Plasma Epstein-Barr virus DNA screening followed by ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography in detecting posttreatment failures of nasopharyngeal carcinoma

The role of 18 F-FDG PET/CT in detecting recurrence and metastasis in posttreatment nasopharyngeal carcinoma patients with elevated Epstein-Barr virus DNA

OBJECTIVE

The objective of this study is to evaluate and compare the clinical utility of 18 F-fluoro-2-deoxy-d-glucose PET and computed tomography ( 18 F-FDG PET/CT) in detecting recurrence and metastasis in patients with nasopharyngeal carcinoma (NPC) who exhibit elevated levels of Epstein-Barr virus (EBV) DNA following treatment.

METHODS

A total of 103 patients with NPC were studied retrospectively. All patients were in remission following initial treatment. Elevated EBV DNA was found for the first time at review and 18 F-FDG PET/CT imaging was completed. The number of tracer lesions and the maximum standardized uptake value in the body region were recorded to evaluate the diagnostic ability of 18 F-FDG PET/CT. The final diagnosis was confirmed either through pathology or clinical follow-up lasting 6 months or longer.

RESULTS

Out of the 103 patients, 97 patients had a total of 434 lesions that were ultimately diagnosed as recurrent or metastatic. In patient-based analyses, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 18 F-FDG PET/CT imaging were 100%, 50%, 97%, and 100%, respectively. In lesion-based analyses, the sensitivity, specificity, PPV, and NPV of 18 F-FDG PET/CT imaging were 99.3%, 30.3%, 94.9%, and 83.3%, respectively.

CONCLUSION

18 F-FDG PET/CT demonstrates potential value in detecting recurrence and metastasis of NPC.

Patterns of failure and prognosis in nasopharyngeal carcinoma according to Epstein-Barr virus DNA status

PURPOSE

To investigate the patterns of failure and prognosis in recurrent or metastatic nasopharyngeal carcinoma (rmNPC) according to Epstein-Barr virus-DNA (EBV-DNA) status.

METHODS

We included NPC patients who were diagnosed with locoregional recurrence (LRR) and/(or) distant metastasis (DM) between January 2017 and June 2024. Receiver operating characteristic analysis, Chi-square test, Wilcoxon rank sum test, Kaplan-Meier method, and Multivariate Cox regression analyses were used for statistical analysis.

RESULTS

This study involved 108 patients, including 105 (97.2%) who had EBV-DNA detectable at the initial diagnosis of NPC. Regarding progression patterns, 34 patients (31.5%) experienced only LRR, while 60 patients (55.6%) had only DM. LRR followed by DM was observed in 5 (4.6%) patients, DM followed by LRR occurred in 2 (1.8%) patients, and both LRR and DM were presented simultaneously in 7 (6.5%) patients. EBV-DNA positivity rates significantly differed between LRR and DM patients, at 76.9% and 97.1% respectively (P = 0.003). A significant difference was also observed in EBV-DNA levels, with a median level of 413 copies/mL for LRR and 6,550 copies/mL for DM (P < 0.001). While the EBV-DNA positivity rate did not differ significantly between oligometastatic disease and polymetastatic disease (P = 0.493), the levels were significantly elevated in the polymetastatic disease group than the oligometastatic disease group (P < 0.001). Multivariate analysis showed that liver metastasis (P = 0.012) and EBV-DNA levels ≥ 3,525 copies/mL at progression (P = 0.009) independently correlated with poorer overall survival.

CONCLUSIONS

Our study provides substantial evidence linking higher EBV-DNA levels with disease failure patterns and identifies liver metastasis and EBV-DNA levels at disease progression as independent prognostic factors for poorer overall survival in rmNPC patients.

Liquid biopsy with plasma Epstein-Barr virus DNA characterizes biological relapse for the prediction of cancer recurrence in non-disseminated nasopharyngeal carcinoma

PURPOSE

To investigate whether a bounce in plasma Epstein-Barr virus (EBV) DNA during posttreatment surveillance of nasopharyngeal carcinoma (NPC) informs the risk of clinical recurrence and its implication for early therapeutic intervention.

METHODS

950 non-disseminated NPC patients with completed remission in 3 months after treatment were retrospectively screened. Detectable EBV DNA with no evidence of clinical relapse during follow-up was deemed as DNA bounce. The diagnostic and prognostic performance of EBV DNA bounce was assessed for subsequent failures.

RESULTS

Tumor recurrence occurred in 6.6 %, 10.1 % and 65.8 % in the group with persistently negative EBV DNA, single positive test and ≥ 2 positive tests, respectively. EBV DNA bounce over twice was associated with worse disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) than the other two groups. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the prediction of recurrence were 0.56, 0.95, 0.66, 0.93 and 0.90 using two positive tests, which were hence deemed as biological relapse. Serial cutoffs (EBV DNA 1 ≥ 40 copies/ml or EBV DNA 2 ≥100 copies/ml) further defined a high-risk subgroup with an eventual recurrence rate of 77.9 % and 3-year DFS of merely 20.5 %. Prophylactic medical intervention with capecitabine or S1 significantly improved the 3-year DFS when compared to those with observation.

CONCLUSIONS

The earliest two positive tests of EBV DNA represent a biomarker of biological relapse that allows early detection of clinical recurrence in EBV-related NPC. For high-risk biological relapse, preemptive intervention provides potential survival benefits.

Toripalimab plus capecitabine in the treatment of patients with residual nasopharyngeal carcinoma: a single-arm phase 2 trial

Patients with residual nasopharyngeal carcinoma after receiving definitive treatment have poor prognoses. Although immune checkpoint therapies have achieved breakthroughs for treating recurrent and metastatic nasopharyngeal carcinoma, none of these strategies have been assessed for treating residual nasopharyngeal carcinoma. In this single-arm, phase 2 trial, we aimed to evaluate the antitumor efficacy and safety of toripalimab (anti-PD1 antibody) plus capecitabine in patients with residual nasopharyngeal carcinoma after definitive treatment (ChiCTR1900023710). Primary endpoint of this trial was the objective response rate assessed according to RECIST (version 1.1). Secondary endpoints included complete response rate, disease control rate, duration of response, progression-free survival, safety profile, and treatment compliance. Between June 1, 2020, and May 31, 2021, 23 patients were recruited and received six cycles of toripalimab plus capecitabine every 3 weeks. In efficacy analyses, 13 patients (56.5%) had complete response, and 9 patients (39.1%) had partial response, with an objective response rate of 95.7% (95% CI 78.1-99.9). The trial met its prespecified primary endpoint. In safety analyses, 21 of (91.3%) 23 patients had treatment-related adverse events. The most frequently reported adverse event was hand-foot syndrome (11 patients [47.8%]). The most common grade 3 adverse event was hand-foot syndrome (two patients [8.7%]). No grades 4-5 treatment-related adverse events were recorded. This phase 2 trial shows that combining toripalimab with capecitabine has promising antitumour activity and a manageable safety profile for patients with residual nasopharyngeal carcinoma.

