International Session 23 　　Malignant Tumors 2

Purpose: Epstein-Barr virus(EBV)IgA serology for viral capsid antigen(VCA)and early antigen(EA)aids early detection of nasopharyngeal cancer(NPC) , resulting in improved survival.We evaluated the diagnostic performance of a prefabricated immunofluorescent assay(IFA)for NPC screening in high-risk individuals.Methods: Sera from 96 biopsy-proven patients with NPC diagnosed at the outpatient clinic and 96 healthy family members were tested for EBV-VCA IgA and EBV-EA IgA using the prefabricated IFA from EUROIMMUN(EI)and the traditional immunofluorescence method.Results and discussion: The AUC of EI EBV-VCA IgA and EBV-EA IgA was 0 907(95 confidence intervalCI : 0 894-0 965)and 0 898(95 CI: 0 848-0 947) , respectively.Combined testing with the prefabricated assay at a threshold of VCA 1: 320 or EA 1: 10 showed 92.7 sensitivity and 81 2 specificity.Overall, the traditional EBV-EA IgA assay demonstrated the best accuracy(sensitivity 91 7 and specificity 96 9)at a threshold of 1: 5 Conclusion: While the traditional IFA method was more accurate, the prefabricated IFA test kit can be a useful tool for NPC screening in high-risk populations.