Epstein–Barr virus dynamics and its prognostic impact on nasopharyngeal cancers in a non-endemic region

Abstract

Background: Epstein-Barr virus (EBV) DNA quantification in nasopharyngeal cancer (NPC) is an indicator of the tumour burden, stage and survival. Although EBV dynamics in endemic regions has been extensively studied and reported, the data from non-endemic regions is sparse. This study attempts to investigate the EBV dynamics in NPC patients from a non-endemic region and also to identify the factors impacting the outcomes. Materials and methods:This was a prospective observational study conducted at a tertiary care centre in South India and enrolled patients with non-metastatic, biopsy proven NPC, who were suitable for radical chemo-radiotherapy with or without induction chemotherapy. Two blood samples, one prior to initiation of any anticancer treatment, and second at 6 weeks post treatment, were collected to quantify EBV DNA using real-time quantitative polymerase chain reaction. Antibodies against EBV viral capsid antigen (EBV VCA IgM), EBV Early Antigen (EBV EA IgG) and EBV Nuclear Antigen (EBV EBNA IgG) were also measured in the sample. The impact of EBV dynamics on the outcomes was then analysed. Results:The study included a total of 35 patients. Thirty-three had identifiable EBV DNA (94.3%) and a histological diagnosis of non-keratinising undifferentiated type of squamous cell carcinoma. There was no correlation between the EBV DNA and anti-EBV antibodies. There was a significant association between composite stage and pre-treatment DNA titre (p = 0.030). The mean EBV DNA titre was lower for patients with no clinically demonstrable disease at last follow-up and the reduction in EBV DNA titres was significant (p = 0.020) for those patients who remained disease free. Conclusion:Plasma EBV DNA is an accurate and reliable biomarker for NPC for WHO type 2 and 3 tumours even in non-endemic regions.

Saliva biopsy: Detecting the difference of EBV DNA methylation in the diagnosis of nasopharyngeal carcinoma

“…It seemed that most of EBV DNA molecules in saliva from post-therapy patients were again returned to an extent normal physiological status and mainly from viral particles at oropharynx. The same as EBV DNA load in plasma, [43][44][45] EBV DNA methylation in saliva might be used to reflect the disease progress in the future. Besides, our results showed there was a significant increase of EBV DNA methylated density in salivary samples from patients with early stage (I/II) and T1/T2 subgroup (Figure 4B).…”

Resources for Human Health from the Plant Kingdom: The Potential Role of the Flavonoid Apigenin in Cancer Counteraction

“…The EBV primarily infects circulating human B cells and is kept in a latent state. The lytic reactivation of the EBV plays an important role in various human malignancies, being highly correlated with cancer progression, poor prognosis, and tumor recurrence of NPC, peculiarly [ 39 ]. The ability of apigenin to inhibit the lytic induction of the EBV, reactivation in the lytic cycle, and virion production by EBV-positive NPC cells, appears to be beneficial for cancer prevention [ 40 , 41 ].…”