Residual plasma Epstein-Barr virus DNA after intensity-modulated radiation therapy is associated with poor outcomes in nasopharyngeal carcinoma

Aim: To investigate the effects of residual plasma Epstein-Barr virus (EBV) DNA levels after 3 months of intensity-modulated radiation therapy (IMRT) (postIMRT-EBV DNA) on prognosis in patients with nasopharyngeal carcinoma. Methods: Data from 300 patients were retrospectively collected for analysis. Results: Of these patients, 25 (8.3%) and 275 (91.7%) had positive and negative postIMRT-EBV DNA, respectively. Multivariate survival analysis showed that EBV DNA >688 IU/ml was independently associated with inferior distant metastasis-free survival (p = 0.003) and progression-free survival (p = 0.002). Moreover, postIMRT-EBV DNA was independently associated with inferior locoregional recurrence-free survival (hazard ratio: 4.325; p = 0.018), distant metastasis-free survival (hazard ratio: 10.226; p < 0.001) and progression-free survival (hazard ratio: 10.520; p < 0.001). Conclusion: Positive postIMRT-EBV DNA is a prognostic biomarker for nasopharyngeal carcinoma.

Association of delayed chemoradiotherapy with elevated Epstein-Barr virus DNA load and adverse clinical outcome in nasopharyngeal carcinoma treatment during the COVID-19 pandemic: a retrospective study

BACKGROUND

To summarize the impact of radiotherapy (RT) and chemotherapy delays on patients with nasopharyngeal carcinoma (NPC) during the COVID-19 pandemic.

METHODS

We retrospectively included 233 patients with stage II-IVa NPC treated with RT and chemotherapy between December 11, 2019 and March 11, 2020. The outcomes were elevation in the EBV DNA load between two adjacent cycles of chemotherapy or during RT, and 1-year disease-free survival (DFS).

RESULTS

RT delay occurred in 117 (50%) patients, and chemotherapy delay occurred in 220 (94%) patients. RT delay of ≥ 6 days was associated with a higher EBV DNA elevation rate (20.4% vs. 3.6%, odds ratio [OR] = 6.93 [95% CI = 2.49-19.32], P < 0.001), and worse 1-year DFS (91.2% vs. 97.8%, HR = 3.61 [95% CI = 1.37-9.50], P = 0.006), compared with on-schedule RT or delay of < 6 days. Chemotherapy delay of ≥ 10 days was not associated with a higher EBV DNA elevation rate (12.5% vs. 6.8%, OR = 1.94 [95% CI = 0.70-5.40], P = 0.20), or worse 1-year DFS (93.8% vs. 97.1%, HR = 3.73 [95% CI = 0.86-16.14], P = 0.059), compared with delay of < 10 days. Multivariable analyses showed RT delay of ≥ 6 days remained an independent adverse factor for both EBV DNA elevation and DFS.

CONCLUSION

To ensure treatment efficacy for patients with nonmetastatic NPC, initiation of RT should not be delayed by more than 6 days; the effect of chemotherapy delay requires further investigation.

Development and validation of a joint model for dynamic prediction of overall survival in nasopharyngeal carcinoma based on longitudinal post-treatment plasma cell-free Epstein-Barr virus DNA load

OBJECTIVES

To develop and validate a joint model for dynamic prediction of overall survival (OS) in nasopharyngeal carcinoma (NPC) based on longitudinal post-treatment plasma cell-free Epstein-Barr virus (cfEBV) DNA load.

PATIENTS AND METHODS

We analyzed 695 patients with non-metastatic NPC and detectable post-treatment cfEBV DNA load who did not receive adjuvant therapy. We fitted the trajectories of post-treatment cfEBV DNA load as a function of time into a linear mixed-effect model and fitted a Cox regression model with covariates including age, T and N stages, and lactate dehydrogenase level. Finally, we combined both via joint modeling to develop and validate our dynamic model.

RESULTS

A strong positive correlation was found between the individual longitudinal post-treatment cfEBV DNA load and the risk of death from any cause (P < 0.001). We developed a joint model capable of providing subject-specific dynamic prediction of conditional OS based on the evolution of the individual plasma cfEBV DNA load trajectory. The joint model showed reliable performance in both training and validation cohorts, with a large area under the curve (interquartile range [IQR]: training cohort, 0.775-0.850; validation cohort, 0.826-0.900) and low prediction errors (IQR: training cohort, 0.017-0.078; validation cohort, 0.034 -0.071). An increasing amount of data on cfEBV DNA load was associated with better model performance.

CONCLUSION

Our model provided reliable subject-specific dynamic prediction of conditional OS, which could help guide individualized post-treatment surveillance, risk stratification, and management of NPC in the future.

Prognostic significance of AKR1C4 and the advantage of combining EBV DNA to stratify patients at high risk of locoregional recurrence of nasopharyngeal carcinoma

Background

Distinguishing patients at a greater risk of recurrence is essential for treating locoregional advanced nasopharyngeal carcinoma (NPC). This study aimed to explore the potential of aldo–keto reductase 1C4 (AKR1C4) in stratifying patients at high risk of locoregional relapse.

Methods

A total of 179 patients with locoregionally advanced NPC were grouped by different strategies; they were: (a) divided into two groups according to AKR1C4 expression level, and (b) classified into three clusters by integrating AKR1C4 and Epstein-Barr virus (EBV) DNA. The Kaplan–Meier method was used to calculate locoregional relapse-free survival (LRFS), overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). The Cox proportional hazards model was used to determine potential prognostic factors, and a nomogram was generated to predict 3-year and 5-year LRFS.

Results

A significant difference in the 5-year LRFS was observed between the high and low AKR1C4 expression groups (83.3% vs. 92.7%, respectively; p = 0.009). After integrating AKR1C4 expression and EBV DNA, the LRFS (84.7%, 84.5%, 96.9%, p = 0.014) of high-, intermediate-, and low- AKR1C4 and EBV DNA was also significant. Multivariate analysis indicated that AKR1C4 expression (p = 0.006) was an independent prognostic factor for LRFS. The prognostic factors incorporated into the nomogram were AKR1C4 expression, T stage, and EBV DNA, and the concordance index of the nomogram for locoregional relapse was 0.718.

Conclusions

In conclusion, high AKR1C4 expression was associated with a high possibility of relapse in NPC patients, and integrating EBV DNA and AKR1C4 can stratify high-risk patients with locoregional recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09924-3.

