| Nasopharyngeal carcinoma (NPC; WHO type II/III) is a highly prevalent cancer in China , SE-Asia , Indonesia and Northern Africa and is 100% associated with EBV. Diagnosis of NPC requires an invasive biopsy, which cannot be repeated easily without discomfort for the patient. We investigated the value of serology and EBV-DNA load in blood of NPC patients and various regional controls. We found EBV-serology to be reliable parameter in >90% of patients 1 . In blood, using real-time PCR, we found detectable EBV-DNA in about 80% of NPC patients, with generally low values in 60% of cases 2 . EBV-DNA appeared to be highly fragmented and was not related to TNM-stage. EBV-RNA was not detectable in blood, suggesting absence of circulating tumour cells 2 . Because EBV-DNA levels had no relation to serological responses, both can be used as independent parameters. We conclude that EBV-DNA in blood of NPC patients is derived from necrotising tumour material and has limited value for primary diagnosis. The prognostic value of circulating EBV-DNA is under investigation by following patients with initial high EBV-DNA load (Adham et al.). In a caucasian NPC patient at VUmc, we demonstrated the prognostic value of EBV IgA serology for predicting late distant metastasis, whereas EBV-DNA load was of no value 3 . A new non-invasive nasopharyngeal (NP) brushing method was developed for assessment of tumour related (EBV) markers at the site of primary tumour development,. Importantly, we found that NPC patients had significantly higher levels of EBV-DNA and specific EBV-RNA profiles in NP-brush extracts when compared to healthy EBV carriers and non-NPC tumour patients 4 . In follow-up studies of NPC patients (N=150) during chemo-radiation therapy we demonstrated a direct correlation between EBV-DNA load and clinical responses (Adham et al., in progress). We also showed that in NP brush samples tumour cells could be identified by cytology with or without EBV monoclonal antibody staining. NP brushing proves to be a promising non-invasive method for diagnosis and monitoring in NPC, with options similar to cervical carcinoma screening. |
