Prognostication of serial post-intensity-modulated radiation therapy undetectable plasma EBV DNA for nasopharyngeal carcinoma

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.

Significance of longitudinal Epstein-Barr virus DNA combined with multipoint tumor response for dynamic risk stratification and treatment adaptation in nasopharyngeal carcinoma

Dynamic therapy response is strongly associated with cancer outcomes. This study aimed to evaluate the significance of longitudinal Epstein-Barr virus (EBV) DNA and radiological tumor regression in risk stratification and response-adaptive treatment in locally-advanced nasopharyngeal carcinoma (LA-NPC). In total, 1312 patients from two centers were assigned to the training and validation cohorts. Based on the multipoint examination of EBV-DNA and tumor response, four post-induction chemotherapy, four mid-radiotherapy, and four post-radiotherapy subgroups were established. Then seven phenotypes were further generated according to different permutations and combinations. These phenotypes were subsequently congregated into four response clusters, which reflect distinct biological treatment responses. The four response clusters correlated with an evident 5-year progression-free survival in both the training and external validation cohorts (5-year: training cohort 91.1 %, 82.8 %, 30.6 %, and 10.0 %; external validation 94.4 %, 55.6 %, 40.0 %, and 12.7 %) had superior prognostic performance compared to TNM staging and nomogram model (concordance index: training cohort-0.825 vs. 0.603 vs. 0.756 and external validation-0.834 vs. 0.606 vs. 0.789). Importantly, the response clusters exhibited an excellent capability in selecting candidates who can benefit from adjuvant chemotherapy. In conclusion, risk stratification based on the dynamic assessment of both radiological and biological responses can significantly enhance prognostic insights and shed light on individualized treatment modifications in LA-NPCs.

Longitudinal on-treatment circulating tumor DNA as a biomarker for real-time dynamic risk monitoring in cancer patients: The EP-SEASON study

Recurrence risks of cancer patient can change during treatment as a result of treatment-related tumor evolution. However, biomarkers that can monitor these changes are lacking. Here, we investigated whether tracking circulating tumor DNA (ctDNA) dynamics through liquid biopsy can inform real-time recurrence risk. Nasopharyngeal carcinoma (NPC) provides an ideal model where cell-free Epstein-Barr virus (EBV) DNA (cfEBV DNA), a ctDNA, can be sensitively detected. We conducted the EP-SEASON study (NCT03855020) and prospectively recruited 1,000 NPC patients undergoing per-protocol cfEBV DNA assessments at 11 time points and receiving sequential chemo-radiotherapy. Longitudinal cfEBV DNA displayed distinct patterns during neoadjuvant chemotherapy and radiotherapy. Despite the prognostic significance of cfEBV DNA at each time point, real-time recurrence risks changed in sync with cfEBV DNA dynamics. Furthermore, we identified phenotypes of whole-course ctDNA changing dynamics associated with different survival outcomes. In conclusion, tracking longitudinal on-treatment ctDNA can forecast real-time recurrence risk, facilitating risk-adapted, individualized patient management.

Precision Medicine for Nasopharyngeal Cancer-A Review of Current Prognostic Strategies

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV) driven malignancy arising from the nasopharyngeal epithelium. Current treatment strategies depend on the clinical stage of the disease, including the extent of the primary tumour, the extent of nodal disease, and the presence of distant metastasis. With the close association of EBV infection with NPC development, EBV biomarkers have shown promise in predicting treatment outcomes. Among the omic technologies, RNA and miRNA signatures have been widely studied, showing promising results in the research setting to predict treatment response. The transformation of radiology images into measurable features has facilitated the use of radiomics to generate predictive models for better prognostication and treatment selection. Nonetheless, much of this work remains in the research realm, and challenges remain in clinical implementation.

Longitudinal post-radiotherapy plasma Epstein-Barr virus DNA trends inform on optimal risk stratification in endemic nasopharyngeal carcinoma

OBJECTIVES

To characterize longitudinal changes in Epstein-Barr virus (EBV) DNA post-radiotherapy in nasopharyngeal carcinoma (NPC) patients, and investigate whether an early (0-2 weeks) or delayed (8-12 weeks) EBV DNA result better predicts for disease-free survival (DFS).

MATERIALS AND METHODS

Histologically-confirmed NPC patients with ≥1 EBV DNA test quantified using the harmonized BamHI-W polymerase chain reaction-based assay at 0-2 and 8-12 weeks post-radiotherapy were included.

