Text and Data Mining valid from 2020-02-04
Received: 3 July 2019
Accepted: 24 January 2020
First Online: 4 February 2020
Ethics approval and consent to participate
: We declare that this study has obtained the report of ethics board approval and informed consent obtained from each participate has been written before surgery. The study was approved by the ethics committee of Peking University Cancer Hospital & Institute, Beijing, China on Dec. 2017. The protocol number is 2017KT107.
: Not applicable.
: The authors declare that they have no competing interests.