Funding for this research was provided by:
the National Key R&D Program of China (2016YFC0902003)
Received: 29 April 2019
Accepted: 29 August 2019
First Online: 11 September 2019
Ethics approval and consent to participate
: This retrospective study was approved by the Clinical Research Committee of Sun Yat-sen University Cancer Center. Patients were required to provide written informed consent before enrolling in the study.
: Not applicable.
: The authors declare that they have no competing interests.