1 Jesus College, University of Cambridge, Jesus Lane, CB5 8BL, UK. Electronic address: za272@cam.ac.uk.
2 Trinity Hall, University of Cambridge, CB2 1TJ, UK.
3 Department of Plastic and Reconstructive Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK.
4 Department of Plastic and Reconstructive Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK; Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK; Anglia Ruskin University School of Medicine, Chelmsford, Cambridge, UK.