Laboratory markers of tumor burden in nasopharyngeal carcinoma: A comparison of viral load and serologic tests for Epstein-Barr virus

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Virological Markers in Epstein–Barr Virus-Associated Diseases

Epstein–Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world’s population. After primary infection—responsible for infectious mononucleosis in young adults—the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

Design of InnoPrimers-Duplex Real-Time PCR for Detection and Treatment Response Prediction of EBV-Associated Nasopharyngeal Carcinoma Circulating Genetic Biomarker

Nasopharyngeal carcinoma (NPC) is an epithelial tumor with high prevalence in southern China and Southeast Asia. NPC is well associated with the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) 30 bp deletion by having its vital role in increased tumorigenicity and decreased immune recognition of EBV-related tumors. This study developed an InnoPrimers-duplex qPCR for detection of NPC blood circulating LMP1 30 bp deletion genetic biomarker for early diagnosis and treatment response prediction of NPC patients. The analytical and diagnostic evaluation and treatment response prediction were conducted using NPC patients’ whole blood (WB) and tissue samples and non-NPC cancer patients and healthy individuals’ WB samples. The assay was able to detect as low as 20 ag DNA per reaction (equivalent to 173 copies) with high specificity against broad reference microorganisms and archive NPC biopsy tissue and FNA samples. The diagnostic sensitivity and specificity were 83.3% and 100%, respectively. The 30 bp deletion genetic biomarker was found to be a good prognostic biomarker associated with overall clinical outcome of NPC WHO type III patients. This sensitive and specific assay can help clinicians in early diagnosis and treatment response prediction of NPC patients, which will enhance treatment outcome and lead to better life-saving.

A systematic review and recommendations on the use of plasma EBV DNA for nasopharyngeal carcinoma

INTRODUCTION

Nasopharyngeal carcinoma (NPC) is an endemic malignancy in Southeast Asia, particularly Southern China. The classical non-keratinising cell type is almost unanimously associated with latent Epstein-Barr virus (EBV) infection. Circulating plasma EBV DNA can be a useful biomarker in various clinical aspects, but comprehensive recommendations and international guidelines are still lacking. We conducted a systematic review of all original articles on the clinical application of plasma EBV DNA for NPC; we further evaluated its strengths and limitations for consideration as standard recommendations.

METHODS

The search terms 'nasopharyngeal OR nasopharynx', and 'plasma EBV DNA OR cell-free EBV OR cfEBV' were used to identify full-length articles published up to December 2020 in the English literature. Three authors independently reviewed the article titles, removed duplicates and reviewed the remaining articles for eligibility.

RESULTS

A total of 81 articles met the eligibility criteria. Based on the levels of evidence and grades of recommendation assessed, it is worth considering the inclusion of plasma EBV DNA in screening, pre-treatment work-up for enhancing prognostication and tailoring of treatment strategy, monitoring during radical treatment, post-treatment surveillance for early detection of relapse, and monitoring during salvage treatment for recurrent or metastatic NPC. One major limitation is the methodology of measurement requiring harmonisation for consistent comparability.

CONCLUSIONS

The current comprehensive review supports the inclusion of plasma EBV DNA in international guidelines in the clinical aspects listed, but methodological issues must be resolved before global application.

Clinical utility of Epstein-Barr virus DNA and other liquid biopsy markers in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor ubiquitously associated with the Epstein-Barr virus (EBV), which is highly prevalent in South China, Southeast Asia, and North Africa. Despite being a highly radio-sensitive and treatable cancer, a majority of NPC patients are diagnosed in their advanced stage, and locoregional and distant relapses following definitive treatment contribute largely to cancer-specific mortality among these patients. Given that EBV-driven NPC is the predominant variant seen in endemic regions, various EBV detection methods have been developed and are utilized in screening, prognostication, and post-treatment surveillance of NPC patients. While the Immunoglobulin A (IgA) serology assay is the most extensively studied EBV detection method, the detection of plasma EBV DNA released during replication or cellular apoptosis has shown superior outcomes in endemic population screening, prognostication, and detection of distant relapse. Furthermore, there is emerging evidence on the use of circulating tumor cells, microRNAs, DNA hypermethylation, and combination assays in various clinical scenarios. Herein, this paper provides a comprehensive overview of the relevant studies using various EBV detection techniques in the management of NPC. Specifically, the recent advances, clinical evidence, and challenges associated with the clinical application of EBV liquid biopsies in population screening, prognostication, and surveillance of NPC are presented.

Risk stratification for nasopharyngeal carcinoma: a real-world study based on locoregional extension patterns and Epstein-Barr virus DNA load

Aim:

The present study aimed to evaluate the combined value of locoregional extension patterns (LEPs) and circulating cell-free Epstein–Barr virus (cf EBV) DNA for risk stratification of locoregionally advanced nasopharyngeal carcinoma (LA-NPC) to better guide therapeutic strategies.

Methods:

A total of 7227 cases of LA-NPC were reviewed retrospectively and classified into six groups according to their LEP (ascending, descending, or mixed type) and pre-treatment cf EBV-DNA load (⩾ versus <4000 copy/ml). Using a supervised statistical clustering approach, patients in the six groups were clustered into low, intermediate, and high-risk clusters. Progression-free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were calculated using the Kaplan–Meier method and differences were compared using the log-rank test.

Results:

Survival curves for the low, intermediate, and high-risk clusters were significantly different for all endpoints. The 5-year survival rate for the low, intermediate, and high-risk clusters, respectively, were: PFS (83.5%, 73.2%, 62.6%, p < 0.001), OS (91.0%, 82.7%, 73.2%, p < 0.001), DMFS (92.3%, 83.0%, 73.4%, p < 0.001), and LRRFS (91.0%, 88.0%, 83.3%, p < 0.001). The risk clusters acted as independent prognostic factors for all endpoints. Among the patients in the high-risk cluster, neoadjuvant chemotherapy combined with concurrent chemoradiotherapy (CCRT) significantly improved the patients 5-year PFS (66.4% versus 57.9%, p = 0.014), OS (77.6% versus 68.6%; p < 0.002), and DMFS (76.6% versus 70.6%; p = 0.028) compared with those treated with CCRT.

Conclusion:

Our results could facilitate the development of risk-stratification and risk-adapted therapeutic strategies for patients with LA-NPC.

Clinical Implications of Plasma Epstein-Barr Virus DNA in Children and Adolescent Nasopharyngeal Carcinoma Patients Receiving Intensity-Modulated Radiotherapy

Background: Plasma Epstein–Barr virus (EBV) DNA has been determined as a prognostic factor in adult nasopharyngeal carcinoma (NPC) patients. This study was designed to evaluate the prognostic value of plasma pretreatment EBV DNA in children and adolescent NPC patients receiving intensity-modulated radiotherapy (IMRT).

Methods: Pretreatment EBV DNA was retrospectively assessed in 147 children with newly diagnosed, non-metastatic NPC. All patients were treated using IMRT. Receiver operating characteristic (ROC) curve was used to identify the optimal EBV DNA cutoff point. Prognostic value was examined using a multivariate Cox proportional hazards model.

Results: The median follow-up for the entire cohort was 58 months (range, 10–119 months), and the 5-year survival rates for all patients were as follows: overall survival (OS), 88.7%; locoregional relapse-free survival, 95.2%; distant metastasis-free survival (DMFS), 84.8%; and disease-free survival (DFS), 81.5%. For ROC curve analysis, the optimal cutoff value of pretreatment EBV DNA load for DFS was 40,000 copies/mL. High plasma EBV DNA was significantly associated with poorer 5-year DMFS (70.6 vs. 89.1%, P = 0.003) and DFS (63.9 vs. 86.9%, P < 0.001). In multivariate analysis, high plasma EBV DNA was an independent predictor for DMFS and DFS.

Conclusions: Pretreatment EBV DNA level was a powerful prognostic discriminator for DMFS and DFS in children and adolescent NPC patients treated with IMRT.

