EBV Conference 2008 Guangzhou - Baylor College of Medicine

205 (RegID: 1292)
Jaap Middeldorp
Institution: VU University medical center, Dept.Pathology
e-mail: j.middeldorp@vumc.nl
EBV-DNA LOAD MONITORING IN NASOPHARYNGEAL (NP) BRUSHINGS AND WHOLE
BLOOD DURING AND AFTER THERAPY OF NASOPHARYNGEAL CARCINOMA (NPC).
Linda Adham, Alida Harahap, I.Bing Tan, Sabine C Fleig, Astrid E Greijer and Jaap M Middeldorp.
Posterabstract:
NPC is a leading cancer in SE-Asia and nearly 100% EBV-associated, allowing use of EBV-based
diagnostic techniques. Recently we described a non-invasive NP-brush and whole blood approach
combined with EBV-DNA load measurement for the diagnosis of NPC (Stevens, 2005, 2006), yielding
better sensitivities in NP-brushings.
Purpose: In this study we evaluate the use EBV-DNA load monitoring in consecutive whole blood samples
and NP brushings taken at diagnosis and defined time points during and after chemoradiation therapy in a
series of 235 NPC patients. EBV-IgA serology was also done at all timepoints and routine clinical
examinations, CT-scan, nasendoscopy and biopsy were performed on a regular basis during follow-up.
Results: In all confirmed NPC cases, EBV-DNA load in NP-brushings at diagnosis showed strongly
elevated levels in nearly 98% of patients, with sometimes extreme high levels (>50x106c/brush), whereas
EBV-DNA was detectable in parallel blood samples mostly at low levels, being above the 2000c/ml
cut-off in only 40% of cases.
During therapy rapid and significant declines (>1000-fold) of EBV-DNA load in NP-brushings associated
with good clinical responses, whereas cases with partial response and persistent disease showed stable or
rising EBV-DNA levels. In patients without whole blood EBV-DNA load at diagnosis, fluctuating positive
levels were detected during therapy, but varied strongly per patient. Patients with detectable EBV-DNA
loads before therapy maintained fluctuating levels during and post- therapy.
EBV-IgA serology was not predictive of therapy outcome at short term but may be useful to (cheaply)
monitor for disease relapse at longer intervals post-therapy.
Conclusions: Our results indicate that EBV-DNA load monitoring in NP-brushings provides highly
relevant data reflecting tumor behaviour in situ and can be used for assessment of treatment effect.
EBV-DNA in blood is less informative, more variable and was useful in only a limited number of patients.
EBV-DNA in blood possibly reflects the apoptosis sensitivity/activity of the tumor, showing significant
individual variation. The non-invasive NP-brush technique allows repeated sampling without much
discomfort to the patient, and can replace the invasive biopsy, while providing more relevant information
on presence and activity EBV+ NPC in situ.
EBV Conference 2008 Guangzhou
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