Surveillance tools for detection of recurrent nasopharyngeal carcinoma: An evidence-based review and recommendations

Objective

Nasopharyngeal carcinomas (NPC) are tumors arising from epithelium of the nasopharynx. The 5-year survival rate of primary NPC is 80% with significant risks of recurrence. The objective here is to provide an evidence-based systemic review of the diagnostic value of different modalities in detecting local, regional, and distal recurrent NPC, as well as the associated costs with these modalities.

Methods

MEDLINE, EMBASE, and the Cochrane review database were queried. Two hundred and twenty-three abstracts were generated using the inclusion criteria: patients >18 years of age; histopathological reference standard; and modalities pertaining to imaging or microbiology.

Results

Twenty-four manuscripts fulfilled the inclusion criteria and 5 surveillance tools identified: endoscopy, MR, FDG-PET, Tc-99m MIBI and ²⁰¹TI SPECT, and EBV DNA.

Conclusions

For local surveillance, endoscopy is the gold standard recommendation, with increased efficacy if Narrow Band Imaging or contact endoscopy are utilized. MRI and FDG-PET is also recommended to help with local to distal spread; however, Tc-99m MIBI and ²⁰¹TI SPECT are options as well. EBV DNA is recommended as a cheap and accessible adjunct surveillance tool if an available as an option.

Tracking the Molecular Fingerprint of Head and Neck Cancer for Recurrence Detection in Liquid Biopsies

The 5-year relative survival for patients with head and neck cancer, the seventh most common form of cancer worldwide, was reported as 67% in developed countries in the second decade of the new millennium. Although surgery, radiotherapy, chemotherapy, or combined treatment often elicits an initial satisfactory response, relapses are frequently observed within two years. Current surveillance methods, including clinical exams and imaging evaluations, have not unambiguously demonstrated a survival benefit, most probably due to a lack of sensitivity in detecting very early recurrence. Recently, liquid biopsy monitoring of the molecular fingerprint of head and neck squamous cell carcinoma has been proposed and investigated as a strategy for longitudinal patient care. These innovative methods offer rapid, safe, and highly informative genetic analysis that can identify small tumors not yet visible by advanced imaging techniques, thus potentially shortening the time to treatment and improving survival outcomes. In this review, we provide insights into the available evidence that the molecular tumor fingerprint can be used in the surveillance of head and neck squamous cell carcinoma. Challenges to overcome, prior to clinical implementation, are also discussed.

Development of a risk classification system combining TN-categories and circulating EBV DNA for non-metastatic NPC in 10,149 endemic cases

Background

The objective of this study was to construct a risk classification system integrating cell-free Epstein-Barr virus (cfEBV) DNA with T- and N- categories for better prognostication in nasopharyngeal carcinoma (NPC).

Methods

Clinical records of 10,149 biopsy-proven, non-metastatic NPC were identified from two cancer centers; this comprised a training (N = 9,259) and two validation cohorts (N = 890; including one randomized controlled phase 3 trial cohort). Adjusted hazard ratio (AHR) method using a two-tiered stratification by cfEBV DNA and TN-categories was applied to generate the risk model. Primary clinical endpoint was overall survival (OS). Performances of the models were compared against American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) 8th edition TNM-stage classification and two published recursive partitioning analysis (RPA) models, and were validated in the validation cohorts.

Results

We chose a cfEBV DNA cutoff of ⩾2,000 copies for optimal risk discretization of OS, disease-free survival (DFS) and distant metastasis-free survival (DMFS) in the training cohort. AHR modeling method divided NPC into six risk groups with significantly disparate survival (p  < 0.001 for all): AHR1, T1N0; AHR2A, T1N1/T2-3N0 cfEBV DNA  < 2,000 (EBV_low); AHR2B, T1N1/T2-3N0 cfEBV DNA ⩾ 2,000 (EBV_high) and T1-2N2/T2-3N1 EBV_low; AHR3, T1-2N2/T2-3N1 EBV_high and T3N2/T4N0 EBV_low; AHR4, T3N2/T4 N0-1 EBV_high and T1-3N3/T4N1-3 EBV_low; AHR5, T1-3N3/T4 N2-3 EBV_high. Our AHR model outperformed the published RPA models and TNM stage with better hazard consistency (1.35 versus 3.98-12.67), hazard discrimination (5.29 versus 6.69-13.35), explained variation (0.248 versus 0.164-0.225), balance (0.385 versus 0.438-0.749) and C-index (0.707 versus 0.662-0.700). In addition, our AHR model was superior to the TNM stage for risk stratification of OS in two validation cohorts (p  < 0.001 for both).

Conclusion

Herein, we developed and validated a risk classification system that combines the AJCC/UICC 8th edition TN-stage classification and cfEBV DNA for non-metastatic NPC. Our new clinicomolecular model provides improved OS prediction over the current staging system.

The Chinese Society of Clinical Oncology (CSCO) clinical guidelines for the diagnosis and treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa. To develop these comprehensive guidelines for the diagnosis and management of NPC, the Chinese Society of Clinical Oncology (CSCO) arranged a multi‐disciplinary team comprising of experts from all sub‐specialties of NPC to write, discuss, and revise the guidelines. Based on the findings of evidence‐based medicine in China and abroad, domestic experts have iteratively developed these guidelines to provide proper management of NPC. Overall, the guidelines describe the screening, clinical and pathological diagnosis, staging and risk assessment, therapies, and follow‐up of NPC, which aim to improve the management of NPC.

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.

Liquid biopsy posttreatment surveillance in endemic nasopharyngeal carcinoma: a cost-effective strategy to integrate circulating cell-free Epstein-Barr virus DNA

BACKGROUND

The optimal posttreatment surveillance strategy for nasopharyngeal carcinoma (NPC) remains unclear. Circulating cell-free Epstein-Barr virus (cfEBV) DNA has been recognized as a promising biomarker to facilitate early detection of NPC recurrence. Therefore, we aim to determine whether integrating circulating cfEBV DNA into NPC follow-up is cost-effective.

METHODS

For each stage of asymptomatic nonmetastatic NPC patients after complete remission to primary NPC treatment, we developed a Markov model to compare the cost-effectiveness of the following surveillance strategies: routine follow-up strategy, i.e., (1) routine clinical physical examination; routine imaging strategies, including (2) routine magnetic resonance imaging plus computed tomography plus bone scintigraphy (MRI + CT + BS); and (3) routine 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT); cfEBV DNA-guided imaging strategies, including (4) cfEBV DNA-guided MRI + CT + BS and (5) cfEBV DNA-guided PET/CT. Clinical probabilities, utilities, and costs were derived from published studies or databases. Sensitivity analyses were performed.

