and minimise harm. It is noteworthy BC mortality continues to decline 'despite' more conservative surgery but crucially this is in parallel with earlier diagnosis and better use of a wide range of systemic therapies. Multidiscipline working is vital to the success of multi-modality treatment planning.
Primary systemic therapy facilitates less radical breast and axillary surgery
The primary role of surgery is historical and based on tradition, but as we better understand the biology and heterogeneity of BC and the utility of systemic therapies we have altered treatment sequences and achieved similar or even better survival and disease free outcomes. Whilst surgery remains a core treatment to achieve cure and maintain effective local disease control, shifting surgery from the primary to an adjuvant setting can reduce the need for mastectomy and axillary clearance. The increasing use of biologically targeted primary medical therapies to downstage and down size disease and so facilitate more conservative surgery in the breast and (perhaps more controversially) in the axilla has an exciting future and may even challenge the need for any surgery in selected individuals. However we currently lack good evidence with regards to who will still benefit from mastectomy and axillary clearance and who can safely be offered more conservative 'risk-adapted' surgery or even no surgery at all.
Margins guidelines, intraoperative margin assessment and oncoplastic surgery can extend the role of breast conservation and reduce re-excision rates
Re-excision rates (up to 30% for DCIS) are the 'elephant in the room' for breast conserving surgery: a concerted effort is required to bring these in line with the best (5%). Recent guidelines defining narrower acceptable margins for breast conservation, intra-operative margin assessment and the use of oncoplastic surgery techniques (which allow resection of larger tumours and wider excisions but maintain the aesthetic outcome) can have a major impact on reducing re-excision rates.
'Risk-reducing' bilateral mastectomy for unilateral cancer: an urgent problem to be addressed
It is ironic that as surgery has the potential to become less onerous, bilateral mastectomy rates are rising dramatically. If this is as part of a structured risk reduction strategy for high risk individuals then it must be supported until we have less radical solutions. But if it is our only response to fear and poor understanding of risk in women with unilateral BC then we need to urgently re-evaluate how we can manage the situation. Whilst the availability and quality of breast reconstruction has improved it is not a risk free or easy alternative.
Over diagnosis and over treatment
Advances in medical technology can drive overdiagnosis of BC which in turns drives potentially unnecessary, radical and harmful surgery in uncertain surgeons and fearful women. In particular breast MRI has to be used with caution: it does not reduce re-excision rates and may drive mastectomy with no survival advantages.
Citation Format: MacNeill F. Less is more: minimising surgery. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES6-1.