Funding for this research was provided by:
Peking University Cancer Hospital (08-30)
Received: 20 November 2016
Accepted: 21 December 2017
First Online: 22 January 2018
Ethics approval and consent to participate
: Written informed consent was obtained from all patients and the study was approved by the Ethics Committee of Peking University Cancer Hospital.
: Not applicable.
: The authors declare that they have no competing interests.
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