Funding for this research was provided by:
National Key Research and Development Program of China “precision medical research” (2016YFC0900502)
Zhejiang Medical and Health Technology Project (2021KY614)
Received: 3 September 2020
Accepted: 19 January 2021
First Online: 28 January 2021
Ethics approval and consent to participate
: This study was carried out in accord with the “Declaration of Helsinki” and the verbal consents were obtained from participants and approved by the Ethics Committee of Zhejiang Provincial Center for Disease Control and Prevention (CDC). The ethics committee approved the procedure for verbal consent because Zhejiang CDC has the authority of the Zhejiang provincial government to collect and publish the cancer related information, which is part of disease surveillance scope in Zhejiang CDC. All the participants (cases and controls) were notified that they have the right to refuse or terminate the study at any point of the interview. Because we obtained verbal consent, documentation of consent was not required. However, the information provided by each participant was kept confidential in Zhejiang CDC.
: Not applicable.
: The authors declare that they have no competing interests.