Funding for this research was provided by:
Cancer Research UK (C1418/A14134, C7492/A17219)
Received: 25 April 2017
Accepted: 7 December 2017
First Online: 24 January 2018
Ethics approval and consent to participate
: Ethics approval for this study was obtained from the UCL Research Ethics Committee (registration number 5771/002) and all participants gave verbal consent to participate at the start of the survey.
: Not applicable
: The authors declare that they have no competing interests.
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