APOBEC-mediated DNA alterations: A possible new mechanism of carcinogenesis in EBV-positive gastric cancer

Mechanisms of viral oncogenesis are diverse and include the off-target activity of enzymes expressed by the infected cells, which evolved to target viral genomes for controlling their infection. Among these enzymes, the single-strand DNA editing capability of APOBECs represent a well-conserved viral infection response that can also cause untoward mutations in the host DNA. Here we show, after evaluating somatic single-nucleotide variations and transcriptome data in 240 gastric cancer samples, a positive correlation between APOBEC3s mRNA-expression and the APOBEC-mutation signature, both increased in EBV+ tumors. The correlation was reinforced by the observation of APOBEC mutations preferentially occurring in the genomic loci of the most active transcripts. This EBV infection and APOBEC3 mutation-signature axis were confirmed in a validation cohort of 112 gastric cancer patients. Our findings suggest that APOBEC3 upregulation in EBV+ cancer may boost the mutation load, providing further clues to the mechanisms of EBV-induced gastric carcinogenesis. After further validation, this EBV-APOBEC axis may prove to be a secondary driving force in the mutational evolution of EBV+ gastric tumors, whose consequences in terms of prognosis and treatment implications should be vetted.

Clinical value of a plasma Epstein-Barr virus DNA assay in the diagnosis of recurrent or metastatic nasopharyngeal carcinoma: a meta-analysis

BACKGROUND

To evaluate the diagnostic value of Epstein-Barr virus (EBV) DNA in nasopharyngeal carcinoma (NPC) patients with locoregional or distant recurrence.

METHODS

Articles related to the diagnosis of recurrent or metastatic NPC by the detection of EBV DNA in plasma or serum were retrieved from different databases. Sensitivity, specificity, summary receiver operating characteristic (SROC) curves, and likelihood ratios were pooled to assess the diagnostic value of individual diagnostic tests.

RESULTS

This meta-analysis pooled 25 eligible studies including 2496 patients with NPC. The sensitivity, specificity, positive likelihood ratio (+LR), and negative likelihood ratio (-LR) of EBV DNA in the diagnosis of NPC were 0.858 (95% confidence interval (CI): 0.801-0.901), 0.890 (95% CI: 0.866-0.909), 7.782 (95% CI: 6.423-9.429) and 0.159 (95% CI: 0.112-0.226), respectively. The diagnostic odds ratio (DOR) was 48.865 (95% CI: 31.903-74.845). The SROC for EBV DNA detection was 0.93 (95% CI: 0.90-0.95).

CONCLUSION

The detection of EBV DNA for the diagnosis of recurrent or metastatic NPC has good sensitivity and specificity and might be helpful in monitoring recurrent or metastatic NPC.

Extracellular Vesicles in Epstein-Barr Virus Pathogenesis

Purpose of review

Epstein-Barr virus (EBV) is a known determinant for numerous malignancies and may contribute to autoimmune diseases. The underlining mechanisms behind EBV pathologies is not completely understood. Recently, extracellular vesicles (EVs) released from infected cells have been found to produce profound effects on cellular microenvironments. Therefore, in this review we sought to critically evaluate the roles of EVs in EBV pathogenesis and assess their potential therapeutic and diagnostic utility.

Recent findings

EBV-altered EVs are capable of activating signaling cascades and phenotypic changes in recipient cells through the transfer of viral proteins and RNAs. Moreover, several EV-associated microRNAs have encouraging prognostic or diagnostic potential in EBV-associated cancers.

Summary

Current evidence suggests that EBV-modified EVs affect viral pathogenesis and cancer progression. However, further research is needed to investigate the direct role of both viral and host products on recipient cells and the mechanisms driving viral protein and RNA EV packaging and content modification.

Plasma Epstein-Barr virus DNA as an archetypal circulating tumour DNA marker

Analysis of circulating tumour DNA (ctDNA), as one type of ‘liquid biopsy’, has recently attracted great attention. Researchers are exploring many potential applications of liquid biopsy in many different types of cancer. In particular, it is of biological interest and clinical relevance to study the molecular characteristics of ctDNA. For such purposes, plasma Epstein–Barr virus (EBV) DNA from patients with nasopharyngeal carcinoma (NPC) would provide a good model to understand the biological properties and clinical applications of ctDNA in general. The strong association between EBV and NPC in endemic regions has made plasma EBV DNA a robust biomarker for this cancer. There are many clinical utilities of plasma EBV DNA analysis in NPC diagnostics. Its role in prognostication and surveillance of recurrence is well established. Plasma EBV DNA has also been validated for screening NPC in a recent large‐scale prospective study. Indeed, plasma EBV DNA could be regarded as an archetypal ctDNA marker. In this review, we discuss the biological properties of plasma EBV DNA from NPC samples and also the clinical applications of plasma EBV DNA analysis in the management of NPC. Of note, the recently reported size analysis of plasma EBV DNA in patients with NPC has highlighted size as an important analytical parameter of ctDNA and demonstrated clinical value in improving the diagnostic performance of an EBV DNA‐based NPC screening test. Such insights into ctDNA analysis (including size profiling) may help its full potential in cancer diagnostics for other types of cancer to be realised. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

[Diagnostics of nasopharyngeal carcinoma with Epstein-Barr virus (Herpesviridae, Lymphocryptovirus, HHV-4) serological and molecular markers in cases of undetected primary tumor location.]

INTRODUCTION

The reasons of late diagnosis of nasopharyngeal carcinoma (NPC) are the long asymptomatic course of the pathological process, the anatomical structure of the nasopharynx, often small, visually and endoscopically undetectable tumor and other factors. It is proved that the Epstein-Barr virus (EBV) is an etiological agent in the most common undifferentiated non-keratinizing histological type of NPC (uNPC).

OBJECTIVES

The aim of the work was to assess the significance of diagnostic markers of EBV (titers of humoral antibodies to the virus and the concentration of viral DNA in plasma) for the diagnosis of uNPC in a group of patients with metastatic lesions of the cervical lymph nodes without an identified localization of the primary tumor focus.

MATERIAL AND METHODS

The material for the study was blood plasma of 83 patients with metastatic lesions of the cervical lymph nodes and not established localization of the primary tumor. Plasma samples were tested for the anti-EBV IgG and IgA antibody content and titers and the concentration of viral DNA.

RESULTS AND DISCUSSION

The data obtained indicate that the parallel testing of blood plasma for EBV-specific antibodies and viral load is a useful tool for preliminary screening of uNPC patients. The final diagnosis is confirmed by the data of subsequent morphological and instrumental studies. Several examples also show that the concentration of viral DNA in the blood plasma of patients with uNPC reflects the effect of the therapy and the prognosis of the disease: remission, stabilization of the tumor process, relapse or metastasis.

CONCLUSION

Although the titers of virus-specific antibodies are found to reflect clinical manifestations of the disease less accurately than the plasma concentrations of viral DNA, serological markers are extremely important for the preliminary diagnostics of uNPC in cases of undetected primary tumor location. They are also useful for primary screening of this neoplasm among individuals at risk.

Vesicle-bound EBV-BART13-3p miRNA in circulation distinguishes nasopharyngeal from other head and neck cancer and asymptomatic EBV-infections

Cell‐free microRNA (miRNA) in biofluids released by tumors in either protein or vesicle‐bound form, represent promising minimally‐invasive cancer biomarkers. However, a highly abundant non‐tumor background in human plasma and serum complicates the discovery and detection of tumor‐selective circulating miRNAs. We performed small RNA sequencing on serum and plasma RNA from Nasopharyngeal Carcinoma (NPC) patients. Collectively, Epstein Barr virus‐encoded miRNAs, more so than endogenous miRNAs, signify presence of NPC. However, RNAseq‐based EBV miRNA profiles differ between NPC patients, suggesting inter‐tumor heterogeneity or divergent secretory characteristics. We determined with sensitive qRT‐PCR assays that EBV miRNAs BART7‐3p, BART9‐3p and BART13‐3p are actively secreted by C666.1 NPC cells bound to extracellular vesicles (EVs) and soluble ribonucleoprotein complexes. Importantly, these miRNAs are expressed in all primary NPC tumor biopsies and readily detected in nasopharyngeal brushings from both early and late‐stage NPC patients. Increased levels of BART7‐3p, BART9‐3p and particularly BART13‐3p, distinguish NPC patient sera from healthy controls. Receiver operating characteristic curve analysis using sera from endemic NPC patients, other head and neck cancers and individuals with asymptomatic EBV‐infections reveals a superior diagnostic performance of EBV miRNAs over anti‐EBNA1 IgA serology and EBV‐DNA load (AUC 0.87–0.96 vs 0.86 and 0.66 respectively). The high specificity of circulating EBV‐BART13‐3p (97%) for NPC detection is in agreement with active secretion from NPC tumor cells. We conclude EV‐bound BART13‐3p in circulation is a promising, NPC‐selective, biomarker that should be considered as part of a screening strategy to identify NPC in endemic regions.

