Epstein-Barr virus serology as a potential screening marker for nasopharyngeal carcinoma among high-risk individuals from multiplex families in Taiwan.

BACKGROUND Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated cancer that is highly treatable when diagnosed early, with 5-year disease-free survival of approximately 90%. However, NPC is typically diagnosed at advanced stages, in which disease-free survival is <50%. There is, therefore, a need for clinical tools to assist in early NPC detection, particularly among high-risk individuals. METHODS We evaluated the ability of anti-EBV IgA antibodies to detect incident NPC among high-risk Taiwanese individuals. NPC cases (N = 21) and age- and sex-matched controls (N = 84) were selected. Serum collected before NPC diagnosis was tested for ELISA-based IgA antibodies against the following EBV peptides: EBNA1, VCAp18, EAp138, Ead_p47, and VCAp18 + EBNA1 peptide mixture. The sensitivity, specificity, and screening program parameters were calculated. RESULTS EBNA1 IgA had the best performance characteristics. At an optimized threshold value, EBNA1 IgA measured at baseline identified 80% of the high-risk individuals who developed NPC during follow-up (80% sensitivity). However, approximately 40% of high-risk individuals who did not develop NPC also tested positive (false positives). Application of EBNA1 IgA as a biomarker to detect incident NPC in a previously unscreened, high-risk population revealed that 164 individuals needed to be screened to detect 1 NPC and that 69 individuals tested positive per case detected. CONCLUSIONS EBNA1 IgA proved to be a sensitive biomarker for identifying incident NPC, but future work is warranted to develop more specific screening tools to decrease the number of false positives. IMPACT Results from this study could inform decisions about screening biomarkers and referral thresholds for future NPC early-detection program evaluations.