Serologic biomarkers of Epstein-Barr virus correlate with TNM classification according to the seventh edition of the UICC/AJCC staging system for nasopharyngeal carcinoma

Abstract

This study aimed to investigate the association between Epstein-Barr virus (EBV)-related biomarkers and TNM classification according to the seventh edition of AJCC/UICC staging system for nasopharyngeal carcinoma. Serum VCA-IgA and EA-IgA titers and plasma EBV-DNA load were quantified at baseline in 779 patients; the rates of positivity and titers/load were compared by TNM classification. The VCA-IgA-positive rate was significantly associated with advanced N classification and stage; the EA-IgA-positive rate with advanced T and N classifications and stage; the EBV-DNA-positive rate with advanced T, N and M classifications and stage. The percentage of triple-positive patients was higher in patients with advanced TNM classification. The VCA-IgA titer and EA-IgA titer correlated positively with T classification, N classification and disease stage (1:117 in Stage I, 1:188.4 in Stage II, 1:231.12 in Stage III, 1:265.91 in Stage IV, and 1:18.34 in Stage I, 1:32.11 in Stage II, 1:34.77 in Stage III, 1:37.65 in Stage IV, respectively). EBV DNA load correlated positively with T, N and M classification and stage [median lg (EBV DNA): 0 (IQ range 0-1.85) in Stage I, 1.32 (0-3.51) in Stage II, 3.33 (0-4.30) in Stage III, 3.83 (2.85-4.71) in Stage IV]. Serum VCA-IgA/EA-IgA titers and plasma EBV DNA correlated strongly with TNM classification according to the seventh edition of the AJCC/UICC; however, plasma EBV DNA load could accurately predict metastatic disease. EBV serological biomarkers may enhance the accuracy of TNM staging and help to avoid excessive imaging examinations in routine evaluation.