Funding for this research was provided by:
Fudan University Shanghai Cancer Center (YJ201603)
Young Scientists Fund (81702558)
Received: 18 December 2018
Accepted: 6 March 2019
First Online: 13 March 2019
Ethics approval and consent to participate
: The study was approved by the Fudan University Shanghai Cancer Center review board and the requirement for written informed consent was waived due to its retrospective design.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.