Received: 18 November 2020
Accepted: 23 March 2021
First Online: 13 April 2021
: The study was approved by the local ethics committee of Osaka International Cancer Institute (Approval number: 1707105108) and was conducted in accordance with the Declaration of Helsinki. The requirement for informed consent was waived due to the retrospective nature of the study.
: Not applicable.
: There are no conflict of interest to declare.