Funding for this research was provided by:
Capital Health Research and Development of Special (2016-2-4022)
Beijing Hope Run Special Fund of Cancer Foundation of China (LC2017A19)
Received: 15 May 2019
Accepted: 29 August 2019
First Online: 14 September 2019
Ethics approval and consent to participate
: The ethics committee of the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College approved this study.
: The authors declare that they have no competing interests.