What's new?

Analysis of DNA from human tumor viruses in patient blood is a non‐invasive screening method for individuals at risk for developing cancer. A drawback is over‐diagnosis as these sensitive methods also detect non‐cancer‐related infections. Here the authors show by RNA sequencing and PCR amplification that a microRNA (BART13‐3p) encoded by the Epstein–Barr Virus (EBV) is associated with circulating vesicles in patients with nasopharyngeal carcinoma, thus distinguishing between cancer and non‐cancer‐related EBV infections.

Relationship between pretreatment concentration of plasma Epstein-Barr virus DNA and tumor burden in nasopharyngeal carcinoma: An updated interpretation

Background

Pretreatment plasma Epstein‐Barr virus (EBV) DNA is an important tumor marker and prognostic factor in nasopharyngeal carcinoma (NPC). This study aimed to clarify the relationship between plasma EBV DNA level and tumor burden.

Materials and Methods

Pretreatment tumor burden was measured by radiologically delineated volumes, including nasopharynx tumor volume (GTVnx) and malignant nodes volume (GTVnd); pretreatment level of plasma EBV DNA was quantified by quantitative polymerase chain reaction. The relationship between natural logarithm of EBV DNA (ln‐DNA) and square root of tumor volume (sq‐GTV) was analyzed by Pearson correlation coefficient and partial correlation coefficient. Correlations in subgroups of tumor and nodal stages were also analyzed. A linear regression model was constructed to evaluate the contribution of tumor volumes to plasma EBV DNA. The prognostic effects of EBV DNA independent of tumor burden were evaluated.

Results

Two thousand two hundred and forty nine nonmetastatic NPC patients with detectable plasma EBV DNA were included in correlation analyses. Ln‐DNA showed significant correlation with sq‐GTVnx (r = 0.171) and sq‐GTVnd (r = 0.339) separately. Together, sq‐GTVnx and sq‐GTVnd could only explain 12.9% of the ln‐DNA. Tumor and nodal stages of disease could clearly influence the strength of relationship in subgroup analysis. After excluding confounding volume information, EBV DNA still can predict death and distant metastasis, but not locoregional relapse.

Conclusion

This study suggests that plasma EBV DNA is not only an index of tumor burden, but may also reflect other tumor features, such as accessibility to circulation, angiogenesis, tumor cell kinetics, metabolic activity, and metastatic potential, among others.

EPSTEIN-BARR VIRUS AND NASOPHARYNGEAL CARCINOMA: VIRAL MARKERS FOR DIAGNOSTICS AND ASSESSMENT OF CLINICAL STATUS OF PATIENTS

The etiological role of the Epstein-Barr virus (EBV) in the development of an undifferentiated histological variant of nasopharyngeal carcinoma (uNPC) found for the first time in regions with a high incidence of this pathology, the Southern provinces of China and the countries of Southeast Asia, and later in the rest of the world, has served as a basis for the widespread use of EBV serological markers for the diagnosis of this form of tumor. In recent years, the use of a test based on the quantitative determination of the EBV DNA concentration in the blood plasma of uNPC patients for early detection and monitoring of the disease has become widespread in endemic regions. In non-endemic regions, such studies virtually have not been carried out, and moreover, the comparative evaluation of the significance of two viral markers, serological and EBV DNA load in the bloodstream of uNPC patients, for diagnostics and evaluation of the therapeutic effect was not investigated. The aim of this study was to compare the clinical value of two serological markers and plasma EBV DNA load in uNPC patients from non-endemic region (Russia). The obtained results indicate that IgA antibodies to the viral capsid antigen (IgA/VCA) and plasma EBV DNA concentration can be successfully used for the diagnosis of uNPC, while IgG/VCA antibodies have no practical significance as an uNPC marker. In addition, it was found that plasma EBV DNA load is more sensitive marker of uNPC than IgA/VCA titers because DNA copy numbers reflect more accurately the effect of the therapy and the clinical state of patients at the stages of remission or relapse. It was shown for the first time that in the non-endemic region the simultaneous evaluation of IgA/VCA antibody levels and the plasma EBV DNA loads are the most effective markers for the diagnostics of uNPC. However, we believe, that it is more practical to use IgA/VCA antibody levels for uNPC screening, and plasma EBV DNA copies - for monitoring of the disease.

Survival analysis of patients with advanced-stage nasopharyngeal carcinoma according to the Epstein-Barr virus status

Purpose

The main aim of this study is to analyze the prognostic differences in nasopharyngeal carcinoma (NPC) patients who are positive and negative for Epstein-Barr virus (EBV).

Results

Of the 1106 patients, 248 (22.4%) had undetectable pre-treatment plasma EBV DNA levels. The total distant metastasis rate for EBV-negative group vs. EBV-positive group were 3.6% (9/248) vs. 15.0% (128/858) (P < 0.001). The estimated 4-year disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRRFS) for EBV-negative group vs. EBV-positive group were 88.9% vs. 76.9% (P < 0.001), 93.6% vs. 85.9% (P = 0.001), 96.7% vs. 84.8% (P < 0.001) and 94.1% vs. 90.0% (P = 0.1), respectively. Multivariate analysis revealed that the EBV status was an independent prognostic factor for DFS (HR, 1.813; 95% CI, 1.219-2.695; P = 0.003), OS (HR, 1.828; 95% CI, 1.075-3.107; P = 0.026) and DMFS (HR, 3.678; 95% CI, 1.859-7.277; P <0.001), and overall stage still remained the most important prognostic factor in patients with stage III-IVB NPC.

Methods and Materials

Data on 1106 patients with non-metastatic, histologically proven advanced-stage (III-IVB) NPC who underwent intensity-modulated radiotherapy (IMRT) were retrospectively reviewed. Patient survival between different EBV status groups were compared.

Conclusions

EBV status was an independent prognostic factor for patients with stage III–IVB NPC. Neoadjuvant chemotherapy (NCT) plus concurrent chemoradiotherapy (CCRT) should be better treatment regimen for EBV-positive patients since distant metastasis was the main failure pattern, and CCRT may be enough for EBV-negative patients.

Prognostic value of plasma Epstein-Barr virus DNA level during posttreatment follow-up in the patients with nasopharyngeal carcinoma having undergone intensity-modulated radiotherapy

Background

The value of Epstein–Barr virus (EBV) DNA assay during posttreatment follow-up of the patients with nasopharyngeal carcinoma (NPC) presenting with different pretreatment plasma EBV DNA levels remains unclear. In the present study, we aimed to evaluate the prognostic value of plasma EBV DNA assay during posttreatment follow-up in the patients with NPC who have undergone intensity-modulated radiotherapy.

Methods

The medical records of 385 NPC patients treated with intensity-modulated radiotherapy between November 2009 and February 2012 were reviewed. All patients underwent plasma EBV DNA assays before treatment, within 3 months after treatment, and then every 3–12 months during posttreatment follow-up period. The recurrence rates for patients with different pretreatment and posttreatment follow-up plasma EBV DNA levels were analyzed.