RESULTS

We identified 302 patients with EBV DNA measured at 0-2 weeks post-radiotherapy; of which, 110 (36.4 %) underwent a repeat test at 8-12 weeks post-treatment. Patients harboring a detectable EBV DNA at 0-2 weeks experienced an inferior DFS (adjusted HR1-264 copies 1.72 [95 %CI: 1.05-2.83], P = 0.031; AHR≥265 copies 4.39 [95 %CI: 1.68-11.44], P = 0.002 relative to 0 copies/mL). At 8-12 weeks, we observed substantial shifts in EBV DNA readings from 0 to 2 weeks; 76/110 (69.1 %) and 34/110 (30.9 %) patients at 0-2 weeks versus 90/110 (81.8 %) and 20/110 (18.2 %) at 8-12 weeks recorded undetectable and detectable EBV DNA, respectively. Positive EBV DNA at 8-12 weeks was strongly associated with relapse (73.3 % [11/15] for 1-264; 80.0 % [4/5] for ≥265 subgroups had relapses versus 15.6 % [14/90] for 0 copies/mL). Area under receiver operating curve values for 2-year relapse rates were 0.817 (95 %CI: 0.725-0.909) for stage + EBV DNA8-12w versus 0.654 (95 %CI: 0.542-0.765) for stage + EBV DNA0-2w. CONCLUSION: EBV DNA is dynamic post-radiotherapy, and delayed EBV DNA testing better enriched for higher-risk NPC patients. This implicates trials investigating adjuvant chemotherapy intensification based on early EBV DNA testing.

Liquid biopsy techniques and pancreatic cancer: diagnosis, monitoring, and evaluation

Pancreatic cancer (PC) is one of the most common malignancies. Surgical resection is a potential curative approach for PC, but most patients are unsuitable for operations when at the time of diagnosis. Even with surgery, some patients may still experience tumour metastasis during the operation or shortly after surgery, as precise prognosis evaluation is not always possible. If patients miss the opportunity for surgery and resort to chemotherapy, they may face the challenging issue of chemotherapy resistance. In recent years, liquid biopsy has shown promising prospects in disease diagnosis, treatment monitoring, and prognosis assessment. As a noninvasive detection method, liquid biopsy offers advantages over traditional diagnostic procedures, such as tissue biopsy, in terms of both cost-effectiveness and convenience. The information provided by liquid biopsy helps clinical practitioners understand the molecular mechanisms underlying tumour occurrence and development, enabling the formulation of more precise and personalized treatment decisions for each patient. This review introduces molecular biomarkers and detection methods in liquid biopsy for PC, including circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), noncoding RNAs (ncRNAs), and extracellular vesicles (EVs) or exosomes. Additionally, we summarize the applications of liquid biopsy in the early diagnosis, treatment response, resistance assessment, and prognostic evaluation of PC.

Early Stage and Locally Advanced Nasopharyngeal Carcinoma Treatment from Present to Future: Where Are We and Where Are We Going?

OPINION STATEMENT

Nasopharyngeal carcinoma (NPC) is a rare malignancy, endemic in China, that is commonly diagnosed in locally advanced scenarios. Its pathogenesis is strongly associated with Epstein-Barr virus (EBV), an infection for which measuring EBV plasma DNA levels has helped as a prognostic factor guiding treatment options, including a stronger treatment in those with high titers. Additionally, tobacco and alcohol are often implicated in EBV-negative patients. The local disease is treated with radiotherapy alone, preferentially intensity modulated radiotherapy. For locally advanced disease, the backbone treatment is concurrent chemoradiotherapy with the ongoing research dilemma being adding adjuvant chemotherapy or induction chemotherapy. The ongoing research is focused not only on identifying patients that will benefit from adjuvant or induction chemotherapy, but also on identifying the best chemotherapeutic regimen, regimen alternatives to diminish toxicity, the role that immune checkpoint inhibitors play, and the use of molecularly guided treatment targeting patients with NPC whether driven by EBV or tobacco and alcohol. Knowing the precise oncogenesis of NPC not only offers a better understanding of the role that EBV plays in this tumor but also helps create targeted therapies that could potentially block important pathways such as the NF-κB pathway. Much is yet to be done, but the prognosis and management of NPC patients have changed drastically, offering precise treatment methods and excellent control of the disease, even in locally advanced scenarios.

