R A Huddart1, R Jones2, A Choudhury3. 1. Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey SM2 5NG, UK. Electronic address: robert.huddart@icr.ac.uk. 2. Beatson West of Scotland Cancer Centre, Glasgow G12 0YN, UK. 3. The Christie NHS Foundation Trust, Manchester M20 4BX, UK.