Results

Of the 385 patients, 267 (69.4%) had detectable pretreatment plasma EBV DNA (> 0 copy/mL) and 93 (24.2%) had detectable posttreatment EBV DNA during a median follow-up of 52.8 months (range 9.3–73.8 months). Detectable EBV DNA during posttreatment follow-up was found in 14.4% (17/118) and 28.5% (76/267) of patients with undetectable and detectable pretreatment EBV DNA, respectively, and was significantly associated with tumor recurrence in both patient groups. EBV DNA was detectable in 12.8% (40/313) of patients who remained disease-free, 56.4% (22/39) of patients with locoregional recurrence alone, and 93.9% (31/33) of patients with distant metastasis as the first recurrence event (P < 0.001); 6.5% (19/292) of patients with undetectable EBV DNA and 57.0% (53/93) of patient with detectable EBV DNA during posttreatment follow-up experienced tumor recurrence. Compared with other cut-off values, the cut-off value of 0 copy/mL for EBV DNA during posttreatment follow-up had the highest area under the ROC curve (AUC) value (0.804, 95% confidence interval 0.741–0.868) for predicting tumor recurrence (sensitivity, specificity, and accuracy: 73.6%, 87.2%, and 84.7%, respectively).

Conclusion

Plasma EBV DNA level during posttreatment follow-up is a good marker for predicting distant metastasis but not locoregional recurrence in the patients with NPC irrespective of the pretreatment EBV DNA levels.

Multiparametric Detection of Antibodies against Different EBV Antigens to Predict Risk for Nasopharyngeal Carcinoma in a High-Risk Population of China

In this study, we aimed to use the combined detection of multiple antibodies against Epstein-Barr virus (EBV) antigens to develop a model for screening and diagnosis of nasopharyngeal carcinoma (NPC). Samples of 300 nasopharyngeal carcinoma patients and 494 controls, including 294 healthy subjects (HC), 99 non-nasopharyngeal carcinoma cancer patients (NNPC), and 101 patients with benign nasopharyngeal lesions (BNL), were incubated with the EUROLINE Anti-EBV Profile 2, and band intensities were used to establish a risk prediction model. The nasopharyngeal carcinoma risk probability analysis based on the panel of VCAgp125 IgA, EBNA-1 IgA, EA-D IgA, EBNA-1 IgG, EAD IgG, and VCAp19 IgG displayed the best performance. When using 26.1% as the cutoff point in ROC analysis, the AUC value and sensitivity/specificity were 0.951 and 90.7%/86.2%, respectively, in nasopharyngeal carcinoma and all controls. In nasopharyngeal carcinoma and controls without the non-nasopharyngeal carcinoma and BNL groups, the AUC value and sensitivity/specificity were 0.957 and 90.7%/88.1%, respectively. The diagnostic specificity and sensitivity of the EUROLINE Anti-EBV Profile 2 assay for both nasopharyngeal carcinoma and early-stage nasopharyngeal carcinoma were higher than that of mono-antibody detection by immune-enzymatic assay and real-time PCR (EBV DNA). In the VCA-IgA-negative group, 82.6% of nasopharyngeal carcinoma patients showed high probability for nasopharyngeal carcinoma, and the negative predictive value was 97.1%. In the VCA-IgA-positive group, 73.3% of healthy subjects showed low probability. The positive predictive value reached 98.2% in this group. The nasopharyngeal carcinoma risk probability value determined by the EUROLINE Anti-EBV Profile 2 might be a suitable tool for nasopharyngeal carcinoma screening. Cancer Prev Res; 10(9); 542-50. ©2017 AACR.

Epstein-Barr virus biomarkers for nasopharyngeal carcinoma in non-endemic regions

The Epstein-Barr virus (EBV) plays a key role in the development of undifferentiated nasopharyngeal carcinoma (uNPC). In uNPC endemic regions EBV-specific antibodies and plasma EBV DNA load are used as markers for the early detection of uNPC and monitoring of the disease. In non-endemic regions, such studies were practically not conducted. The aim of this study was to compare the clinical significance of EBV serological markers and plasma EBV DNA levels for uNPC patients in a non-endemic region, Russia. The results obtained indicate that both viral capsid antigen/immunoglobulin A (VCA/IgA) antibodies and plasma EBV DNA copies can effectively be used for nasopharyngeal carcinoma (NPC) diagnosis. Besides, plasma EBV DNA load was found to be a more sensitive marker of uNPC than VCA/IgA antibody titres, as it reflected the effect of the therapy in stages of remission and relapse of the disease more precisely. Our study, for the first time, demonstrates that the simultaneous use of plasma EBV DNA loads and VCA/IgA antibody levels are indispensable markers for uNPC in non-endemic regions: a serological marker can be more effectively used for NPC screening, but EBV DNA copies are better for monitoring the disease. However, both markers turned out to be practically unsuitable for assessing the clinical status of patients. Serological markers did not correlate with any signs of the tumour process estimated by tumour, node and metastasis (TNM) classification and the plasma EBV DNA loads correlated only with the size of the pathologically altered lymph nodes (N). Additional study is required to confirm these findings.

Investigation on the association between thyroid tumorigeneses and herpesviruses

Herpesviruses have been associated with various human malignancies and with thyroid autoimmunity. Aiming to investigate the presence of these viruses in thyroid nodules, we analyzed serum and thyroid tissue from 183 patients (83 benign and 100 malignant thyroid nodules). We also obtained 104 normal thyroid tissues extracted from the contralateral lobe of these patients. We used ELISA to screen the serology of all patients and a real-time quantitative PCR to analyze thyroid tissue viral load in antibody-positive patients. In addition, the presence of herpesviruses was tested by histological analysis in 20 EBV-positive tissues using the expression of LMP-1 by immunohistochemistry (IHC) and EBER by in situ hybridization (ISH). There was no evidence of HSV-2 or CMV DNA, but we found EBV DNA sequences in 29 (16%) thyroid tissue samples. We also found 7 positive EBV cases out of 104 normal tissues. Viral load was higher in tumors than in their respective normal tissues (p = 0.0002). ISH analysis revealed EBER expression in 11 out of 20 (52%) EBV-positive tissues, mostly in malignant cases (8/11, 73%). The presence of high EBV copy numbers in thyroid tumors and the expression of EBER only in malignant cases suggest an association between EBV and thyroid malignancies. However, we did not find any association between the presence of EBV and/or its viral load and any clinical or pathological tumor feature. Further studies aiming to clarify the mechanisms of EBV infection in thyroid cells are necessary to support a possible role in the development of thyroid cancer.

Plasma Epstein-Barr virus immunoglobulin A and DNA for nasopharyngeal carcinoma screening in the United States

Objective

To examine the Epstein-Barr virus (EBV) IgA and DNA assays as a screening tool for nasopharyngeal carcinoma (NPC) in a nonendemic US population.

Study Design and Setting

Prospective study performed at a teaching hospital in New York City. There were two groups of 155 patients: new NPC patients and controls. An otolaryngologic examination and serial blood testing for serologic markers were performed.

Results

Sensitivity and specificity of EBV IgA and DNA assays were determined. Screening scenarios involving series and parallel testing were evaluated to determine economic feasibility. Series testing provided a sensitivity, specificity, and positive and negative predictive values of 90.6, 93.5, 78.4, and 97.5 percent, respectively. Parallel testing increased the sensitivity to 100 percent.

Conclusion

NPC screening in a high-risk, nonendemic population using EBV-specific serologic markers is effective. Series testing is a statistically sound and economically feasible strategy.

Significance

The development of a cost-effective NPC screening strategy in a high-risk, nonendemic population in the United States. © 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Prognostic Impact of Plasma Epstein-Barr Virus DNA in Patients with Nasopharyngeal Carcinoma Treated using Intensity-Modulated Radiation Therapy

The prognostic value of plasma Epstein-Barr virus (EBV) DNA remains unknown in nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). We retrospectively reviewed medical records of 584 newly diagnosed patients with nonmetastatic and biopsy-proven NPC treated using IMRT. Plasma EBV DNA concentration was measured before therapy (pre-DNA) and within 1 month of completing therapy (post-DNA) using real-time quantitative polymerase chain reaction. Receiver operating characteristic (ROC) curves were generated to identify pre-DNA and post-DNA cut-off values. Prognostic value was assessed using a multivariate Cox proportional hazards model .Three-year disease-free survival (DFS), overall survival (OS), loco-regional relapse-free survival (LRRFS) and distant metastasis-free (DMFS) for pre-DNA >2010 vs.≤2010 were 78.1% vs. 93.6% (P < 0.001), 92.3% vs. 98.9% (P < 0.001), 90.9% vs. 96.6% (P = 0.004) and 85.5% vs. 96.6% (P < 0.001), respectively. Three-year DFS, OS, LRRFS and DMFS for post-DNA >0 vs. = 0 were 49.9% vs. 88.5% (P < 0.001), 72.1% vs. 97.5% (P < 0.001), 86.6% vs. 94.3% (P = 0.019), and 60.5% vs. 93.3% (P < 0.001), respectively. Plasma EBV DNA remains a prognostic factor in IMRT era and should be incorporated into TNM staging to guide individualized treatment strategies in NPC.

