Multicentre prospective observational study evaluating recommendations for mastectomy by multidisciplinary teams
Authors:   Mastectomy Decisions Audit (MasDA) Collaborative, Singh Jagdeep K , McEvoy Katherina , Marla Sekhar , Rea Daniel , Hallissey Michael , Francis Adele , Fatayer Hiba , Murphy Claire , Pang Calver , Gomez Kelvin , Lefemine Valentina , Zaharan Muhammad , Gateley Christopher , Holland Philip , Mohamud Mohamed , Dicks Julia , Khan Shazia Mansoor , Day Nicola , Sandi Anita , Ullah Md Zaker , Venn Mary , Chicken Dennis Wayne , Saad Abdalla , Salih Ali , McGoldrick Ciara , Volleamere Angela J , Wright Chloe , Rathinaezhil Rathi , Ugolini Fiammetta , Agrawal Amit , Arima Yuriko , Benson John , Forouhi Parto , Apte Anuradha , Chakravorty Arunmoy , Chandrasekharan Sankaran , Marsh Simon , Pennell Lesley , Harding-Mackean Claudia , Redmond Elizabeth , Seward Joanna , Laine Sarah , Pooley Gemma , Ramzi Saed , Athanasiou Irene , Olubowale Olumuyiwa , Rogers Clare , Wilkinson Nicola , Crane Peter , Deol Harleen , Patani Neill , Walsh Una , Wood Jeremy , Keay Jonathan , Roshanlall Chandeena , Pronisceva Veronika , Sharp Elizabeth , Clayton Elizabeth , Ford Jordan , Kanesalingam Kavita , Karat Isabella , Kemeny Catriona , Khan Asad , Shah Nikki , Clark Kevin , Fasih Tani , Makam Kishore , Nangalia Ramlal , Sein Tin , Al-Allak Asmaa , Bristol James , Court Fiona , Fowler Clare , Hunt Richard , Kallaway Charlotte , Llewellyn-Bennett Rebecca , Massey Eleanore , Orchard Philippa , Vestey Sarah , Dragoumis Dimitrios , Laws Siobhan , Almerie Muhammad Qutayba , Ray Biswajit , Hameed Alia , Haq Anwar , Adi Rudwan , Mirza Shaukat , Gullaksen Elaine , McManus Penelope , Mortimer Caroline , Venn Mary , Downey Sarah , Joglekar Sandeep , Chin Kian , Kuzhively Raju , Safdar Gazalla , Taylor Amanda , Chopra Sharat , Johnson Richard , Krishnan Vummiti Murali , Arthur Laura , Musyoka Caroluce , Abbott Nick , Pollard Jennifer , Fitzgerald Kate , Lannigan Alison , McCrone Debbie , McGarry Keith , McGivern Jayne , McKenzie Clare , Murphy Dermot , Murray Juliette , Al-Hattali Samiya , Macaskill E Jane , Ainsworth Rachel , Dash Isabella , Ahmad Tanvir , Groome John , Moon Charlotte , Rajaretnam Niroshini , Heaney Elaine , McFall Brendan , Amonkar Sunil , Aspinall Sebastian , Carr Michael , Edwards Karen , Elliott Helen , Mann Lynn , Spence Laura , Walshe Amanda , Yousef Magdi , Akerlund Malin , Bignell Kym , Brock Lisa , Kelsall Jennett , Otieno Charlene , Whisker Lisa , Battersby Nick , Evans Abigail , Harvey Kate , Agrawal Avi , Zaidi Masooma , Al-Gailani Mohamed , Kumar Inder , MacInnes Emma , Ferguson Douglas , Green Sara , Youssef Mina , Ali Oroog , Hoar Fiona , McEvoy Katherina , Rea Ian , Jafferbhoy Sadaf , Lake Blossom , Sheikh Hammad , Donnelly Peter , Green Michael , Ives Charlotte , Minto Samantha , Irwin Gareth , Kirk Stephen , Clarke Dayalan , Enser Debbie , Harries Simon , Jones Lucie , Tafazal Habib , Chagla Leena , Hodigere Ramesh , Kiernan Tamara , Chana Manik , Thorne Amanda , Walker Thomas , Croydon Hilary , Singh Jagdeep K , Archampong David , Johnson Laura , Di Micco Rosa , O'Connell Rachel L , Richardson Caroline , Rusby Jennifer E , Soldanova Ludka , Isgar Brian , Matey Pilar , Mylvaganam Senthurun , Raouf Zaid , Salem Fathi , Sircar Tapan , Vidya Raghavan , Gvaramadze Anzors , Sami Amtul , Thekkinkattil Dinesh Kumar , Turner Nicky , Lechi Tracey , Robertson Stuart , Waili Ibrahim Al , Francis Adele , Magill Laura , Marla Sekhar , Perry Rita , Wilcox Margaret , Ayaani Soofiyah , Dean Samera , Mahmood Mohammed , Tomlins Abigail , Appleton Donna , Kaushik Monika , Khout Hazem , Mondani Giuseppina , Pilgrim Simon , Rattay Tim , Gilani Shahid , Narayanan Sankaran , Soumian Soni , Tandon Megha , Brookes Phil , Ferguson Henry , Gaughan Jenni , Heitmann Marlies , Iqbal Mohd , Aitken Jane , Odofin Olubunmi , Wosu Chukwuemeka , Betal Dibendu , Bonomi Riccardo , Ainsworth Rachel , Dash Isabella , Rossi Chiara , James Karen , Vinayagam Raman , Baker Elizabeth , Chandra Amrita , Kim Baek , Munot Kailas , Nasr Rana , Piper Jenny 
Published: November 2019

Abstract

Background
Recommendations for mastectomy by multidisciplinary teams (MDTs) may contribute to variation in mastectomy rates. The primary aim of this multicentre prospective observational study was to describe current practice in MDT decision-making for recommending mastectomy. A secondary aim was to determine factors contributing to variation in mastectomy rates.

Methods
Consecutive patients undergoing mastectomy between 1 June 2015 and 29 February 2016 at participating units across the UK were recruited. Details of neoadjuvant systemic treatment (NST), operative and oncological data, and rationale for recommending mastectomy by MDTs were collected.

Results
Overall, 1776 women with breast cancer underwent 1823 mastectomies at 68 units. Mastectomy was advised by MDTs for 1402 (76·9 per cent) of these lesions. The most common reasons for advising mastectomy were large tumour to breast size ratio (530 women, 29·1 per cent) and multicentric disease (372, 20·4 per cent). In total, 202 postmenopausal women with oestrogen receptor-positive (ER+) unifocal tumours were advised mastectomy and not offered NST, owing to large tumour to breast size ratio in 173 women (85·6 per cent). Seventy-five women aged less than 70 years with human epidermal growth factor receptor 2-positive (HER2+) tumours were advised mastectomy and not offered NST, owing to large tumour to breast size ratio in 45 women (60 per cent).

Conclusion
Most mastectomies are advised for large tumour to breast size ratio, but there is an inconsistency in the use of NST to downsize tumours in patients with large ER+ or HER2+ cancers. The application of standardized recommendations for NST could reduce the number of mastectomies advised by MDTs.