[The value of plasma EBV-DNA testing in high-risk group of nasopharyngeal carcinoma in the nasal endoscopy].

Objective:The aim of this study is to evaluate the level of plasma EBV DNA and nasal endoscopy in high risk population of nasopharyngeal carcinoma, and to explore the value of EBV DNA testing in nasal endoscopy. Method:The nasopharyngeal carcinoma was screened in High-incidence Area of Zhongshan City. EBV antibody was detected by ELISA, and 427 patients with high risk of nasopharyngeal carcinoma were identified. In the high risk population the plasma EBV-DNA was measured using Fluorescent quantitative PCR, and all patients were used nasal endoscopy in the first two years. The application value of EBV DNA and nasopharyngeal endoscopic biopsy were analyzed. Result:There were 427 NPC high risk population in first screening. The rates of nasopharyngeal biopsy in EBV DNA positive and EBV DNA negative population were 90.2% (55/61) and 13.9% (51/366), respectively. The rate of NPC nasopharyngeal biopsy in EBV DNA positive population was higher than that in EBV DNA negative population (P<0.01). The rate of NPC detection in EBV DNA positive group (60.7%) was higher than that (3.3%) in EBV DNA negative population (P<0.01). In first year follow up, there were 286 NPC high risk population. The rates of nasopharyngeal biopsy in EBV DNA positive and EBV DNA negative population were 91.2% (31/34) and 11.9% (30/252), respectively. The rate of NPC nasopharyngeal biopsy in EBV DNA positive population was higher than that in EBV DNA negative population (P<0.01). The rate of NPC detection in EBV DNA positive group (17.6%) was higher than that (1.6%) in EBV DNA negative population (P<0.01). The positive predicative value of serological risk assessment was 8.3% (59/713), but for NPC high risk group, adding quantitative analysis of plasma EBV DNA, the positive predicative value was 45.3% (43/95). The early diagnosis rates in EBV DNA positive and EBV DNA negative population were 79.1% (34/43) and 93.8% (15/16), respectively. There was no significant difference in early diagnosis rates in two groups (P>0.05). Conclusion:The positive rate of plasma EBV DNA in high risk group of nasopharyngeal carcinoma may be helpful for nasal endoscopic nasopharyngeal biopsy, which can greatly improve the positive predictive value of high risk population of nasopharyngeal carcinoma. For NPC high risk population, Therefore, EBV DNA positive population are the focus for NPC screening.