Received: 25 November 2020
Accepted: 3 February 2021
First Online: 12 February 2021
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board (IRB) of PUMCH (IRB number: S-K1227). All clinicopathologic data extracted in this study were obtained from our database.
: Not applicable.
: The authors declare that they have no competing interests.