Integrating pre- and post-treatment Plasma Epstein-Barr Virus DNA levels for better prognostic prediction of Nasopharyngeal Carcinoma

Oncogenic virus integration: Moving toward clinical applications

The majority of oncogenic viruses are capable of integrating into the host genome, posing significant challenges to clinical control. Recent conceptual and technological advances, however, offer promising clinical applications. Here, we summarize the advances in our understanding of oncogenic viral integration, their clinical relevance, and the future perspectives.

Clinical relevance of plasma EBV DNA as a biomarker for nasopharyngeal carcinoma in non-endemic areas: A multicenter study in southwestern China

BACKGROUND

Numerous clinical studies have validated plasma EBV DNA as a reliable biomarker for nasopharyngeal carcinoma (NPC) screening, tumor load monitoring, and prognosis prediction in endemic regions. However, the clinical relevance of plasma EBV DNA as a biomarker for NPC in non-endemic areas is still unclear.

METHOD

The pretreatment plasma EBV DNA of 1405 newly diagnosed NPC patients from three major regional hospitals in non-endemic areas were analyzed retrospectively. The medical records of 244 age- and gender-matched healthy individuals were reviewed. EBV DNA was detected using Polymerase Chain Reaction (PCR). Based on the baseline of 400 and 0 copies/mL, the distribution characteristics of the pretreatment EBV DNA load in different clinical stages and geographic regions were analyzed. The diagnostic value of pretreatment plasma EBV DNA for NPC with two baselines was evaluated using the ROC curve.

RESULTS

NPC patients had a significantly higher pretreatment EBV DNA level than healthy controls (P＜0.001). Pretreatment EBV DNA was closely associated with clinical and TNM stages in non-endemic areas, as it was in endemic areas. However, when 400 copies/mL set as the detection baseline, the sensitivity and specificity for NPC diagnosis were 40.8 % and 100 %, respectively (AUC = 0.704, cut off = 200.5 copies/mL). This sensitivity was lower than that reported in endemic regions (41.5 % - 97.1 %). Lower sensitivity may result in false negatives, missing diagnoses during NPC screening. Further investigation revealed that 39.7 % (558/1405) of NPC patients had detectable EBV DNA and S amplification curves. Optimizing the detection limit to 0 copies/mL, the sensitivity could be improved to 80.5 % (AUC = 0.901).

CONCLUSIONS

In non-endemic areas, the clinical significance of plasma EBV DNA as a biomarker for NPC was restricted due to the low detection limit of 400 copies/mL. More efficient nucleic acid extraction and detection methods are needed to optimize the detection limit and increase the clinical application of plasma EBV DNA for NPC.

The role of Epstein-Barr virus in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a metastasis-prone malignancy closely associated with the Epstein-Barr virus (EBV). Despite ubiquitous infection of EBV worldwide, NPC incidences displayed predominance in certain ethnic groups and endemic regions. The majority of NPC patients are diagnosed with advanced-stage disease, as a result of anatomical isolation and non-specific clinical manifestation. Over the decades, researchers have gained insights into the molecular mechanisms underlying NPC pathogenesis as a result of the interplay of EBV infection with several environmental and genetic factors. EBV-associated biomarkers were also used for mass population screening for the early detection of NPC. EBV and its encoded products also serve as potential targets for the development of therapeutic strategies and tumour-specific drug delivery. This review will discuss the pathogenic role of EBV in NPC and efforts in exploiting the potential of EBV-associated molecules as biomarkers and therapeutic targets. The current knowledge on the role of EBV and its associated products in NPC tumorigenesis, development and progression will offer a new outlook and potential intervention strategy against this EBV-associated malignancy.

The Dynamic Change in Plasma Epstein-Barr Virus DNA Load over a Long-Term Follow-Up Period Predicts Prognosis in Nasopharyngeal Carcinoma

The current study was designed to investigate the changes in the circulating Epstein−Barr virus DNA load (EBV DNA) at various time points before and after treatment and its clinical significance in nasopharyngeal carcinoma (NPC). A total of 142 patients with NPC were prospectively enrolled in this study. The plasma EBV DNA concentration was measured before and after treatment using qPCR. The prognostic values of the EBV DNA load were analyzed using the Kaplan−Meier and Cox regression tests. Following multivariate analysis, our data showed that high pre-EBV DNA loads were associated with significantly poorer distant metastasis free survival (DMFS) and progression free survival (PFS); detectable end-EBV DNA loads were associated with significantly worse loco-regional recurrence free survival (LRRFS) and PFS, and the detecTable 6 months-post-EBV DNA loads were associated with significantly poorer overall survival (OS), DMFS and PFS (p < 0.05). Additionally, combining the pre-EBV DNA load and the stage of the disease, our results showed that patients at stage III-IVA with a low pre-EBV DNA load had similar survival rates as patients at stage II with a low or high pre-EBV DNA load, but had better survival rates than those at stage III-IVA with a high pre-EBV DNA load. Taken together, we showed that the change of the EBV DNA load measured at several time points was more valuable than at any single time point for predicting patients’ survival for NPC. Furthermore, combining the pre-EBV DNA load and the TNM classification could help to formulate an improved prognostic model for this cancer.

