Text and Data Mining valid from 2020-03-20
Received: 20 October 2019
Accepted: 17 March 2020
First Online: 20 March 2020
Ethics approval and consent to participate
: The ethical committee of Fudan University Shanghai Cancer Center approved this study. Because of the retrospective nature of the study, the requirement for informed consent was waived.
: Not applicable
: The authors declare that they have no competing interests