Pan, Yafeng
Hong, Yuming
Liang, Zhenyuan
Zhuang, Wei
Article History
Received: 1 October 2018
Accepted: 8 December 2018
First Online: 12 December 2018
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: All procedures performed in studies involving human participants conform to the standards of the institutional and national ethics committees, as well as to the 1964 Helsinki Declaration and subsequent relevant ethics. Patient informed consent is not required to extract data from the SEER database.
: All authors are informed and consent for publication.
: All data were acquired from the SEER database. We obtained the authorization to access the SEER database with the number 14260-Nov2016.