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

Background

Epstein-Barr virus (EBV) DNA quantification in nasopharyngeal cancer (NPC) is an indicator of the tumour burden, stage and survival. Although EBV dynamics in endemic regions has been extensively studied and reported, the data from non-endemic regions is sparse. This study attempts to investigate the EBV dynamics in NPC patients from a non-endemic region and also to identify the factors impacting the outcomes.

Materials and methods

This was a prospective observational study conducted at a tertiary care centre in South India and enrolled patients with non-metastatic, biopsy proven NPC, who were suitable for radical chemo-radiotherapy with or without induction chemotherapy. Two blood samples, one prior to initiation of any anticancer treatment, and second at 6 weeks post treatment, were collected to quantify EBV DNA using real-time quantitative polymerase chain reaction. Antibodies against EBV viral capsid antigen (EBV VCA IgM), EBV Early Antigen (EBV EA IgG) and EBV Nuclear Antigen (EBV EBNA IgG) were also measured in the sample. The impact of EBV dynamics on the outcomes was then analysed.

Results

The study included a total of 35 patients. Thirty-three had identifiable EBV DNA (94.3%) and a histological diagnosis of non-keratinising undifferentiated type of squamous cell carcinoma. There was no correlation between the EBV DNA and anti-EBV antibodies. There was a significant association between composite stage and pre-treatment DNA titre (p = 0.030). The mean EBV DNA titre was lower for patients with no clinically demonstrable disease at last follow-up and the reduction in EBV DNA titres was significant (p = 0.020) for those patients who remained disease free.

Conclusion

Plasma EBV DNA is an accurate and reliable biomarker for NPC for WHO type 2 and 3 tumours even in non-endemic regions.

The Promise of Circulating Tumor DNA in Head and Neck Cancer

As the seventh most common cancer globally, head and neck cancers (HNC) exert considerable disease burden, with an estimated 277,597 deaths worldwide in 2020 alone. Traditional risk factors for HNC include tobacco, alcohol, and betel nut; more recently, human papillomavirus has emerged as a distinct driver of disease. Currently, limitations of cancer screening and surveillance methods often lead to identifying HNC in more advanced stages, with associated poor outcomes. Liquid biopsies, in particular circulating tumor DNA (ctDNA), offer the potential for enhancing screening, early diagnosis, and surveillance in HNC patients, with potential improvements in HNC patient outcomes. In this review, we examine current methodologies for detecting ctDNA and highlight current research illustrating viral and non-viral ctDNA biomarker utilities in HNC screening, diagnosis, treatment response, and prognosis. We also summarize current challenges and future directions for ctDNA testing in HNC patients.

An Exploratory Study of Refining TNM-8 M1 Categories and Prognostic Subgroups Using Plasma EBV DNA for Previously Untreated De Novo Metastatic Nasopharyngeal Carcinoma

(1) Background: NPC patients with de novo distant metastasis appears to be a heterogeneous group who demonstrate a wide range of survival, as suggested by growing evidence. Nevertheless, the current 8th edition of TNM staging (TNM-8) grouping all these patients into the M1 category is not able to identify their survival differences. We sought to identify any anatomic and non-anatomic subgroups in this study. (2) Methods: Sixty-nine patients with treatment-naive de novo M1 NPC (training cohort) were prospectively recruited from 2007 to 2018. We performed univariable and multivariable analyses (UVA and MVA) to explore anatomic distant metastasis factors, which were significantly prognostic of overall survival (OS). Recursive partitioning analysis (RPA) with the incorporation of significant factors from MVA was then performed to derive a new set of RPA stage groups with OS segregation (Set 1 Anatomic-RPA stage groups); another run of MVA was performed with the addition of pre-treatment plasma EBV DNA. A second-round RPA with significant prognostic factors of OS identified in this round of MVA was performed again to derive another set of stage groups (Set 2 Prognostic-RPA stage groups). Both sets were then validated externally with an independent validation cohort of 67 patients with distant relapses of their initially non-metastatic NPC (rM1) after radical treatment. The performance of models in survival segregation was evaluated by the Akaike information criterion (AIC) and concordance index (C-index) under 1000 bootstrapping samples for the validation cohort; (3) Results: The 3-year OS and median follow-up in the training cohort were 36.0% and 17.8 months, respectively. Co-existence of liver-bone metastases was the only significant prognostic factor of OS in the first round UVA and MVA. Set 1 RPA based on anatomic factors that subdivide the M1 category into two groups: M1a (absence of co-existing liver-bone metastases; median OS 28.1 months) and M1b (co-existing liver-bone metastases; median OS 19.2 months, p = 0.023). When pre-treatment plasma EBV DNA was also added, it became the only significant prognostic factor in UVA (p = 0.001) and MVA (p = 0.015), while co-existing liver-bone metastases was only significant in UVA. Set 2 RPA with the incorporation of pre-treatment plasma EBV DNA yielded good segregation (M1a: EBV DNA ≤ 2500 copies/mL and M1b: EBV DNA > 2500 copies/mL; median OS 44.2 and 19.7 months, respectively, p < 0.001). Set 2 Prognostic-RPA groups (AIC: 228.1 [95% CI: 194.8−251.8] is superior to Set 1 Anatomic-RPA groups (AIC: 278.5 [254.6−301.2]) in the OS prediction (p < 0.001). Set 2 RPA groups (C-index 0.59 [95% CI: 0.54−0.67]) also performed better prediction agreement in the validation cohort (vs. Set 1: C-index 0.47 [95% CI: 0.41−0.53]) (p < 0.001); (4) Conclusions: Our Anatomic-RPA stage groups yielded good segregation for de novo M1 NPC, and prognostication was further improved by incorporating plasma EBV DNA. These new RPA stage groups for M1 NPC can be applied to countries/regions regardless of whether reliable and sensitive plasma EBV DNA assays are available or not.

