Plasma epstein‐barr virus DNA concentration and clearance rate as novel prognostic factors for metastatic nasopharyngeal carcinoma

To investigate the pretreatment copy number and the clearance rate of plasma Epstein-Barr virus (EBV) DNA as novel prognostic outcome markers for metastatic nasopharyngeal carcinoma (NPC).Seventy-three patients with metastatic NPC were treated at outpatient department. Plasma EBV DNA concentrations and half-life values of plasma viral clearance rates, were determined by real-time quantitative polymerase chain reaction.Treatment response evaluated after 3 to 6 months of treatment showed that the overall response rate was 53.5%. The pretreatment plasma EBV DNA concentrations and the half-life of plasma EBV DNA clearance rates had significant effects on treatment response and overall survival prediction. In the chemotherapy regimen, gemcitabine plus cisplatin had a better treatment outcome than the cisplatin plus oral UFT and calcium folinate-based regimens.The pretreatment plasma EBV DNA copy number and their clearance rates are significant predictors for NPC treatment outcome.