Funding for this research was provided by:
National Cancer Center (NCC-1610200)
Yonsei University College of Medicine (2017-32-0033)
Received: 27 September 2017
Accepted: 9 May 2018
First Online: 29 May 2018
Ethics approval and consent to participate
: Ethical approval for the research protocol was provided by the institutional review board of the National Cancer Center (NCC2017–0168) which waived the requirement for informed consent. The authorization for data processing was obtained from the National ‘Cancer Control Act’.
: The authors declare that they have no competing interests.
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