Refining TNM-8 M1 categories with anatomic subgroups for previously untreated de novo metastatic nasopharyngeal carcinoma

PURPOSE

To propose a refined M1 classification in de novo metastatic nasopharyngeal carcinoma (NPC) based on pooled data from two academic institutions.

METHODS

Previously untreated de novo M1 NPC patients prospectively treated at The University of Hong Kong (N = 69) and Fujian Cancer Hospital (N = 114) between 2007 and 2016 were recruited and randomized in a 2:1 ratio to generate training (N = 120) and validation (N = 63) cohorts, respectively. Multivariable analysis (MVA) was performed for the training and validation cohorts to identify anatomic prognostic factors for overall survival (OS). Recursive partitioning analysis (RPA) was performed which incorporated the anatomic prognostic factors identified in the MVA to derive Anatomic-RPA groups which stratified OS in the training cohort, and were then validated in the validation cohort.

RESULTS

Median follow-up for the training and validation cohorts was 27.2 and 30.2 months with 3-year OS of 51.6% and 51.1%, respectively. MVA revealed that co-existing liver-bone metastases was the only factor prognostic for OS in both the training and validation cohorts. Anatomic-RPA separated M1 disease into M1a (no co-existing liver-bone metastases) and M1b (co-existing liver-bone metastases) with median OS 39.5 and 23.7 months, respectively (p = 0.004) in the training cohort. RPA for the validation cohort also confirmed good segregation with co-existing liver-bone metastases with median OS 47.7 and 16.0 months, respectively (p = 0.008).

CONCLUSION

Our proposal to subdivide de novo M1 NPC into M1a (no co-existing liver-bone metastases) vs. M1b (co-existing liver-bone metastases) provides better OS segregation.

Restoration of the Oral Microbiota After Surgery for Head and Neck Squamous Cell Carcinoma Is Associated With Patient Outcomes

OBJECTIVE

To evaluate the dynamics of the oral microbiome and associated patient outcomes following treatment of head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

This was a prospective cohort study at a tertiary academic center in Hong Kong SAR of patients with head and neck squamous cell carcinoma evaluating the oral microbiome in pre- and postsurgery oral rinses (at 1, 3, and 6 months) with 16S rRNA gene V3-V4 amplicon sequencing.

RESULTS

In total, 76 HNSCC patients were evaluated. There was a significantly depressed alpha diversities of oral microbial communities observed in HNSCC oral rinse samples within the first 6 months post-surgery when compared to presurgery or healthy controls. Distant clustering between pre- and postsurgery was also observed (p < 0.022). Following treatment, eight oral bacterial genera showed a trend towards the restoration in the relative abundances that approximate healthy persons. In evaluating patient outcomes, the decreased relative abundance of three periodontal bacteria (Capnocytophaga, Prevotella 7, and Leptotrichia) and the increased relative abundance of two commensal bacteria (Streptococcus and Rothia) at 6 months postsurgery compared to presurgery showed a better 3-year disease-specific survival (a cutoff of Kaplan-Meier survival curve test p < 0.3 at 36 months). In particular, the postsurgery restoration of Prevotella 7 was statistically significant in the surveyed patients (survival rate of 84% vs. 56% at 36 months, p = 0.0065).

