Received: 28 September 2018
Accepted: 17 December 2018
First Online: 3 January 2019
: Authors declare that they have no competing interest.
: Ethical approval was given by the institutional review board of Osaka International Cancer Institute on 30 March 2018 (approved clinical study number: 1803309441). Individual consent was waived because this study was retrospective in design and based on database extracted records.
: Not applicable.
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