Text and Data Mining valid from 2020-01-03
Received: 18 September 2019
Accepted: 23 December 2019
First Online: 3 January 2020
Ethics approval and consent to participate
: This study design and exemption of informed consents were approved by the Institutional Review Board of the Korea Cancer Center Hospital (IRB no. KIRAMS 2019-03-009).
: Not applicable.
: The authors declare that they have no competing interests.