title: Diagnostic and prognostic implications of circulating cell-free Epstein-Barr virus DNA in natural killer/T-cell lymphoma.
abstract: OBJECTIVE
  Natural killer/T-cell (NK/T-cell) lymphoma is a highly aggressive tumor for which no serological tumor marker has yet been established to be useful clinically. We investigated the potential of circulating EBV DNA as a tumor marker for this malignancy.
  
  
  METHODS
  A real-time quantitative PCR assay was used to measure circulating EBV DNA.
  
  
  RESULTS
  Plasma EBV DNA levels were measured in 18 patients with NK/T-cell lymphoma at presentation and during therapy. Plasma EBV DNA was detected in 17 of the 18 patients (median, 659 copies/ml; interquartile range, 181-17,042 copies/ml) but in none of 35 control subjects (p < 0.0001). Serial measurements of plasma EBV DNA levels during therapy showed a close correlation between clinical response and changes in plasma EBV DNA levels. Clinically responding patients showed a fall of plasma EBV DNA levels to low or undetectable levels, whereas those who failed therapy showed a rapid increase in plasma EBV DNA levels. Most importantly, patients with high baseline plasma EBV DNA levels (> or = 600 copies/ml) demonstrated a significantly inferior survival than those with low baseline plasma EBV DNA (< 600 copies/ml; 21% versus 78%; P = 0.024).
  
  
  CONCLUSIONS
  Plasma EBV DNA, as measured by real-time quantitative PCR, is a useful tumor marker for diagnosis, disease monitoring, and prediction of outcome in patients with NK/T-cell lymphoma.
authors.affiliation: Department of Clinical Oncology and The Sir Y. K. Pao Cancer Centre, The Chinese University of Hong Kong, Prince of Wales Hospital, The New Territories, Hong Kong Special Administrative Region, China.
authors.forename: Kenny I K
authors.initials: KI
authors.lastname: Lei
authors.forename: Lisa Y S
authors.initials: LY
authors.lastname: Chan
authors.forename: Wing-Yee
authors.initials: WY
authors.lastname: Chan
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Johnson
authors.forename: Y M Dennis
authors.initials: YM
authors.lastname: Lo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004279:DNA, Viral / Q000097:blood*; D020031:Epstein-Barr Virus Infections / Q000821:virology*; D005260:Female; D005500:Follow-Up Studies; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D007694:Killer Cells, Natural / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000175:diagnosis / Q000401:mortality / Q000821:virology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011379:Prognosis; D015996:Survival Rate
chemical_list: D004279:DNA, Viral