Received: 25 June 2020
Accepted: 22 October 2020
First Online: 11 November 2020
Ethics approval and consent to participate
: This retrospective study was approved by the Institutional Review Board (IRB) of the National Cancer Center Hospital (IRB code: 2015–320). It was determined to be a retrospective analysis of de-identified data, and was determined to be exempt from requiring written informed consent. IRB of the National Cancer Center Hospital approved to access the clinical/personal patient data used in our research.
: Not applicable.
: The authors declare that they have no competing interests.