To assess the role of polymerase chain reaction (pCR) quantitative estimation of plasma
Epstein-Barr viral (EPV) DNA load as a non-invasive diagnostic and/or prognostic modality for Egyptian
nasopharyngeal carcinoma (NPC) patients. Patients & Methods: All patients underwent fiberoptic direct
nasopharyngoscopy for nasopharyngeal inspection and to obtained tissue biopsy of a suspicious growth for pathological
examination and grading according to WHO pathological grading. Primary tumor extent was evaluated by both MRI
and CT scanning. Two venous blood samples were collected; one prior to initiation of therapy and at 4-weeks after the
last session of radiotherapy for quantitative PCR determination of EBV plasma DNA loads. For primary treatment:
external radiotherapy and brachytherapy boost for patients with lesions staged TI/T2 NO MO; external radiotherapy +
concomitant chemotherapy +adjuvant chemotherapy and uni- or bilateral neck block dissection for persistent nodal
disease at 3 months for patients with nodal lesions. Follow-up included nasopharyngoscopy three-monthly for 2 years.
Results: The study included 45 patients; 23 patients (51.1%) had nodal involvement. According to TNM staging; 3
patients had carcinoma in situ, 6 had stage-I, 12 had stage-II. 15 had stage-III and 9 patients had stage-IV lesions; 22
lesions were WHO grade 1, 14 were grade IT and 9 lesions were WHO grade III. There was a positive significant
correlation between WHO pathological and mm staging. MR1 detected local invasion in 12 patients (26.7%).
Qualitative PCR detected EBV viral DNA in all blood samples. Using Quantitative PCR technique. mean EBV DNA
plasma load was 2188±642 copies/nil. There was a positive significant correlation between mean plasma viral load and
TNM stage and WHO grade. Post-treatment quantitative PCR detected EBV DNA only in 0 (22.2%) patients with a
mean plasma level of 61.5t33.7 copies/nil that was significantly lower than pre-treatment levels. Conclusion: PCR
quantitative estimation of plasma Epstein-Barr viral DNA load is a valuable diagnostic test that showed a positive
significant correlation with both TNM staging and WHO pathological grading of patients with NPC and could be used
to assess the response to applied therapeutic modalities. Considering Egypt as a non-endemic area for NPC, quantitative
estimation of EBV plasma load could be used as screening test for patients presenting by symptoms suspicious of NPC.
[Ahmed Houssein, Mosad M. Odah, Eman A. Bath, Mohamed Al-Sherbiny and Tamer EI-Shiehk. Serum Epstein
Barr Virus as a Biomarker in Nasopharyngeal Carcinoma. |
