The whole-blood Epstein-Barr virus DNA can serve as a valuable molecular marker for diagnosis and prognosis prediction of nasopharyngeal carcinoma.

The clinical significance and prognostic role of whole-blood EBV-DNA in EBV-associated nasopharyngeal carcinoma (NPC) have not been thoroughly investigated. This study aims to explore the diagnostic and prognostic value of EBV-DNA for NPC in a non-endemic region of China. We enrolled patients with chronic active EBV infection (CAEBV), nasopharyngitis (NA), extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT), and NPC. Demographic and clinical data were collected and the diagnostic and prognostic values of EBV-DNA were analyzed. Immunohistochemistry was performed to detect EBV-encoded small ribonucleic acids (EBER), as well as the expression of p53, Ki-67, and epidermal growth factor receptor (EGFR). The levels of pretreatment Epstein-Barr virus DNA (preEBV-DNA) in new NPC cases were found to differ from those in other diseases and exhibited varying age distributions. The threshold value of preEBV-DNA for distinguishing NPC from CAEBV and NA was determined. We confirmed that epistaxis, diabetes mellitus, T3N2 or T4N0-2 stage, and IgM positivity were associated with higher levels of preEBV-DNA, and identified risk factors associated with the prognosis of locoregionally advanced NPC (La-NPC). Patients with intermittently or persistently positive EBV-DNA (IPCP), higher preEBV-DNA levels, and positive Epstein-Barr virus-encoded small RNA (EBER) status (EBERpos) had worse survival. New cases of NPC with elevated levels of EBV in the whole-blood and positive EBER status were shown to have a poor prognosis upon progression to La-NPC. EBV-DNA was found to be an indicator for predicting prognosis in La-NPC and could also be used to distinguish new NPC cases.