Molecular prognostication of nasopharyngeal carcinoma by quantitative analysis of circulating Epstein-Barr virus DNA

We investigated the prognostic implication of pretreatment plasma/serum EBV DNA concentration, as measured by real-time quantitative PCR, in nasophary ngeal carcinoma (NPC), In 91 prospectively recruited NPC patients, those wi th recurrence or metastasis within the first year after treatment had a hig her median plasma EBV DNA concentration than those without events (41,756 c opies/ml versus 5,807 copies/ml; P < 0.001, Mann-Whitney rank-sum test). In multivariate logistic regression analysis, plasma EBV DNA was an independe nt prognostic indicator for early clinical events [relative risk = 3.8 (95% confidence interval, 1.6-9.2 for each 10-fold increase in plasma EBV DNA c oncentration; P = 0.003)], In a second cohort of 139 NPC patients followed- up for a median period of 2,027 days (interquartile range, 597-2,335 days), serum EBV DNA was found to be a significant variable associated with NPC-r elated death in multivariate Cox's regression analysis [relative risk = 1.6 (95% confidence interval, 1.1-2.1 for each 10-fold increase in serum EBV D NA concentration; P = 0.007)]. The quantitation of circulating EBV DNA may thus allow improved prognostication of NPC.