Combination of smoking and Epstein-Barr virus DNA is a predictor of poor prognosis for nasopharyngeal carcinoma: a long-term follow-up retrospective study

BACKGROUND

This retrospective study was performed to determine the prognostic potential of smoking and its combination with pre-treatment plasma Epstein-Barr virus (EBV) DNA levels in patients with nasopharyngeal carcinoma (NPC).

METHODS

Medical records of 1080 non-metastatic NPC patients who received intensity-modulated radiotherapy were reviewed. Male patients were categorized as never and ever smokers, and the smoking amount, duration, and cumulative consumption were used to evaluate dose-dependent effects. Survival outcomes were assessed using Kaplan-Meier survival analysis and the multivariate Cox regression analysis. Propensity score matching (PSM) was constructed.

RESULTS

The 5-year overall survival (OS) was worse for ever smokers than never smokers, and significantly decreased with the increase of smoking amount, duration, and cumulative consumption. Compared with never smokers, the multivariate-adjusted hazard ratio (HR) of death was higher in ever smokers (HR = 1.361, P = 0.049), those smoked ≥20 cigarettes/day (HR = 1.473, P = 0.017), those smoked for ≥30 years (HR = 1.523, P = 0.023), and those cumulative smoked for ≥30 pack-years (HR = 1.649, P = 0.005). The poor prognostic effects of smoking was also confirmed in the PSM analysis. The combination of cumulative smoking consumption and pre-treatment EBV DNA levels was proven to be an independent poor prognostic factor for male NPC, and the risk of death, progression, and distant metastases gradually increased with both factors (P < 0.001).

CONCLUSIONS

Combination of smoking and pre-treatment EBV DNA levels as a predictor of poor prognosis could further improve the risk stratification and prognostication for NPC.

Development and validation of an MRI-based radiomic model for predicting overall survival in nasopharyngeal carcinoma patients with local residual tumors after intensity-modulated radiotherapy

BACKGROUND

To investigate the potential value of the pretreatment MRI-based radiomic model in predicting the overall survival (OS) of nasopharyngeal carcinoma (NPC) patients with local residual tumors after intensity-modulated radiotherapy (IMRT).

METHODS

A total of 218 consecutive nonmetastatic NPC patients with local residual tumors after IMRT [training cohort (n = 173) and validation cohort (n = 45)] were retrospectively included in this study. Clinical and MRI data were obtained. Univariate Cox regression and the least absolute shrinkage and selection operator (LASSO) were used to select the radiomic features from pretreatment MRI. The clinical, radiomic, and combined models for predicting OS were constructed. The models' performances were evaluated using Harrell's concordance index (C-index), calibration curve, and decision curve analysis.

RESULTS

The C-index of the radiomic model was higher than that of the clinical model, with the C-index of 0.788 (95% CI 0.724-0.852) versus 0.672 (95% CI 0.599-0.745) in the training cohort and 0.753 (95% CI 0.604-0.902) versus 0.634 (95% CI 0.593-0.675) in the validation cohort. Calibration curves showed good agreement between the radiomic model-predicted probability of 2- and 3-year OS and the actual observed probability in the training and validation groups. Decision curve analysis showed that the radiomic model had higher clinical usefulness than the clinical model. The discrimination of the combined model improved significantly in the training cohort (P < 0.01) but not in the validation cohort, with the C-index of 0.834 and 0.734, respectively. The radiomic model divided patients into high- and low-risk groups with a significant difference in OS in both the training and validation cohorts.

CONCLUSIONS

Pretreatment MRI-based radiomic model may improve OS prediction in NPC patients with local residual tumors after IMRT and may assist in clinical decision-making.

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 value of systemic inflammation response index in nasopharyngeal carcinoma with negative Epstein-Barr virus DNA

Background

Inflammatory parameters and Epstein–Barr virus (EBV) DNA status have been confirmed to be associated with prognosis in nasopharyngeal carcinoma (NPC) patients. However, there are few in-depth studies on the prognosis of NPC patients with negative EBV DNA. Our study aimed to look for inflammatory biomarkers that can identify disease progression in NPC patients with negative EBV DNA.

Methods

A total of 795 NPC patients were recruited, and ultimately 325 NPC patients with negative EBV DNA were included in this study (170 in training cohort and 155 in validation cohort). Kaplan–Meier method and log-rank test were used to analyze progression-free survival (PFS) and overall survival (OS). The multivariate analysis of Cox proportional hazards regression model was used to determine the independent prognostic factors. Receiver operating characteristic (ROC) curves were used to assess prognostic value. The logistic regression was used to evaluate the relationship between EBV DNA status and inflammatory parameters. The correlation between clinical characteristics was analyzed by the chi-squared test or the Fisher’s exact test.

Results

The optimal cutoff point for the SIRI was 1.12. The EBV DNA-negative NPC patients with high SIRI level had worse PFS and OS (all p < 0.001). In multivariate Cox proportional hazard models analysis, SIRI was an independent prognostic factor for PFS and OS (all p < 0.05), and had higher prognostic value than other indicators. Above results were found in the training cohort and confirmed in the validation cohort. In addition, EBV DNA status was not associated with any inflammatory parameters.

