Clinical significance of plasma Epstein-Barr Virus DNA loads in a large cohort of Malaysian patients with nasopharyngeal carcinoma.
BACKGROUND
Nasopharyngeal carcinoma (NPC) is an Epstein-Barr Virus (EBV)-associated cancer that is the fifth most common cancer in Malaysia. Early and accurate diagnoses are critical for patient prognosis. Unfortunately, early detection of NPC is still a challenge and the cost of more accurate imaging protocols is prohibitive in developing countries like Malaysia.


OBJECTIVE
To evaluate the clinical values of pre-treatment plasma EBV DNA levels in Malaysian NPC patients.


METHODS
Plasma EBV DNA levels were measured by quantitative PCR (Q-PCR) in a large and multi-ethnic cohort of Malaysian patients with NPC (n=459) and 72 control subjects.


RESULTS
We show for the first time that, compared to controls, NPC patients with stage I disease had significantly higher levels of EBV DNA (p<0.001). Further, the median level of plasma EBV DNA in stage IV patients with distant metastasis was >9-fold higher than those without systemic spread (p=0.001), suggesting plasma EBV DNA measurement could aid in the diagnosis of metastatic disease in advanced cases. Further, using a cut-off value of 8000 copies/mL, we demonstrate that EBV DNA level is a strong predictor for overall survival of NPC patients.


CONCLUSIONS
Our data show that pre-treatment plasma EBV DNA is a potential biomarker for early stage and metastatic NPC. We conclude that the quantification of plasma EBV DNA is a useful tool in developing countries to stratify patients for MRI or PET/CT scans where such imaging protocol is not routinely applied.
Cancer Research Initiatives Foundation, Subang Jaya, Malaysia.
San Jiun
SJ
Chai
Kin Choo
KC
Pua
Amyza
A
Saleh
Yoke Yeow
YY
Yap
Paul V H
PV
Lim
Selva Kumar
SK
Subramaniam
Chee Lun
CL
Lum
Gopala
G
Krishnan
Wan Rozita Wan
WR
Mahiyuddin
Soo-Hwang
SH
Teo
Alan S B
AS
Khoo
Lee Fah
LF
Yap
D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D016022:Case-Control Studies; D004279:DNA, Viral / Q000097:blood*; D020031:Epstein-Barr Virus Infections / Q000097:blood / Q000453:epidemiology / Q000821:virology*; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology / Q000821:virology*; D009362:Neoplasm Metastasis; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
D004279:DNA, Viral