Funding for this research was provided by:
National Natural Science Foundation of China (81872204)
Received: 14 April 2021
Accepted: 19 June 2021
First Online: 2 July 2021
: The study was conducted in accordance with the principles of the Declaration of Helsinki, and the study protocol was approved by the ethics committee of the Affiliated Cancer Hospital of Zhengzhou University. Because of the retrospective nature of the study, the requirement for patient consent was waived.
: Not applicable.
: The authors declare that they have no competing interests.