Funding for this research was provided by:
Natural Science Foundation of Zhejiang Province of China (LY18H030008)
Wenzhou science and technology planning project (Y20180085)
Wenzhou Municipal Science and Technology Commission Major Projects Funds (Y20150029)
Received: 4 June 2019
Accepted: 20 September 2019
First Online: 10 October 2019
Ethics approval and consent to participate
: As the data used were from SEER dataset (public), ethics approval and consent to participate could be checked in SEER.
: Not Applicable.
: The authors declare that they have no competing interests.