Epstein-Barr virus infection and nasopharyngeal carcinoma: the other side of the coin

Oncogenic viruses may have a significant impact on the therapeutic management of several malignancies besides their well-known role in tumor pathogenesis. Epstein-Barr virus (EBV) induces neoplastic transformation of epithelial cells of the nasopharynx by various molecular mechanisms mostly involving activation of oncogenes and inactivation of tumor-suppressor genes. EBV infection can also induce the expression of several immunogenic peptides on the plasma membrane of the infected cells. Importantly, these virus-related antigens may be used as targets for antitumor immunotherapy-based treatment strategies. Two different immunotherapy strategies, namely adoptive and active immunotherapy, have been developed and strongly improved in the recent years. Furthermore, EBV infection may influence the use of targeted therapies for nasopharyngeal carcinoma (NPC) considering that the presence of EBV can induce important modifications in cell signaling. As an example, latent membrane protein type 1 is a viral transmembrane protein mainly involved in the cancerogenesis process, which can also mediate overexpression of the epidermal growth factor receptor (EGFR) in NPC cells, rendering them more sensitive to anti-EGFR therapy. Finally, EBV may induce epigenetic changes in the infected cells, such as DNA hypermethylation and histone deacetylation, that can sustain tumor growth and can thus be considered potential targets for novel therapies. In conclusion, EBV infection can modify important biological features of NPC cells, rendering them more vulnerable to both immunotherapy and targeted therapy.

Levels of plasma Epstein-Barr virus DNA prior and subsequent to treatment predicts the prognosis of nasopharyngeal carcinoma

The level of Epstein-Barr virus DNA (EBV-DNA) in the plasma prior and subsequent to treatment is a reliable biomarker for the screening, diagnosis, monitoring and prognosis of nasopharyngeal carcinoma (NPC). The present retrospective study aimed to determine whether pre- and post-treatment levels of plasma EBV-DNA were predictive of survival in a large sample of patients with NPC. The level of plasma EBV-DNA in 637 NPC patients prior and subsequent to treatment was determined by quantitative polymerase chain reaction. The value of pre- and post-treatment plasma EBV-DNA in predicting the survival of NPC patients was then analyzed. The results revealed that pre-treatment plasma EBV-DNA loads were significantly higher in patients with NPC than those in healthy controls (P<0.001). The percentage of patients with positive plasma EBV-DNA was markedly higher prior to treatment (70.64%; median, 1150 copies/ml; range, 0-9.75×10⁶ copies/ml) than following treatment (25.99%; median, 0 copies/ml; range, 0-3.83×10⁶ copies/ml) (P<0.001). Patients with a high plasma EBV-DNA load presented with a higher clinical tumor classification, lymph node status, metastatic status and overall cancer stage. The risk of NPC relapse and mortality was higher in patients with pre-treatment plasma EBV-DNA levels of ≥1,500 copies/ml than that in patients with <1,500 copies/ml. Furthermore, the risk of relapse and mortality was higher in patients with positive post-treatment plasma EBV-DNA than in patients with negative post-treatment plasma EBV-DNA. Detectable post-treatment plasma EBV-DNA was the most significant prognostic factor to affect relapse-free survival, whilst metastasis was the prognostic factor with the greatest effect on overall survival. These data indicated that pre- and post-treatment levels of plasma EBV-DNA were able to predict the prognosis of NPC. This finding may provide novel references for research and clinical practice.

ABO blood group, Epstein-Barr virus infection and prognosis of patients with non-metastatic nasopharyngeal carcinoma

BACKGROUND

A prior study showed blood type A/AB to be associated with an increased risk of nasopharyngeal carcinoma (NPC) compared to subjects with blood type O. However, the relationship between ABO blood groups and prognosis of NPC patients is still questionable. In addition, whether Epstein-Barr virus (EBV) infection is associated with prognosis of NPC patients with different ABO blood groups is unclear.

MATERIALS AND METHODS

We conducted univariate and multivariable Cox regression analyses based on a consecutive cohort of 1,601 patients to investigate the above issues.

RESULTS

There was no significant difference in overall survival (OS) between different ABO blood groups (p=0.629), neither between A vs. non-A blood groups (p=0.895) nor AB vs. non-AB blood group (p=0.309) in univariate analyses and after adjusting for other factors. Interaction tests revealed that high immunoglobulin A against Epstein-Barr virus viral capsid antigen (VcA-IgA) level was associated with a favorable prognosis in male patients with UICC stage II disease who had an A blood type (p=0.008), compared with those with non-A blood type. In addition, male patients with an A blood group with a high blood lymphocyte level showed a tendency towards better survival in UICC stage III (p=0.096).

CONCLUSIONS

ABO blood group status is not associated with the prognosis of patients with NPC. Additionally, blood group A male NPC patients with high VcA-IgA level or high blood lymphocyte counts might be correlated with a favorable prognosis in UICC stage II or III, respectively.

The Biology and Clinical Utility of EBV Monitoring in Blood

Epstein-Barr virus (EBV) DNA in blood can be quantified in peripheral blood mononuclear cells, in circulating cell-free (CCF) DNA specimens, or in whole blood. CCF viral DNA may be actively released or extruded from viable cells, packaged in virions or passively shed from cells during apoptosis or necrosis. In infectious mononucleosis, viral DNA is detected in each of these kinds of specimens, although it is only transiently detected in CCF specimens. In nasopharyngeal carcinoma, CCF EBV DNA is an established tumor marker. In EBV-associated Hodgkin lymphoma and in EBV-associated extranodal NK-/T-cell lymphoma, there is growing evidence for the utility of CCF DNA as a tumor marker.

Positivity of both plasma Epstein-Barr virus DNA and serum Epstein-Barr virus capsid specific immunoglobulin A is a better prognostic biomarker for nasopharyngeal carcinoma

Background

Positivity of plasma Epstein–Barr virus (EBV)-DNA or serum virus capsid antigen-specific IgA (VCA-IgA) is a biomarker for the prognosis of nasopharyngeal carcinoma (NPC). The objective of this study was to determine the value of positivity for plasma EBV-DNA and/or VCA-IgA in predicting the survival of patients with NPC.

Methods

Plasma EBV-DNA and serum VCA-IgA in 506 NPC patients in this retrospective study were detected by quantitative real time polymerase chain reaction and enzyme-linked immunoabsorbent assay, respectively. The value of positivity for EBV-DNA and/or VCA-IgA in predicting the survival of patients with NPC was analyzed.

Results

Patients with positivity for both EBV-DNA and VCA-IgA had significantly shorter periods of relapse free survival (RFS) and overall survival (OS) than those with positive single measure or negative for both measures, and patients with positive single measure had significantly shorter periods of RFS and OS than those with negative for both. Multivariate analysis indicated that the positivity for EBV-DNA and/or VCA-IgA were significant risk factors for shorter periods of RFS and OS.

Conclusion

These data indicated that positivity for both EBV-DNA and VCA-IgA was a better biomarker for the prognosis of patients with NPC. Our findings may provide new references for clinical practice.

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We analyzed the positivity for EBV-DNA and/or VCA-IgA in predicting NPC survival.

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Patients with both EBV-DNA(+) and VCA-IgA(+) had significantly shorter RFS and OS.

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EBV-DNA and/or VCA-IgA were significant risk factors for NPC survival.