RESULTS

For all disease stages, cfEBV DNA-guided imaging strategies demonstrated similar survival benefits but were considerably more economical than routine imaging strategies. They only required approximately one quarter of the number of imaging studies compared with routine imaging strategies to detect one recurrence. Specifically, cfEBV DNA-guided MRI + CT + BS was most cost-effective for stage II (incremental cost-effectiveness ratio [ICER] $57,308/quality-adjusted life-year [QALY]) and stage III ($46,860/QALY) patients, while cfEBV DNA-guided PET/CT was most cost-effective for stage IV patients ($62,269/QALY). However, routine follow-up was adequate for stage I patients due to their low recurrence risk.

CONCLUSIONS

The cfEBV DNA-guided imaging strategies are effective and cost-effective follow-up methods in NPC. These liquid biopsy-based strategies offer evidence-based, stage-specific surveillance modalities for clinicians and reduce disease burden for patients.

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.

Circulating Epstein-Barr virus DNA level post induction chemotherapy contributes to prognostication in advanced-stage nasopharyngeal carcinoma

BACKGROUND

To investigate the value of post-induction chemotherapy (IC) cell-free Epstein-Barr virus DNA (cfEBV DNA_postIC) for prognostication in locally advanced nasopharyngeal carcinoma (LA-NPC).

METHODS

A total of 910 histologically proven LA-NPC undergoing radical IC + concurrent chemo-radiotherapy (CCRT) or targeted radiotherapy (CTRT) or both (CTCRT) were involved. The concentration of cfEBV DNA was measured by quantitative polymerase chain reaction pre-IC (cfEBV DNA_preIC) and at IC completion. CfEBV DNA_postIC was classified as undetectable (0 copy/ml) and detectable (>0 copy/ml). Recursive partitioning analysis (RPA) with respect to the overall survival (OS) was applied to construct a risk stratification system incorporating cfEBV DNA_postIC and critical risk factors.

RESULTS

We observed that 660 (72.5%) and 250 (27.5%) patients had cfEBV DNA_postIC undetectable and detectable respectively. CfEBV DNA_postIC positive was associated with a significant inferior 5-year OS (76.2% versus 85.9%), metastasis-free survival (DMFS, 71.7% versus 86.4%) and disease-free survival (DFS, 57.7% versus 80.1%) than cfEBV DNA_postIC negative (P < 0.001 for all). Additionally, cfEBV DNA_postIC was independently significant for OS (hazard ratio [HR] 1.90, 95% CI 1.40-2.59), DMFS (1.99, 1.45-2.71) and DFS (2.38, 1.86-3.06) in multivariate analyses (P < 0.001 for all). RPA modelling yielded three distinct risk groups: low-risk (N0-1 and undetectable cfEBV DNA_postIC or N2-3 and pre-treatment cfEBV DNA [cfEBV DNA_preIC] <7000), median-risk (N0-1 and detectable cfEBV DNA_postIC or N2-3 and cfEBV DNA_preIC ≥7000 with undetectable cfEBV DNA_postIC) and high-risk (N2-3 and cfEBV DNA_preIC ≥7000 with detectable cfEBV DNA_postIC), with 5-year OS of 88.1%, 79.2% and 66.9%, respectively. Our risk stratification outperformed TNM classification for predicting death (AUC, 0.631 versus 0.562; P = 0.012) and distant metastasis (0.659 versus 0.562; P = 0.004).

CONCLUSIONS

CfEBV DNA_postIC represents an effective indicator of prognostication in LA-NPC. We developed a risk classification system that provides improved OS prediction over the current staging system by combining cfEBV DNA_postIC, cfEBV DNA_preIC and N-stage classification in LA-NPC.

Dynamic Changes of Post-Radiotherapy Plasma Epstein-Barr Virus DNA in a Randomized Trial of Adjuvant Chemotherapy Versus Observation in Nasopharyngeal Cancer

PURPOSE

To study the dynamic changes in plasma Epstein-Barr virus (pEBV) DNA after radiotherapy in nasopharyngeal cancer (NPC).

EXPERIMENTAL DESIGN

We conducted a randomized controlled trial of adjuvant chemotherapy versus observation in patients with NPC who had detectable pEBV DNA at 6 weeks post-radiotherapy. Randomized patients had a second pEBV DNA checked at 6 months post-randomization. The primary endpoint was progression-free survival (PFS).

RESULTS

We prospectively enrolled 789 patients. Baseline post-radiotherapy pEBV DNA was undetectable in 573 (72.6%) patients, and detectable in 216 (27.4%) patients, of whom 104 (13.2%) patients were eligible for randomization to adjuvant chemotherapy (n = 52) versus observation (n = 52). The first post-radiotherapy pEBV DNA had a sensitivity of 0.48, specificity of 0.81, area under receiver-operator characteristics curve (AUC) of 0.65, false positive (FP) rate of 13.8%, and false negative (FN) rate of 14.4% for disease progression. The second post-radiotherapy pEBV DNA had improved sensitivity of 0.81, specificity of 0.75, AUC of 0.78, FP rate of 14.3%, and FN rate of 8.1%. Patients with complete clearance of post-radiotherapy pEBV DNA (51%) had survival superior to that of patients without post-radiotherapy pEBV DNA clearance (5-year PFS, 85.5% vs. 23.3%; HR, 9.6; P < 0.0001), comparable with patients with initially undetectable post-radiotherapy pEBV DNA (5-year PFS, 77.1%), irrespective of adjuvant chemotherapy or observation.

CONCLUSIONS

Patients with NPC with detectable post-radiotherapy pEBV DNA who experienced subsequent pEBV DNA clearance had superior survival comparable with patients with initially undetectable post-radiotherapy pEBV DNA. Post-radiotherapy pEBV DNA clearance may serve as an early surrogate endpoint for long-term survival in NPC.

The appropriate use of circulating EBV-DNA in nasopharyngeal carcinoma: Comprehensive clinical practice guidelines evaluation

BACKGROUND

In EBV-related nasopharyngeal carcinoma (NPC), quantitative determination of circulating EBV-DNA (cEBV-DNA) can potentially be applied as disease marker. The aim of the study was to investigate if the clinical utility of cEBV-DNA is established in clinical practice guidelines and if recommendations are provided to standardize the quantitative cEBV-DNA determination.

METHODS

A systematic literature search for NPC guidelines published since 2011 was performed. Information for cEBV-DNA detection method and use in clinical practice was synthesized in consecutive steps of increasing simplification.

RESULTS

From 570 titles and abstracts identified by the search, 16 guidelines were included. The selected documents were further clustered as either being based on a systematic literature revision to generate recommendations (4/16) or not (12/16). cEBV-DNA was evaluated in only one guideline based on a systematic revision and in 8 guidelines without systematic revision. Half of available guidelines provide recommendation for its clinical use. Methodological issues on cEBV-DNA determination are discussed by 31% of guidelines, without providing any recommendation on method standardization.

