Objective:To observe the differences in the dynamic change of the EB virus antibody between general population and first-degree relatives (FDR) of nasopharyngeal carcinoma patients during follow-up study one year after initial screening and discuss the difference among the nasopharyngeal carcinoma detections. Methods: Serologic data of all subjects that participated in the fol-low-up study were collected. Changes in EB virus antibodies were investigated and correlation of these changes with gender and age level was analyzed. Differences in the nasopharyngeal cancer detection rate of different populations were also compared. Results:NA1/IgA negative conversion rate was higher in the family group than in the control group (χ2=20.28, P<0.001). This rate was also higher in both male and female family groups than in the male and female control groups (χ2=22.59, P<0.001;χ2=4.03, P<0.05, respectively). NA1/IgA positive conversion rate was lower in the family group than in the control group (χ2=7.79, P<0.05). Likewise, this rate was lower in both male and female family groups than in the male and female control groups (χ2=9.46, P<0.05;χ2=0.74, P=0.39, respective-ly). VCA/IgA negative conversion rate was higher in the family group than in the control group (χ2=1.90, P<0.001). This rate was also higher in the male and female family groups than in the male and female control groups (χ2=7.50, P<0.05; χ2=no expression, P=0.108, determined by Fish exact test, respectively). VCA/IgA positive conversion rate was higher in the family group than in the control group (χ2=0.10, P=0.70). This rate was again higher in both male and female family groups than in the male and female control groups (χ2=0.02, P=0.90,χ2=0.51, P=0.48, respectively). Ten cases from the control group manifested nasopharyngeal carcinoma;the same disease was not observed in the family group. Nasopharyngeal carcinoma detection rate was significantly higher in the control group than in the family group, but the difference was not statistically significant (χ2=1.05, P=0.31). Conclusion:a. Reactivation of the EB virus is not closely linked with genetic factors. b. The detection rate of NPC in FDR was lower compared with the general population after initial screening;thus, the rule of selective follow-up is not applicable for FDR.

OBJECTIVETo investigate the relationship between changes in high-risk populations and screening detected nasopharyngeal carcinoma (NPC) during the three-year follow-up of high-risk and moderate-risk groups at initial EB virus serology screening.

METHODSWe tested EB virus VCA-IgA and EBNA1-IgA antibody to identify the probability of suffering from NPC of the crowd. The high-risk and moderate-risk groups at initial screening in one county during 2009 to 2010 were followed-up once a year with EB virus serology testing. All the high-risk people during initial screening and follow-up were conducted with nasopharyngeal fiber endoscopy. Through the follow-up of three years, we analyzed changes in the number of high-risk group, detection rate of NPC in high-risk group, and tumor staging. Firstly detected NPC by screening was defined as screening group, and detected by following-up was defined as following-up group.

RESULTSA total of 404 participants were at high-risk and 1 041 participants were at moderate-risk group, 1 445 persons were in the group. All 404 persons were at high-risk at initial screening, the number of high-risk people during follow-up decreased from 371 to 187, 853 people of the all high-risk group were conducted with nasopharyngeal fiber endoscopy, and 38 cases of NPC were detected. NPC detection rate of high-risk group was 6.2% (25/404), 3.2% (12/371), 0.5% (1/188) and 0 (0/187) during the initial screening and three years follow-up respectively. The cumulative incidence of NPC in the high-risk and moderate-risk group were 7.7% (31/404) ,0.8% (8/1 041) . The early diagnosis rate of NPC in screening group and following-up group was 80% (20/25)and 11/13, respectively. With the primary tumor, the rate of T1 in screening group was higher than following-up group (80% to 38%, 20/25 to 5/13; P = 0.028). However, compared with following-up group, the rate of regional lymph node metastasis in screening group was higher (19/25 to 5/13; P = 0.035 ).

CONCLUSIONAlong with the high detection rate of early staging NPC in screening group and following-up group, the detection of NPC in high risk people is mainly at initial screening and the first year following-up and NPC detection rate thereafter is dropping significantly.

Antibodies, Viral ; Antigens, Viral ; Capsid Proteins ; Carcinoma ; Early Detection of Cancer ; Epstein-Barr Virus Nuclear Antigens ; Follow-Up Studies ; Herpesvirus 4, Human ; Humans ; Nasopharyngeal Neoplasms ; Neoplasm Staging ; Risk Factors