Received: 5 December 2020
Accepted: 5 April 2021
First Online: 6 May 2021
: This study was carried out according to the principles of the Declaration of Helsinki. The Ethics Committee of the Second Affiliated Hospital of Nanchang University waived informed consent because the data of this study using the SEER database were publicly available, de-identified, and retrospective.
: Not applicable.
: The authors declared that there was no conflict of interests.