Funding for this research was provided by:
Deutsche Krebshilfe (110948)
Received: 26 September 2018
Accepted: 2 August 2019
First Online: 22 August 2019
Ethics approval and consent to participate
: The study received research ethics committee approval in January 2014 from the responsible institutional ethics board of the medical faculty of the University of Leipzig (Reference number 372–13-16122013). Before the participants were provided with the link for answering the standardized study questionnaire online, or if o desired, a hard copy of the questionnaire sent by post, written consent to participate voluntarily in the study had to be on hand (patient master sheet and consent form).
: Not applicable.
: The authors declare that they have no competing interests.