A meta-analysis on the EBV DNA and VCA-IgA in diagnosis of Nasopharyngeal Carcinoma

OBJECTIVE

We conducted a meta-analysis to compare the EBV DNA and VCA-IgA in diagnosis of Nasopharyngeal Carcinoma, and provide important evidence for screening method of NPC.

METHODOLOGY

Three databases, Medline (from Jan. 1966 to Jan. 2012), EMBASE (from January 1988 to Jan. 2012) and Chinese Biomedical Database (from January 1980 to Jan. 2012) were used to detect the role of EBV DNA and VCA-IgA in diagnosis of NPC. Meta-DiSc statistical software was used for analysis.

RESULTS

Twenty seven case-control and cohort studies were included in final analysis. A total of 1554 cases and 2932 controls were included in our meta-analysis. The Sensitivity specificity, positive likelihood (+LR) and likelihood negative (-LR) of EBV-DNA in diagnosis of NPC were 0.75(0.72-0.76), 0.87(0.85-0.88), 6.98(4.50-10.83) and 0.18(0.11-0.29), respectively, and they were 0.83(0.81-0.85), 0.85(0.83-0.86), 10.89(5.41-21.93) and 0.20(0.14-0.29) for VCA-IgA. The SROC for EBV DNA detection was 0.939, while this was 0.936 for VCA-IgA detection. The subgroup analysis showed EBV-DNA had larger areas under the summary receiver operator curve when compared with VCA-IgA in high quality and low quality studies.

CONCLUSION

Our meta-analysis indicated the EBV DNA had higher sensitivity and specificity in diagnosis of NPC.

Clinical value of serum Epstein-Barr virus DNA assay in the diagnosis of nasopharyngeal carcinoma

Serum Epstein-Barr virus DNA has been approved for diagnosing nasopharyngeal carcinoma (NPC). The goal of this meta-analysis was to evaluate the clinical value of the serum Epstein-Barr virus DNA in the diagnosis of NPC. The PubMed, Embase, Web of Knowledge, Chinese Wanfang Med Online, and National Knowledge Infrastructure (CNKI) databases were searched to identify suitable studies. The pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) of the serum Epstein-Barr virus DNA for the diagnosis of NPC were calculated. Summary receiver operating characteristic curves were used to summarize overall test performances. Meta-Disc 1.4 and Stata 12.0 softwares were used to analyze the data. A total of 2,520 patients from ten trials were subjected to meta-analysis. The summary estimates of the serum Epstein-Barr virus DNA for NPC diagnosis were as follows: sensitivity 0.69 (95 % confidence interval (CI) 0.65-0.72), specificity 0.84 (95 % CI = 0.82-0.86), LR + 4.81 (95 % CI = 2.94-7.88), LR - 0.25 (95 % CI = 0.13-0.48), DOR 24.65 (95 % CI = 12.64-48.07), and area under the summary receiver operator characteristic (SROC) curve (AUC) was 0.8979. Our study demonstrates that the serum Epstein-Barr virus DNA could be a useful tumor marker for NPC diagnosis.

Application of circulating plasma/serum EBV DNA in the clinical management of nasopharyngeal carcinoma

Elevated levels of circulating cell-free Epstein-Barr virus (EBV) DNA have been detected in plasma and serum samples from nasopharyngeal cancer (NPC) patients by quantitative real time PCR (qPCR) test. This qPCR test for circulating EBV DNA was found to be useful in the clinical management of NPC patients. For instance, EBV DNA qPCR test has good sensitivity and specificity in the detection of NPC at disease onset. Increase of the viral DNA load was found in NPC patients at late stages of disease. High EBV DNA load at disease onset or detectable viral load post-treatment was associated with poor survival or frequent relapse in NPC patients. Residual EBV DNA load after primary treatment could be a useful indicator to justify adjuvant chemotherapy. The qPCR test might also be applied to define a poor prognostic group in patients at early stage (I/II) for implementing concurrent chemo-radiotherapy (chemo-RT) to improve patients' outcome. The test is also useful to monitor distant metastases or response to radiotherapy, chemo-RT or surgery. Supplementary tests, however, are needed to pick up EBV negative WHO type I NPC and test improvement is needed to increase sensitivity in detecting stage I disease and local recurrence.

Comparison of two laboratory extraction techniques for the detection of Epstein-Barr virus in the saliva of nasopharyngeal carcinoma patients

AIM

The aim of the present study was to compare the effectiveness of DNA extraction using an extraction kit against the standard boiling technique for the detection of Epstein-Barr virus (EBV) DNA in nasopharyngeal carcinoma (NPC) patients.

METHODS

Stimulated whole saliva samples from newly-diagnosed NPC patients were collected. EBV DNA was extracted by both techniques (n = 23) followed by quantitative real-time polymerase chain reaction (PCR) using the primer/probe set for BALF5.

RESULTS

The results of the quantitative real-time PCR were reproducible in both groups. The two techniques were moderately correlated (r = 0.67, P < 0.05), and the degree of agreement was good. However, the mean EBV DNA level in the boiling group (3.02 ± 8.67 × 10(6) copies/μL) was significantly higher than the extraction kit group (1.15 ± 2.66 × 10(6) copies/μL) (P < 0.05). The EBV DNA level was higher in patients at an advanced overall stage (P = 0.05).

CONCLUSION

The results of the present study showed that the performance of the extraction kit was not superior to the simple boiling technique for the detection of salivary EBV DNA in NPC patients using real-time PCR. The salivary EBV DNA level in patients at an advanced overall stage appeared to be higher than in patients at an early stage.

Quantification of Epstein-Barr virus DNA in patients with idiopathic orbital inflammatory pseudotumor

Inflammatory pseudotumors (IPT) are soft tissue tumors that include a diverse group of lesions characterized by inflammatory cell infiltration and variable fibrotic responses. Idiopathic orbital inflammatory pseudotumors (IOIP) are IPTs of unknown etiology that develop in the orbit. Due to the lack of well-defined pathogenic mechanisms, diagnosis and treatment of this disease remain a significant challenge. Epstein-Barr virus (EBV) infection, which causes significant lymphocyte infiltration, has been proposed to be involved in IOIP. This study tries to validate the relationship between EBV infection and the development of IOIP. Sixteen IOIP tissue samples were obtained from patients during surgical resection of the lesion. One Graves' ophthalmopathy tissue sample and 20 normal donors' plasma serves as controls. The plasma level of five EBV antibodies, including VCA-IgG, VCA-IgA, VCA-IgM, EA-IgG and EBNA1-IgG were examined. All plasma samples were EB-VCA-IgG positive and EB-VCA-IgM negative, suggesting that all people tested had been infected with EBV but not in the acute infection stage. EBV-DNA was detected in 15/16 (94%) of IOIP tissue samples despite different levels of lymphocyte infiltration and 5/16 plasma samples (31%) were detected EBV DNA positive which is higher than the normal controls (10%). Percent of positive plus suspected positive samples with one or more of the three important risk markers (VCA-IgA, EA-IgG, EBV-DNA) is 50% of the patients (8/16) which is much higher compare with the normal controls (20%). The results further reveal the relationship between IOIP and EBV infection.

Phase I clinical trial of valacyclovir and standard of care cyclophosphamide in children with endemic Burkitt lymphoma in Malawi

Treatment options for Epstein-Barr virus (EBV)-associated Burkitt lymphoma in Africa are limited because of chemotherapy-associated toxicity. Since other EBV-associated diseases respond to antiviral agents, we investigated adding an antiviral agent, valacyclovir, to the current chemotherapy regimen in Malawi. In this phase I safety study, we showed that cyclophosphamide combined with valacyclovir was safe. Phase II efficacy trials should now be undertaken.

BACKGROUND

Nucleoside analogues, including acyclovir, ganciclovir, and their precursors, have shown some efficacy against several Epstein-Barr virus (EBV)-associated diseases, including active EBV infection and posttransplantation lymphoproliferative disorder (PTLD). They have also been proposed as a possible treatment for EBV-associated malignancies, including endemic Burkitt lymphoma. The safety of nucleoside analogues in combination with chemotherapy in the developing world has not been studied and is necessary before any large scale efficacy trials are conducted.

