Funding for this research was provided by:
World Cancer Research Fund (2011/RFA/473)
Text and Data Mining valid from 2019-11-06
Received: 25 September 2019
Accepted: 26 October 2019
First Online: 6 November 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This study was approved by the ethical committee of the Jiangsu Center for Disease Control and Prevention (Jiangsu, China).
: All participants signed a written informed consent.