CONCLUSIONS

Due to its prognostic value, cEBV-DNA is suggested in the pre-treatment work-up and in the follow-up. Guideline producers need to take into more consideration methodological aspects impacting the actual reliability and generalizability of laboratory results.

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.

Lymph-node Epstein-Barr virus concentration in diagnosing cervical lymph-node metastasis in nasopharyngeal carcinoma

PURPOSE

Cervical lymph-node (CLN) metastasis commonly occurs in patients with nasopharyngeal carcinoma (NPC) metastasis. The presence of Epstein-Barr virus (EBV) genomes in neck lymph nodes may diagnose CLN. This research was designed to appraise the diagnostic value of EBV concentration for cervical lymph nodes in NPC.

METHODS

Two hundred and fifty-three NPC patients with 276 CLNs were enrolled. MRI was performed to detect CLN metastasis, and plasma EBV concentration was measured by quantitative PCR before treatment. Ultrasonography (US) and US-FNA were subsequently performed in the suspicious lymph nodes. Fifteen patients (22 lymph nodes) underwent fine-needle aspiration cytology (FNAC), and the remaining 242 patients (254 lymph nodes) underwent core needle biopsy (CNB) for CLNs at the clinician's demand. The aspiration needle was rinsed with 1 ml of normal saline for EBV detection. The method of lymph-node EBV measurement was consistent with that for plasma. The MRI results and EBV concentrations in plasma and lymph nodes were recorded and analyzed. Plasma EBV concentrations ≥ 4000 copies/ml were regarded as positive.

RESULTS

CLN-EBV concentrations ≥ 787.5 copies/ml were regarded as positive according to receiver-operating characteristic curve analysis. The AUC of the EBV (0.925) concentration in CLN metastasis was significantly larger than the AUC of MRI (0.714) (P < 0.001). The sensitivity and specificity were 94.09% and 48.72% for MRI in lymph-node metastasis and 95.36% (P > 0.05) and 84.62% (P < 0.01) for EBV DNA in CLN metastasis, respectively. The sensitivity and specificity of EBV in plasma were 77.2% and 71.8%, respectively. The diagnostic specificity and AUC of EBV in CLNs were higher than those of MRI and plasma EBV (P < 0.005).

CONCLUSIONS

Ultrasound-guided CLN FNA to obtain EBV concentrations may provide a new method to diagnose CLN metastasis with high sensitivity and specificity.

Epstein-Barr Virus DNA in Nasopharyngeal Carcinoma: A Brief Review

Epstein-Barr virus (EBV) is a B-lymphocytes herpes virus and can transform B lymphocytes to malignant tumor cells if infected. Nasopharyngeal carcinoma (NPC) is strongly associated with EBV. Circulating EBV DNA in plasma has been recognized as an important biomarker of NPC. Much work has been done to validate the ability of circulating EBV DNA for screening, diagnosis, risk stratification, monitoring, and predicting prognosis. This chapter reviews the clinical progress of circulating cell-free EBV DNA in NPC.

Liquid biopsy tracking during sequential chemo-radiotherapy identifies distinct prognostic phenotypes in nasopharyngeal carcinoma

Liquid biopsies have the utility for detecting minimal residual disease in several cancer types. Here, we investigate if liquid biopsy tracking on-treatment informs on tumour phenotypes by longitudinally quantifying circulating Epstein-barr virus (EBV) DNA copy number in 673 nasopharyngeal carcinoma patients undergoing radical induction chemotherapy (IC) and chemo-radiotherapy (CRT). We observe significant inter-patient heterogeneity in viral copy number clearance that is classifiable into eight distinct patterns based on clearance kinetics and bounce occurrence, including a substantial proportion of complete responders (≈30%) to only one IC cycle. Using a supervised statistical clustering of disease relapse risks, we further bin these eight subgroups into four prognostic phenotypes (early responders, intermediate responders, late responders, and treatment resistant) that are correlated with efficacy of chemotherapy intensity. Taken together, we show that real-time monitoring of liquid biopsy response adds prognostic information, and has the potential utility for risk-adapted treatment de-intensification/intensification in nasopharyngeal carcinoma.

Liquid biopsies are emerging as a useful method for diagnosis and prognosis in cancer. Here, the authors show the prognostic value of monitoring the level of circulating Epstein-barr virus DNA throughout induction chemotherapy and chemo-radiotherapy and its potential utility for risk-adapted individualised therapy in nasopharyngeal carcinomapatients.

Management of locally recurrent nasopharyngeal carcinoma

As a consequence of the current excellent loco-regional control rates attained using the generally accepted treatment paradigms involving intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC), only 10-20% of patients will suffer from local and/or nodal recurrence after primary treatment. Early detection of recurrence is important as localized recurrent disease is still potentially salvageable, but this treatment often incurs a high risk of major toxicities. Due to the possibility of radio-resistance of tumors which persist or recur despite adequate prior irradiation and the limited tolerance of adjacent normal tissues to sustain further additional treatment, the management of local failures remains one of the greatest challenges in this disease. Both surgical approaches for radical resection and specialized re-irradiation modalities have been explored. Unfortunately, available data are based on retrospective studies, and the majority of them are based on a small number of patients or relatively short follow-up. In this article, we will review the different salvage treatment options and associated prognostic factors for each of them. We will also propose a treatment algorithm based on the latest available evidence and discuss the future directions of treatment for locally recurrent NPC.

Fibronectin promotes nasopharyngeal cancer cell motility and proliferation

Nasopharyngeal cancer (NPC) is an Epstein-Barr virus (EBV)-associated carcinoma. Fibronectin is regarded as a prognosticator in NPC and its involvement in cell motility has been reported in EBV infection and viral latent membrane protein 1 (LMP1) overexpression NPC cell lines. However, its malignant potential in NPC cell lines without harbouring the EBV genome has not been investigated. We investigatd and compared among four NPC cell lines, and the results revealed a positive association between fibronectin levels and NPC cell motility as well as proliferation. Studies of antibody neutralization, exogenous addition, overexpression, and RNA interference confirmed a migration role of fibronectin in NPC cells involving integrin α5, Src, Rac1, and Cdc42, implying a mesenchymal-like cell movement. Furthermore, hypoxia-inducible factor-1α (HIF-1α) and transforming growth factor-β1 (TGF-β1) were identified as alternative activators of fibronectin expression and NPC cell migration. Besides cell migration, studies of RNA interference also showed a stimulatory effect of fibronectin in NPC cell proliferation. Mechanistic studies further revealed a subsequent reduction of HIF-1α, TGF-β1, cyclin D1, β-catenin, vimentin, and Slug together with decreased Src and Akt phosphorylation after fibronectin knockdown. Parallel studies in a xenograft tumor mice model further showed that tumor growth correlated well with elevation of circulating fibronectin and activation of the identified intracellular signaling molecules. The results of our study highlight a role of fibronectin in NPC cell motility and proliferation in concerted action with HIF-1α and TGF-β1 possibly through linking molecules Src and Akt. Fibronectin overexpression and autoantibody are known to have potential prognostic value in patients with NPC. Our findings shed light on the biochemical and molecular mechanisms underlying the pathogenic role of fibronectin in this disease.