PATIENTS AND METHODS

Children 3-15 years old meeting inclusion criteria were assigned to a 3+3 dose escalation trial of combination valacyclovir (15 and 30 mg/kg, 3 times daily for 40 days) and cyclophosphamide (CPM) (40 mg/kg day 1, 60 mg/kg on days 8, 18, and 28) or CPM monotherapy. Subjects were monitored for clinical and laboratory toxicity and had EBV levels measured regularly. Dose-limiting toxicity (DLT) was our primary outcome.

RESULTS

We found that the combination of valacyclovir and CPM was safe and did not lead to any DLT compared with CPM monotherapy. The most common side effects were vomiting, abdominal pain, and tumor site pain, which were similar in both arms. Patients with measurable serum EBV showed decreased loads over their treatment course.

CONCLUSIONS

We recommend a phase II valacyclovir dose of 30 mg/kg 3 times daily for 40 days. We also observed that 6 of our 12 patients with presumed Burkitt lymphoma had measurable EBV viral loads that decreased over the course of their treatment, suggesting that phase II studies should investigate this correlation further. This study paves the way for a phase II efficacy trial of combined valacyclovir and CPM in the treatment of endemic Burkitt lymphoma.

Current and emerging treatment options for nasopharyngeal carcinoma

In this article, we focus on the current and emerging treatments in nasopharyngeal cancer (NPC). A detailed evolution of the current standard of care, and new techniques and treatment options will be reviewed. Intergroup 0099 established the role for chemoradiotherapy (chemo-RT) in the treatment of nasopharyngeal carcinoma. Multiple randomized Phase III trials have shown the benefit of chemo-RT; however, none of these studies utilized modern radiotherapy (RT) techniques of intensity-modulated radiation therapy (IMRT). IMRT has the ability to deliver high doses of radiation to the target structures while sparing adjacent bystander healthy tissues, and has now become the preferred RT treatment modality. Chemotherapy also has had a shifting paradigm of induction and/or adjuvant chemotherapy combined with RT alone, to the investigation with concurrent chemo-RT. New treatment options including targeted monoclonal antibodies and small molecule tyrosine kinase inhibitors are being studied in NPC. These new biologic therapies have promising in vitro activity for NPC, and emerging clinical studies are beginning to define their role. RT continues to expand its capabilities, and since IMRT and particle therapy, specifically intensity-modulated proton therapy (IMPT), has reports of impressive dosimetric efficacy in-silica. Adaptive RT is attempting to reduce toxicity while maintaining treatment efficacy, and the clinical results are still in their youth. Lastly, Epstein– Barr virus (EBV) DNA has recently been studied for prediction of tumor response and its use as a biomarker is increasingly promising to aid in early detection as well as supplementing the current staging system. RT with or without chemotherapy remains the standard of care for nasopharyngeal carcinoma. Advances in RT technique, timing of chemotherapy, biologically targeted agents, particle therapy, adaptive RT, and the incorporation of EBV DNA as a biomarker may aid in the current and future treatment of nasopharyngeal cancer.

Current management of nasopharyngeal cancer

Management of nasopharyngeal carcinoma is one of the greatest clinical challenges. Appropriate detection is not easy because of its anatomical location; sensitive biomarkers in addition to endoscopic and radiological examinations would be valuable. One useful biomarker (particularly for nonkeratinizing carcinoma) is the plasma level of Epstein-Barr viral deoxyribonucleic acid, and its role as a tool for prognostication and monitoring disease progress is presented. Radiotherapy is the primary treatment modality, and using radiation therapy in combination with chemotherapy is recommended for the treatment of locoregionally advanced tumors. Intensity-modulated radiotherapy techniques with image guidance to ensure setup precision are recommended if resources allow; adaptive replanning should be considered if major deviations from the intended dose distribution occur during the treatment course. Most contemporary series have reported encouraging results, with locoregional control exceeding 90%; the key problem is distant failure. The therapeutic margin is extremely narrow. Although significant reduction of some toxicities (eg, xerostomia) and better quality of life is now achievable especially for early stages, the risk of major late toxicities remains substantial. This review will focus on the primary treatment: the current consensus and controversies in the treatment strategy for different stages, the choice of chemotherapy regimen, and the key factors for improving the therapeutic ratio of radiotherapy will be discussed. Summary of the current achievement and direction for future improvement will be presented.

An epidemiological and molecular study of the relationship between smoking, risk of nasopharyngeal carcinoma, and Epstein-Barr virus activation

BACKGROUND

Elevated levels of antibodies against antigens in the Epstein-Barr virus (EBV) lytic phase are important predictive markers for nasopharyngeal carcinoma (NPC) risk. Several lifestyle factors, including smoking, have also been associated with NPC risk. We hypothesized that some specific lifestyle factors induce transformation of EBV from the latent to the lytic stage and contribute to NPC occurrence.

METHODS

We conducted a case-control study using data from male case patients (n = 1316) and control subjects (n = 1571) living in Guangdong Province, an area in China at high risk for NPC, to study potential NPC risk factors and EBV inducers. Two independent healthy male populations from a second high-risk area (n = 1657) and a low-risk area (n = 1961) were also included in the analysis of potential EBV inducers using logistic regression models. In vitro assays were performed to investigate the effect of cigarette smoke extract on EBV activation in two EBV-positive cell lines. All statistical tests were two-sided.

RESULTS

Smoking was associated with an increased risk of NPC among the Guangdong participants with 20-40 and 40 or more pack-years vs never smokers (OR = 1.52, 95% CI = 1.22 to 1.88 and OR = 1.76, 95% CI = 1.34 to 2.32, respectively; P (trend) < .001). Smoking was the only factor linked to EBV seropositivity among the expanded control group and the independent low-risk population. In vitro experiments showed that cigarette smoke extract promoted EBV replication, induced the expression of the immediate-early transcriptional activators Zta and Rta, and increased transcriptional expression levels of BFRF3 and gp350 in the lytic phase.

CONCLUSION

Smoking is not only associated with NPC risk in individuals from China but is also associated with EBV seropositivity in healthy males and is involved in EBV activation.

Host-tumor interactions in nasopharyngeal carcinomas

Like other human solid tumors, nasopharyngeal carcinoma (NPC) is a tissue and a systemic disease as much as a cell disease. Tumor cell population in NPC is highly heterogeneous. Heavy infiltration by non-malignant leucocytes results at least in part from the production of abundant inflammatory cytokines by the malignant epithelial cells. There is indirect evidence that interactions between stromal and malignant cells contribute to tumor development. Peripheral blood samples collected from NPC patients contain multiple products derived from the tumor, including cytokines, non-cytokine tumor proteins, tumor exosomes and viral nucleic acids. These products represent a potential source of biomarkers for assessment of tumor aggressiveness, indirect exploration of cellular interactions and monitoring of tumor response to therapeutic agents. Most NPC patients are immunocompetent with evidence of active humoral and cellular immune responses against EBV-antigens at the systemic level. Tumor development is facilitated by local immunosuppressive factors which are not fully understood. Local accumulation of regulatory T-cells is probably one important factor. At least two NPC tumor products are suspected to contribute to their expansion, the cytokine CCL20 and the tumor exosomes carrying galectin 9. In the future, new therapeutic modalities will probably aim at breaking immune tolerance or at blocking cellular interactions critical for tumor growth.

Detection of Epstein-Barr virus DNA in serum or plasma for nasopharyngeal cancer: a meta-analysis

BACKGROUND

Studies have shown that the plasma or serum cell-free Epstein-Barr virus (EBV) DNA level might be a tumor marker for the diagnosis of nasopharyngeal carcinoma (NPC).

OBJECTIVE

The objective of this study was to evaluate the diagnostic value of the detection of EBV DNA in plasma or serum for NPC.

METHODS

Articles related to the diagnosis of NPC by the detection of EBV DNA in plasma or serum were retrieved from different databases. Sensitivity, specificity, summary receiver operator curves, and likelihood ratios were pooled to assess the diagnostic value of individual diagnostic tests.

