Document is current
Any future updates will be listed below
-
Authors
- License Information
-
More Information
Article History
Received: 27 May 2020
Accepted: 26 December 2020
First Online: 4 February 2021
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: Written informed consents were exempt since the data we used were obtained from the publicly available SEER database.
: All procedures performed in these studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study was deemed exempt by the Ethics Committee of Peking Union Medical College Hospital, Beijing, China, since the data we used were obtained from the publicly available SEER database.
