Sample selection~- Select communities of 20,000 to 40,000 populations in Zhongshan City and Wuzhou city as the investigators' fields.~Participants recruitment~Subjects voluntarily attend this screening study Informed consent - Informed consent forms will be collected at the recruitment. Questionnaires.~Face-to-face interviews are conducted by well-trained investigators.~Tests and follow up~At initial screening, all participants will be tested for EBV associated biomarkers, including EBNA1-IgA, VCA-IgA, P85-Ab et al. And in males, EBV-DNA will be tested. Based on EBNA1-IgA, VCA-IgA, participants will be stratified into high, moderate and low risk. Screening positive include P85-Ab positive, high or moderate risk of NPC or EBV DNA positive. The rest will be screening negative.~During the initial screening and following up, people with high risk or P85-Ab positive will refer to the diagnostic workup for NPC. Briefly, fiberoptic endoscopy and pathological biopsy will be performed by otorhinolaryngologists.~Screening positive people not diagnosed as nasopharyngeal carcinoma in the first year will be followed up annually.~EBV DNA single positive people will refer to the diagnostic workup for NPC in the third year of follow up.~The rest of the blood samples will be stored at the biobank of Zhongshan People's Hospital for further research.~All subjects will also be followed by record linkage to Cancer Register and Population Register.
All participants will be tested for EBV associated biomarkers, including EBNA1-IgA, VCA-IgA, BNLF2b total antibodies (P85-Ab) et al. For all male participants and P85-Ab positive female participants, EBV DNA in plasma will be tested. Screening positive participants will be followed up annually.~All subjects will also be followed by record linkage to Cancer Register and Population Register.