RESULTS

Fifteen studies were included in the meta-analysis. The pooled sensitivity and specificity were 89.1% (95% confidence interval [CI], 87.0%-90.9%) and 85.0% (95% CI, 83.0%-86.9%). The subgroup analysis regarding sample type found that the pooled sensitivity and specificity were 91.4% (95% CI, 89.0%-93.4%) and 93.2% (95% CI, 91.2%-95.0%) for the plasma group and 84.4% (95% CI, 79.9%-88.3%) and 76.0% (95% CI, 72.1%-79.6%) for the serum group.

CONCLUSION

The detection of EBV DNA for the diagnosis of NPC has good sensitivity and specificity and might be helpful for the screening of NPC.

The incidence of Epstein-Barr virus in nasopharyngeal carcinoma of Jordanian patients

Aim of this study was to investigate the incidence of Epstein-Barr virus (EBV) in patients diagnosed with undifferentiated nasopharyngeal carcinoma (UNPC) from the Northern Province of Jordan. All cases diagnosed with UNPC at King Abdullah University Hospital, Irbid, Jordan, between the years 1991 and 2009 inclusive were examined. Clinical data including age, gender, mode of presentation, site of biopsy were retrieved from pathology reports. In situ hybridization for (EBV)--EBERs was performed on cases with available paraffin blocks. Correlation between the different clinical variables and results of in situ hybridization was performed. There were 49 cases diagnosed with UNPC, only 39 specimens were available and studied. The median age of presentation was 41 years (range 9-70 years). Bimodal age distribution was noted, the first peak between 15 and 19 years of age and second between 60 and 64 years of age. Males were slightly more commonly affected than females. Cervical lymph node enlargement was the most common mode of presentation, followed by nasal obstruction. Biopsies were obtained primarily from the posterior nasal space, followed by cervical lymph node. Positive staining for EBERs by in situ hybridization was seen in 92.3% of the cases examined. There was no difference in detection rate between males and females or adults and pediatrics. All cases obtained from posterior nasal space were positive. The three negative cases were from biopsies obtained from cervical lymph nodes, which was statistically significant (P value <0.05). Nasopharyngeal carcinoma in Jordan is seen in both children and adults. It is associated with EBV infection in most, but not all cases. Posterior nasal space shows a more consistent staining for EBERs than cervical lymph nodes. The presence of other association with UNPC including cigarette smoking could possibly explain the cases with negative association.

Using Epstein-Barr viral load assays to diagnose, monitor, and prevent posttransplant lymphoproliferative disorder

Epstein-Barr virus (EBV) DNA measurement is being incorporated into routine medical practice to help diagnose, monitor, and predict posttransplant lymphoproliferative disorder (PTLD) in immunocompromised graft recipients. PTLD is an aggressive neoplasm that almost always harbors EBV DNA within the neoplastic lymphocytes, and it is often fatal if not recognized and treated promptly. Validated protocols, commercial reagents, and automated instruments facilitate implementation of EBV load assays by real-time PCR. When applied to either whole blood or plasma, EBV DNA levels reflect clinical status with respect to EBV-related neoplasia. While many healthy transplant recipients have low viral loads, high EBV loads are strongly associated with current or impending PTLD. Complementary laboratory assays as well as histopathologic examination of lesional tissue help in interpreting modest elevations in viral load. Circulating EBV levels in serial samples reflect changes in tumor burden and represent an effective, noninvasive tool for monitoring the efficacy of therapy. In high-risk patients, serial testing permits early clinical intervention to prevent progression toward frank PTLD. Restoring T cell immunity against EBV is a major strategy for overcoming PTLD, and novel EBV-directed therapies are being explored to thwart virus-driven neoplasia.

Laboratory assays for Epstein-Barr virus-related disease

Epstein-Barr virus (EBV) infects various cell types in a wide spectrum of benign and malignant diseases. Laboratory tests for EBV have improved and are increasingly used in diagnosis, prognosis, prediction, and prevention of diseases ranging from infectious mononucleosis to selected subtypes of lymphoma, sarcoma, and carcinoma. Indeed, the presence of EBV is among the most effective tumor markers supporting clinical management of cancer patients. In biopsies, localization of EBER transcripts by in situ hybridization remains the gold standard for identifying latent infection. Other RNA- and protein-based assays detect lytic viral replication and can distinguish carcinoma-derived from lymphocyte-derived EBV in saliva or nasopharyngeal brushings. Analysis of blood using EBV viral load and serology reflects disease status and risk of progression. This review summarizes prior research in the context of basic virologic principles to provide a rational strategy for applying and interpreting EBV tests in various clinical settings. Such assays have been incorporated into standard clinical practice in selected settings such as diagnosis of primary infection and management of patients with immune dysfunction or nasopharyngeal carcinoma. As novel therapies are developed that target virus-infected cells or overcome the adverse effects of infection, laboratory testing becomes even more critical for determining when intervention is appropriate and the extent to which it has succeeded.

Evaluation of the Epstein-Barr virus R-gene quantification kit in whole blood with different extraction methods and PCR platforms

Reliable real-time quantitative PCR assays to measure Epstein-Barr virus (EBV) DNA load (EBV) are useful for monitoring EBV-associated diseases. We evaluated a new commercial kit, EBV R-gene Quantification kit (Argene, Varilhes, France) to quantify EBV DNA load in whole blood. Assay performance was assessed with two PCR platforms (LightCycler 2.0 and SmartCycler 2.0) and three commercial DNA extraction methods. The assay was compared with our in-house real-time EBV PCR using samples from the Quality Control for Molecular Diagnostics 2006 EBV proficiency program and using 167 whole-blood specimens from individuals with infectious mononucleosis, from transplanted or HIV-infected patients, and from EBV-seropositive healthy carriers. The EBV R-gene assay was sensitive to 500 copies of EBV DNA per milliliter of whole blood with the two PCR platforms and the three extraction methods and was linear across 4 orders of magnitude. Intra- and interassay coefficients of variations were less than 20%. Nine of 10 samples tested with the EBV R-gene were in agreement with the expected qualitative results of the Quality Control for Molecular Diagnostics 2006 EBV proficiency program, and 7 of 10 samples were within +/-0.5 log units of the expected quantitative values, with discrepant results mostly observed for low viral load (ie, <1000 copies/ml). In the clinical specimens, the correlation between the R-gene assay and the in-house PCR was high (r=0.92). In conclusion, the EBV R-gene assay accurately assesses the EBV DNA load in whole blood of patients with various forms of EBV infections.

Evaluation of Epstein-Barr virus antigen-based immunoassays for serological diagnosis of nasopharyngeal carcinoma

BACKGROUND

Immunofluorescence (IF) assays based on Epstein-Barr virus (EBV)-encoded antigens have traditionally been the preferred approach for serological screening of nasopharyngeal carcinoma (NPC).

OBJECTIVES

To compare the performance of two new commercial assays (indicated by COMM) using, respectively, the IF and enzyme-linked immunosorbent assay (ELISA) formats with an in-house IF assay (IFA).

STUDY DESIGN

Sera from 163 patients with histologically confirmed NPC, and 98 healthy controls were tested with each of these assays and their results compared.

RESULTS

The sensitivity, specificity, positive and negative predictive values, respectively, for the COMM VCA IgA ELISA were 92.6%, 94.9%, 96.8%, 88.6%; for the COMM VCA IgA IFA were 96.9%, 41.8%, 73.5%, 89.1%; for the in-house VCA IgA IFA were 98.2%, 72.4%, 85.6%, 95.9%; for the COMM EA IgA ELISA were 46.6%, 100%, 100%, 53.0%; for the COMM EA IgA IFA were 77.3%, 100%, 100%, 72.6%; and for the in-house EA IgA IFA were 77.9%, 99.0%, 99.2%, 72.9%.

CONCLUSIONS

The receiver operating characteristic curves comparison showed a marginal superior accuracy for the COMM VCA IgA ELISA, suggesting this to be used as a high-throughput serological screening assay, with the more specific COMM EA IgA IFA as a follow-up confirmatory assay in this NPC-endemic area.