Wang, Gang
Li, Qiken
Chen, Weiping
Article History
Received: 30 March 2021
Accepted: 9 June 2021
First Online: 6 July 2021
Declarations
:
: Not applicable. As the SEER dataset is publicly available and de-identified, therefore, the ethical approval was waived by the ethics committee of our hospital.
: Not applicable.
: The author(s) declare no competing interests.