Received: 22 July 2020
Accepted: 11 December 2020
First Online: 5 January 2021
Ethics approval and consent to participate
: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study disclosed information using an opt-out method and excluded patients who did not consent to the study. This study was reviewed and approved by the Institutional Review Board of Catholic Medical Center [KC18SESI0440], based on the provisions of the Helsinki Declaration, as revised in 2013 (available at: ExternalRef removed). The written informed consent was obtained from every single patient.
: Not applicable.
: JH Kang has acted as an advisor for Merck, MSD, Ono/BMS, AstraZeneca, Eli Lilly, and Yuhan, has received research funding from Ono, AstraZeneca, Boehringer Ingelheim, Yuhan, and Daichi Sankyo, and has acted as a speaker for Pfizer, Roche, Merck, and Boehringer Ingelheim. All the other authors declare no conflicts of interest.