Rapid clearance of plasma Epstein-Barr virus DNA after surgical treatment of nasopharyngeal carcinoma.
OBJECTIVE
Circulating EBV DNA analysis has been shown to be valuable in the detection, prognostication, and monitoring of nasopharyngeal carcinoma (NPC) patients. A previous study has shown that, after radiotherapy, plasma EBV DNA levels of NPC patients would decline exponentially with a median half-life of 3.8 days. We postulate that this decline in plasma EBV DNA reflects the decrease in cancer cell population and, therefore, the rate of decline reflects the radiosensitivity of the tumor. However, this postulation would hold true only if EBV DNA is rapidly eliminated from the circulation. In this study, we determined the in vivo elimination rate of plasma EBV DNA in NPC patients.


METHODS
We monitored the level of plasma EBV DNA in NPC patients during and after surgical resection of NPC. The half-life of plasma EBV DNA was then calculated by plotting the natural logarithm of EBV DNA concentrations against time.


RESULTS
The median half-life of plasma EBV DNA after surgical resection of NPC was 139 min. After a median follow-up of 6.7 days, EBV DNA was undetectable in 8 of 11 patients. One of 8 patients with undectable EBV DNA and all of the patients with detectable EBV DNA developed clinical relapse.


CONCLUSIONS
The in vivo elimination of EBV DNA is very rapid after surgical resection of NPC. The failure of complete and rapid elimination of EBV DNA from the circulation predicts disease recurrence.
To
Edward W H
EW
Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong Special Administrative Region, China.
Chan
K C Allen
KC
Leung
Sing-Fai
SF
Chan
Lisa Y S
LY
To
Ka-Fai
KF
Chan
Anthony T C
AT
Johnson
Philip J
PJ
Lo
Y M Dennis
YM
D014408:Biomarkers, Tumor; D002277:Carcinoma / Q000601:surgery* / Q000821:virology*; D004279:DNA, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D007700:Kinetics; D008962:Models, Theoretical; D009303:Nasopharyngeal Neoplasms / Q000601:surgery* / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D014408:Biomarkers, Tumor; D004279:DNA, Viral