LncRNA ZFAS1 promotes proliferation and migration and inhibits apoptosis in nasopharyngeal carcinoma via the PI3K/AKT pathway in vitro

BACKGROUND

Increasing evidence shows that long non-coding RNAs (lncRNAs) play a key role in the development of various cancers. Zinc finger antisense 1 (ZFAS1) is a novel lncRNA with previously demonstrated associations with several types of cancer. Here we examined the expression and potential function of the ZFAS1 in nasopharyngeal carcinoma (NPC).

METHODS

We detected ZFAS1 expression in GSE12452, a human microarray dataset, and NPC cell lines. Small interfering RNA against ZFAS1 was used to elucidate the cellular functions of ZFAS1 using MTT, colony formation, cell cycle, cell apoptosis, transwell invasion and migration and western blot assays. An activator of the PI3K/AKT signaling pathway (740Y-P) was used to determine the contribution of PI3K/AKT.

RESULTS

ZFAS1 was significantly upregulated in NPC tissues and cell lines. Silencing ZFAS1 significantly inhibited cell proliferation and invasion, arrested cell cycle progression and promoted cell apoptosis, as well as reduced epithelial-mesenchymal transition. Moreover, 740Y-P could rescue the effects of ZFAS1 knockdown on proliferation, apoptosis and invasion in 5-8F cells.

CONCLUSIONS

ZFAS1 might play an oncogenic role in NPC and facilitate cell proliferation and invasion via the PI3K/AKT signaling pathway in NPC cells.

Circulating Human Papillomavirus DNA as a Biomarker of Response in Patients With Locally Advanced Cervical Cancer Treated With Definitive Chemoradiation

Purpose

To determine whether plasma human papillomavirus (HPV) DNA predates clinical recurrence and compare its accuracy with 3-month fluorodeoxyglucose positron emission tomography (FDG-PET) in locally advanced cervical cancer.

Methods

This prospective multicenter study accrued 23 women with stage IB to IVA cervical cancer planned for definitive chemoradiation therapy (CRT). Plasma HPV DNA was measured serially by digital polymerase chain reaction, and FDG-PET was performed at 3 months post-CRT.

Results

Of the 19 women with HPV+ cervical cancer included in this analysis, 32% were stage IB, 58% IIB, and 10% IIIB/IVA. Median follow-up was 24 months (range, 18 to 30 months). All patients had detectable plasma HPV DNA before treatment. Six patients had detectable plasma HPV DNA at the end of CRT, and three of them developed metastases at 3 months. Of the 13 patients with undetectable plasma HPV DNA at end of CRT, to date, only one has developed recurrence. Six of those 13 patients had a positive 3-month FDG-PET with no definite residual disease on subsequent imaging or clinical examination to date, and four of these six had undetectable plasma HPV DNA at 3 months. Patients with undetectable plasma HPV DNA at end of CRT had significantly higher 18-month progression-free survival than those with detectable plasma HPV DNA (92% v 50%; P = .02). The area under the receiver operating characteristic curve (accuracy) of 3-month plasma HPV DNA and 3-month FDG-PET imaging for predicting recurrence at 18 months were 77% and 60%, respectively ( P = .008).

Conclusion

Detectable plasma HPV DNA at end of CRT predates the clinical diagnosis of metastases and is associated with inferior progression-free survival. Moreover, 3-month plasma HPV DNA level is more accurate than 3-month FDG-PET imaging in detecting residual disease. The clinical utility of plasma HPV DNA detection for guiding adjuvant/salvage therapy should be evaluated in future studies.

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.

Unusual axillary metastasis of recurrent nasopharyngeal cancer: A case report

RATIONALE

Nasopharyngeal carcinoma (NPC) has a high propensity of metastasis. The most commonly described sites of distant metastasis are the bones, lungs, and liver, whereas axillary metastasis is seldom reported.

PATIENT CONCERNS

We hereby present the case of a 66-year-old man with NPC, cT2N2M0, at diagnosis. He had completed chemoradiotherapy and been disease-free for 7 years.

DIAGNOSES

After that period, late recurrence in the form of a solitary axillary lymph node metastasis was detected and confirmed by core-needle biopsy.

INTERVENTIONS

The lesion was chemoresistant but responded to salvage radiotherapy at a dose of 65 Gy in 21 fractions.

OUTCOMES

Post-radiotherapy positron emission tomography scan showed no evidence of disease.

LESSONS

We suggested that long-term follow-up of NPC patients is important because a late relapse may occur at an unusual site. Aggressive management of solitary metastasis may achieve good outcome.

Molecular Imaging and Precision Medicine in Head and Neck Cancer

The concept of using tumor genomic profiling information has revolutionized personalized cancer treatment. Head and neck (HN) cancer management is being influenced by recent discoveries of activating mutations in epidermal growth factor receptor and related targeted therapies with tyrosine kinase inhibitors, targeted therapies for Kristen Rat Sarcoma, and MET proto-oncogenes. Molecular imaging using PET plays an important role in assessing the biologic behavior of HN cancer with the goal of delivering individualized cancer treatment. This review summarizes recent genomic discoveries in HN cancer and their implications for functional PET imaging in assessing response to targeted therapies, and drug resistance mechanisms.

IL-8 suppresses E-cadherin expression in nasopharyngeal carcinoma cells by enhancing E-cadherin promoter DNA methylation

Nasopharyngeal carcinoma (NPC) has the highest metastasis potential among head and neck cancers. Distant metastasis is the major cause of treatment failure. Recent studies from our laboratory have revealed that IL-8 promotes NPC metastasis via activation of AKT signaling and induction of epithelial-mesenchymal transition (EMT) in the cells. In the present study, we found that IL-8 treatment for NPC cells resulted in an accumulation of DNMT1 protein through activating AKT1 pathway and consequent DNMT1 protein stabilization. Then DNMT1 suppressed E-cadherin expression by increasing the methylation of its promoter region. LY-294002 blocked IL-8-induced p-AKT1 activation resulting in reduction of DNMT1 and increase of E-cadherin expression, whereas forced demethylation using 5-aza-2'-deoxycytidine restored E-cadherin expression. In conclusion, our study, for the first time, shows that the IL-8/AKT1 signaling pathway stabilizes DNMT1 protein, consequently enhancing hypermethylation of E-cadherin promoter regions and downregulating E-cadherin protein level in NPC cells. Upon blockage of the IL-8/AKT pathway and inhibition of DNMT1, E-cadherin expression can be reversed. These data suggest that targeting the IL-8/AKT1 signaling pathway and DNMT1 may provide a potential therapeutic approach for blocking NPC metastasis.

