Funding for this research was provided by:
Langfang Science and Technology Support Project of Hebei Province (2020013089)
Received: 17 January 2021
Accepted: 18 March 2021
First Online: 6 April 2021
: The designed protocol (2020013089 dated 22 July 2020) was approved by the Hebei Petrochina Central Hospital's review board and the Society of Chinese surgeons. The study reporting adheres to the law of China and the v2008 Declarations of Helsinki. An informed consent form was signed by relatives (legally authorized person) of patients regarding diagnosis, surgery, pathology (if any), chemotherapy, and publication of the anonymized information of patients in the form of the article during hospitalization. As the study was a retrospective analysis, the registration in the Chinese Clinical Trial Registry was waived by the institutional review board.
: The authors declare that they have no competing interests.