Received: 8 April 2021
Accepted: 18 August 2021
First Online: 1 September 2021
: The study was conducted in compliance with the provisions of the Declaration of Helsinki.The study protocol was approved by the Institutional Review Board of the National Cancer Center, Tokyo, Japan (approval number: 2001-013, 14-038). The present study protocol was approved by the Ethical Review Board of Osaka University, Osaka, Japan (approval number: 14020-9). All participants were informed of the objectives of the study and that completion of the survey questionnaire was regarded as providing informed consent.
: Not applicable.
: The authors declare that there are no competing interests.