A prospective trial of plasma EBV DNA for the screening of nasopharyngeal carcinoma

Abstract

Abstract Nasopharyngeal carcinoma (NPC) is common in the southern part of China. Making use of the close relationship between Epstein-Barr virus (EBV) infection and NPC, our group has established plasma EBV DNA as a tumor marker for NPC. In this prospective trial, we have investigated the efficacy of plasma EBV DNA analysis for identifying asymptomatic NPC. We screened 1318 subjects with no NPC symptoms with plasma EBV DNA analysis. At recruitment, 69 subjects (5.2%) had detectable EBV DNA in their plasma and 19 of these 69 subjects (28%) had persistently positive results after a median of 16 days. As a comparison, 86 (6.5%) were positive for IgA against EBV viral capsid antigen (VCA). Nasal endoscopy was carried out for all subjects with either a positive EBV DNA or VCA-IgA result. Three subjects were subsequently diagnosed of having NPC. All of them were positive for plasma EBV DNA at recruitment and on follow-up. In contrast, only one of them was positive for EBV VCA-IgA. Interestingly, in one patient, the cancer was too small to be visible in endoscopic examination but was identified in a subsequent magnetic resonance imaging (MRI) examination because of an increasing EBV DNA level. In summary, our results show that plasma EBV DNA is useful for the screening of NPC in asymptomatic individuals and the repetition of the analysis in 2 weeks is useful for identifying individuals with false positive results. This study is supported by the Michael and Betty Kadoorie Cancer Genetics Research Program. This talk is also presented as Poster B3.