Nasopharyngeal Cancer: Molecular Landscape

Nasopharyngeal carcinoma (NPC) is a unique epithelial malignancy arising from the superior aspect of the pharyngeal mucosal space, associated with latent Epstein-Barr virus infection in most cases. The capacity to characterize cancer genomes in unprecedented detail is now providing insights into the genesis and molecular underpinnings of this disease. Herein, we provide an overview of the molecular aberrations that likely drive nasopharyngeal tumor development and progression. The contributions of major Epstein-Barr virus–encoded factors, including proteins, small RNAs, and microRNAs, along with their interactions with pathways regulating cell proliferation and survival are highlighted. We review recent analyses that clearly define the role of genetic and epigenetic variations affecting the human genome in NPC. These findings point to the impact of DNA methylation and histone modifications on gene expression programs that promote this malignancy. The molecular interactions that allow NPC cells to evade immune recognition and elimination, which is crucial for the survival of cells expressing potentially immunogenic viral proteins, are also described. Finally, the potential utility of detecting host and viral factors for the diagnosis and prognosis of NPC is discussed. Altogether, the studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC, yet much remains to be uncovered. Emerging techniques for using and analyzing well-annotated biospecimens from patients with NPC will ultimately lead to a greater level of understanding, and enable improvements in precision therapies and clinical outcomes.

False-positive finding of retropharyngeal lymph node recurrence in both fluorine (18)FDG PET and MRI in a patient with nasopharyngeal carcinoma

BACKGROUND

Biopsy of the retropharyngeal node is not routinely accessible. The diagnosis of retropharyngeal lymph node recurrence in patients with nasopharyngeal carcinoma (NPC) is often based on an imaging study.

METHODS

We reported a patient with NPC who was incorrectly diagnosed with left retropharyngeal lymph node recurrence by both MRI and positron emission tomography (PET)/CT.

RESULTS

A woman who was treated for stage IVA NPC 2 years previously was found to have a nodal lesion in the left retropharyngeal space on MRI together with focal fluorodeoxyglucose (FDG) uptake on PET/CT. Locoregional recurrence was suspected, and surgery was performed. Subsequent pathology results showed reactive lymphoid hyperplasia.

CONCLUSION

Although tissue biopsy for the retropharyngeal node is technically difficult, this case demonstrates that tumor recurrence cannot be diagnosed even based on both positive findings on MRI and PET/CT in patients with NPC.

The clinical utility of plasma Epstein-Barr virus DNA assays in nasopharyngeal carcinoma: the dawn of a new era?: a systematic review and meta-analysis of 7836 cases

In this study, we assessed the potential of plasma Epstein-Barr virus (EBV) DNA assays to predict clinical outcomes in a large sample of nasopharyngeal carcinoma (NPC) patients and proposed a risk stratification model based on standardized EBV DNA load monitoring.We conducted a meta-analysis of 14 prospective and retrospective comparative studies (n = 7 836 patients) to evaluate the correlation between pretreatment plasma EBV DNA (pre-DNA), midtreatment plasma EBV DNA (mid-DNA), posttreatment plasma EBV DNA (post-DNA), the half-life value of plasma EBV DNA clearance rate (t1/2), and clinical outcomes. Our primary endpoint was overall survival (OS). Our secondary endpoints were progression-free survival (PFS), distant-metastasis-free survival (DMFS), and local-regional-failure-free survival (LRFS).High pre-DNA, detectable mid-DNA, detectable post-DNA, and slow EBV DNA clearance rates were all significantly associated with poorer OS, with hazard radios (HRs) equal to 2.81, 3.29, 4.26, and 3.58, respectively. Pre-DNA, mid-DNA, and post-DNA had the same effects on PFS, DMFS, and LRFS.Plasma EBV DNA assays are highly prognostic of long-term survival and distant metastasis in NPC patients. Based on the results of this meta-analysis, we propose a 4-grade systematic risk stratification model. Given the inherent limitations of the included studies, future well-designed randomized clinical trials are required to confirm to the findings of this analysis and to contribute to the development of individualized treatment strategies for NPC patients.

Understanding the interplay between host immunity and Epstein-Barr virus in NPC patients

Epstein-Barr virus (EBV) has been used as a paradigm for studying host-virus interactions, not only because of its importance as a human oncogenic virus associated with several malignancies including nasopharyngeal carcinoma (NPC) but also owing to its sophisticated strategies to subvert the host antiviral responses. An understanding of the interplay between EBV and NPC is critical for the development of EBV-targeted immunotherapy. Here, we summarize the current knowledge regarding the host immune responses and EBV immune evasion mechanisms in the context of NPC.

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.

Plasma Epstein-Barr virus DNA as a biomarker for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is common in southern China and Southeast Asia. Epstein-Barr virus (EBV) infection is an important etiology for NPC, and EBV genome can be detected in almost all tumor tissues of NPC in this region. Plasma EBV DNA, when quantitatively analyzed using real-time polymerase chain reaction (PCR), has been developed as a biomarker for NPC. In this review, the different clinical applications of plasma EBV DNA in the management of NPC, including screening, monitoring, and prognostication, are discussed. In addition, the biological issues of circulating EBV DNA, including the molecular nature and clearance kinetics, are also explored.

The impact of plasma Epstein-Barr virus DNA and fibrinogen on nasopharyngeal carcinoma prognosis: an observational study

BACKGROUND

The impact of combining plasma fibrinogen levels with Epstein-Barr Virus DNA (EBV DNA) levels on the prognosis for patients with nasopharyngeal carcinoma (NPC) was evaluated.

METHODS

In this observational study, 2563 patients with non-metastatic NPC were evaluated for the effects of circulating plasma fibrinogen and EBV DNA levels on disease-free survival (DFS), distant metastasis-free survival (DMFS), and overall survival (OS).

