Text and Data Mining valid from 2019-05-17
Received: 17 November 2018
Accepted: 8 May 2019
First Online: 17 May 2019
Ethics approval and consent to participate
: The Clinical Research Ethics Committee of Sun Yat-sen University Cancer Center approved the research and the written informed consent was waived because this was a retrospective and observational study.
: Not applicable.
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