Conclusions

The SIRI can provide more accurate risk stratification and better prognostic prediction for NPC patients with negative EBV DNA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09942-1.

Plasma Epstein-Barr viral DNA load after completion of two cycles of induction chemotherapy predicts outcomes for patients with advanced-stage nasopharyngeal carcinoma

OBJECTIVES

To evaluate the prognostic value of plasma Epstein-Barr virus DNA level following the completion of two induction chemotherapy cycles (ICT; post_2CICT-DNA) in locoregionally advanced nasopharyngeal carcinoma (LA-NPC).

MATERIALS AND METHODS

This retrospective study included 534 patients with LA-NPC. Recursive partitioning analysis (RPA) was applied to derive a prognostic model for risk stratification. Kaplan-Meier survival analysis was used to determine the survival results, and survival rates were compared using the log-rank test. The Cox proportional hazard model was used for univariate and multivariate analyses.

RESULTS

Multivariate analyses revealed that post_2CICT-DNA and N stage were independent predictors of overall survival (OS; P = 0.001 and P = 0.001, respectively), and post_2CICT-DNA, pre-treatment DNA, and N stage were independent predictors of progression-free survival (PFS; P = 0.002, P = 0.001, and P = 0.021, respectively).Based on prognostic factors (pre-treatment DNA, post_2CICT-DNA, and N stage), patients were stratified into three risk subgroups, with 288 patients in the low-, 213 in the intermediate-, and 33 in the high-risk group. The three-year OS rate of the low-, intermediate- and high-risk groups were 99.3% (95% CI 98.3%-100.0%), 90.0% (95% CI 85.5%-94.5%) and 67.0% (95% CI 49.9%-84.1%, P < 0.001 for each of the two groups), respectively.

CONCLUSION

Plasma EBV-DNA level after two ICT cycles is a powerful predictor of prognosis in patients with LA-NPC. RPA analysis revealed that stage N3 patients with detectable post_2CICT-DNA are at the highest risk of treatment failure, and future clinical trials should focus on early-treatment modification strategies for these patients.

Association of Epstein-Barr virus DNA and SAA with S1 maintenance therapy outcomes in patients with metastatic nasopharyngeal carcinoma

Objectives: The relevant biomarkers in predicting maintenance therapy (MT) outcomes in metastatic nasopharyngeal carcinoma (NPC) are yet unclear. Patients & methods: Metastatic NPC patients were randomly divided into MT (S1-MT) and non-MT groups. The association of Epstein-Barr virus DNA (EBV-DNA) and SAA with survival was assessed. Results: A total of 183 patients were included. S1-MT significantly increased the progression-free survival (PFS) and overall survival (OS) of the metastatic NPC patients (both p < 0.001). For patients who were EBV-DNA positive or had decreased SAA, the PFS and OS increased significantly after S1-MT (both p < 0.001), while patients with stable SAA did not benefit from S1-MT. Conclusion: S1-MT improved the PFS and OS of metastatic NPC patients. EBV-DNA and SAA status were closely associated with the outcomes of S1-MT. Clinical trial registration number: ChiCTR-IOR-16007939.

Epstein-Barr virus nuclear antigen-1 is useful as therapeutic efficacy marker in serum but not in saliva of nasopharyngeal cancer patients who underwent radiotherapy

Introduction

Nasopharyngeal carcinoma (NPC) is a multifactorial disease with genetic, viral, environmental and lifestyle-related risk factors. Epstein–Barr virus (EBV) can promote the oncogenic transformation of an infected cell into malignant. EBV encodes many stimulating products including Epstein–Barr virus nuclear antigen-1 (EBNA-1) which plays a key role in the regulation of gene expression and replication of the genome in the latent period of infection. EBNA-1 in serum and tumour tissue of NPC patients correlates with NPC prognosis. Moreover, the presence of EBV DNA in serum samples from NPC patients’ blood circulation can be used as an early marker in the diagnosis of NPC.

Objective

The objective of this study was to find effective methods for monitoring the progress of NPC patients undergoing radiotherapy and therapeutic efficacy by observing the changes in EBV DNA in serum and saliva.

Methodology

The pre-experimental design compared blood and saliva taken from a pre-test and post-test group of NPC patients before and after radiation therapy. The concentration of EBV DNA was measured in the serum and saliva after amplification using quantitative polymerase chain reaction (qPCR) with compatible primers for the EBNA-1 gene. The data were statistically analysed by paired T-test.

Results

Highly significant (p = 0.0001) increase in cycle threshold qPCR and decrease in the mean concentration of EBV DNA (p = 0.0001) were observed in serum samples, but no significant changes were observed in saliva.

Conclusions

The results suggest that EBV DNA in serum can be used as the gold standard and a marker for monitoring the response to radiation therapy in NPC patients, whereas the examination of EBV DNA from saliva samples is not accurate and thus, not appropriate.