RESULTS

Compared with the bottom biomarker tertiles, TNM stage-adjusted hazard ratios (HR, 95% confidence intervals (CIs)) for predicting DFS in fibrinogen tertiles 2 to 3 were 1.26 (1.00 to 1.60) and 1.81 (1.45 to 2.26), respectively; HR for EBV DNA tertiles 2 to 3 were 1.49 (1.12 to 1.98) and 4.24 (3.27 to 5.49), respectively. After additional adjustment for established risk factors, both biomarkers were still associated (P for trend <0.001) with reduced DFS (HR: 1.79, 95% CI, 1.43 to 2.25 for top fibrinogen tertiles; HR: 4.04, 95% CI: 3.10 to 5.27 for top EBV DNA tertiles compared with the bottom tertiles). For patients with advanced-stage disease, those with high fibrinogen levels (3.34 g l(-1)) presented with worse DFS, regardless of EBV DNA 4000 or <4000 copies ml(-1) subgroup. Similar findings were observed for DMFS and OS.

CONCLUSIONS

Circulating fibrinogen and EBV DNA significantly correlate with NPC patients survival. Combined fibrinogen and EBV DNA data lead to improved prognostic prediction in advanced-stage disease.

[Nasopharyngeal cancers, an overview]

Cancer of the nasopharynx is an uncommon malignancy in France (incidence  =  0.5/year/100,000 men) but is endemic in areas like in South-East Asia. Exclusive radiation therapy used to be the standard and results in local control rates for T3-T4 tumors around 50-75 %. Intensity-modulated radiotherapy (IMRT) improves tumor coverage with a sparing of organs at risk and has to be privileged. Concurrent chemotherapy with IMRT achieved significant survival benefice with 5-year overall survival above 75 %. Concurrent radiochemotherapy with platinum is the most frequent scheme but induction and adjuvant chemotherapies are discussed to reduce distant failure: studies are currently ongoing. Follow-up aims to detect early local failures with a chance of cure and to manage long-term toxicities.

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.

Current treatment options for local residual nasopharyngeal carcinoma

OPINION STATEMENT

Local residual disease occurs in 7-13 % after primary treatment for nasopharyngeal carcinoma (NPC). To prevent tumor progression and/or distant metastasis, treatment is indicated. Biopsy is the "gold standard" for diagnosing residual disease. Because late histological regression frequently is seen after primary treatment for NPC, biopsy should be performed when imaging or endoscopy is suspicious at 10 weeks. Different modalities can be used in the treatment of local residual disease. Interestingly, the treatment of residual disease has better outcomes than treatment of recurrent disease. For early-stage disease (rT1-2), treatment results and survival rates are very good and comparable to patients who had a complete response after the first treatment. Surgery (endoscopic or open), brachytherapy (interstitial or intracavitary), external or stereotactic beam radiotherapy, or photodynamic therapy all have very good and comparable response rates. Choice should depend on the extension of disease, feasibility of the treatment, and doctor's and patient's preferences and experience, as well as the risks of the adverse events. For the more extended tumors, choice of treatment is more difficult, because complete response rates are poorer and severe side effects are not uncommon. The results of external beam reirradiation and stereotactic radiotherapy are better than brachytherapy for T3-4 tumors. Photodynamic therapy resulted in good palliative responses in a few patients with extensive disease. Also, chemotherapeutics or the Epstein-Barr virus targeted therapies can be used when curative intent treatment is not feasible anymore. However, their advantage in isolated local failure has not been well described yet. Because residual disease often is a problem in countries with a high incidence of NPC and limited radiotherapeutic and surgical facilities, it should be understood that most of the above mentioned therapeutic modalities (radiotherapy and surgery) will not be readily available. More research with controlled, randomized trials are needed to find realistic treatment options for residual disease.

Prognostic implications of post-therapy (18)F-FDG PET in patients with locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy

OBJECTIVES

Reliable prognostic factors that serve as a guide to follow-up of patients with locoregionally advanced nasopharyngeal carcinoma (NPC) have not yet been identified. We sought to investigate the prognostic implications of post-therapy PET in patients with NPC treated with chemoradiotherapy.

METHODS

Patients with locoregionally advanced NPC (stages III and IVa-b) who had completed primary curative treatment for 3 months were eligible. All of the patients underwent (18)F-FDG PET and conventional work-up (CWU) for the assessment of treatment response.

RESULTS

A total of 165 patients were enrolled. Over a median follow-up of 58 months, 30 patients died and 41 had disease recurrence. The results of the 3-month post-therapy PET and total lesion glycolysis (TLG) of the primary tumor were independent predictors of overall survival. TNM tumor stage, TLG, and post-therapy PET findings were independently associated with disease-free survival (DFS). The results of post-therapy PET were more predictive of DFS than TNM tumor stage (P < 0.001 vs. P = 0.005). Among patients with stage IVa-b disease, there was a trend toward better 5-DFS rates in patients with a complete metabolic response (CMR) on PET than in those who showed a complete response in the CWU (5-year DFS = 70.7 vs. 63.1 %). Notably, the 1- and 2-year DFS rates were significantly better in the former group compared with the latter. In contrast, the results of post-therapy CWU were not a reliable predictor for DFS.

CONCLUSION

The results of post-therapy PET are an important independent prognostic factor in locoregionally advanced NPC. CMR on PET is associated with better DFS rates and could serve as a guidance to individualize the surveillance protocols for patients with stage IVa-b disease.

Clinical scenario of EBV DNA follow-up in patients of treated localized nasopharyngeal carcinoma

OBJECTIVE

In this study, we investigated the usefulness and limitations of EBV-DNA follow-up in patients who had treated localized nasopharyngeal carcinoma.

METHODS

Study subjects comprised 389 patients who had received treatment for localized nasopharyngeal carcinoma in our department. Copy numbers of EBV-DNA in plasma were assessed by real-time quantitative PCR. Patients in whom disease recurrence was suspected underwent image evaluation, esp. PET scan, and tissue proof if it is feasible. Lesions of undermined nature were confirmed by sequential follow-up.

RESULTS

Plasma EBV-DNA was detectable in 60 of 63 (95%) patients with metastatic disease and all had positive PET findings. In addition, of the 45 patients with localized recurrent disease, plasma EBV-DNA was detectable in 23 (51%) patients and positive PET scan results were obtained in 40 (89%) of the patients. Of the 284 patients who were disease free, plasma EBV-DNA was detected in 90 (32%) patients. Of the 19 patients in disease free group who were suspected disease recurrence receiving PET scanning, 7 positive PET images were found including 3 second primary malignancy and 4 non-cancer lesions. Two lymphoma cases with positive EBV-DNA value sequentially attacked before or after their NPC were diagnosed. With the cutoff value of 400copies/ml of EBV-DNA, the positive predict value was 73.5% and the negative predict value was 82.1%. The sensitivity was 0.46 and the specificity was 0.94.

CONCLUSIONS

EBV-DNA was a good marker for detecting metastatic failure in treated localized NPC. However, careful interpretation with complements from image examination was needed for locoregional failure and other false positive or false negative situations.