CONCLUSIONS

Oral microbiome dysbiosis associated with HNSCC is dynamic. These dynamics of the oral microbiome postsurgery are also associated with patient treatment and outcomes and may serve as potential biomarkers for patient management in HNSCC.

Cell-Free Human Papillomavirus-DNA for Monitoring Treatment Response of Head and Neck Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

The aim of this study was to assess the value of cell-free human papillomavirus-DNA (cfHPV-DNA) as a diagnostic test for the post-treatment surveillance of patients with HPV-positive head and neck squamous cell carcinoma (HNSCC) through a systematic review and meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted in three databases (MEDLINE, Embase, and Scopus) in January 2021. The population included patients with HPV-positive HNSCC. The intervention was the use of the repeated liquid biopsy with circulating HPV-DNA detection during follow-up. The outcome was to establish the value of cfHPV-DNA as a diagnostic test for the post-treatment surveillance of patients with HPV-positive HNSCC.

RESULTS

Ten studies included in the meta-analysis provided a total of 457 patients with HPV-positive HNSCC. The meta-analytic study estimated the diagnostic performance of cfHPV-DNA as follows: pooled sensitivity and specificity of 0.65 (95% confidence interval [CI]: 0.40-0.84) and 0.99 (99% CI: 0.96-0.99), respectively; positive and negative likelihood ratios of 62.5 (99% CI: 22.9-170.2) and 0.05 (99% CI: 0.013-0.24), respectively; and pooled diagnostic odds ratio of 371.66 (99% CI: 60.4-2286.7).

CONCLUSION

Currently, the follow-up protocol for HNSCC patients includes routine clinical evaluation and radiological imaging. Biomarkers to monitor this disease are not established. Considering its high specificity, cfHPV-DNA represents a potential confirmatory test in the case of positive positron emission tomography and computed tomography. In the near future, cfHPV-DNA could be used as a biomarker for monitoring the treatment response during the clinical trials of de-escalation therapy or immunotherapy. Larger sample sizes and the homologation of study protocols and methodology are needed to better establish its utility in the clinical practice. Laryngoscope, 2021.

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.

Validation of a Highly Sensitive qPCR Assay for the Detection of Plasma Cell-Free Epstein-Barr Virus DNA in Nasopharyngeal Carcinoma Diagnosis

Quantification of plasma cell-free Epstein Barr virus DNA (cf EBV DNA) has been suggested as a promising liquid biopsy assay for screening and early detection of nasopharyngeal carcinoma (NPC). However, the diagnostic value of this assay is currently not known in the population of Vietnam, one of the countries which contributed the most to the NPC cases. Herein, we have reported a highly sensitive quantitative polymerase chain reaction (qPCR)-based assay targeting cf EBV DNA for the detection of NPC. A standard curve with linear regression, R² = 0.9961 (range: 25-150 000 copies/mL) and a detection limit of 25 copies/mL were obtained using an EBV standard panel provided by the Chinese University of Hong Kong. The clinical performance of this assay was assessed using plasma samples obtained from 261 Vietnamese individuals. The optimized qPCR assay detected cf EBV DNA in plasma with a sensitivity of 97.4% and a specificity of 98.2%. The absolute quantitative results of pretreatment cf EBV DNA and patient overall clinical stages were statistically correlated (P < .05). In summary, the remarkably high sensitivity and specificity of our optimized qPCR assay strongly supports the wide use of cf EBV DNA quantification as a routine noninvasive method in early diagnosis and management of patients with NPC.

Image-based diagnosis of residual or recurrent nasopharyngeal carcinoma may be a phantom tumor phenomenon

Some nasopharyngeal carcinoma (NPC) patients may present convincing radiological evidence mimicking residual or recurrent tumor after radiotherapy. However, by means of biopsies and long term follow-up, the radiologically diagnosed residuals/recurrences are not always what they appear to be. We report our experience on this "phantom tumor" phenomenon. This may help to avoid the unnecessary and devastating re-irradiation subsequent to the incorrect diagnosis.In this longitudinal cohort study, we collected 19 patients of image-based diagnosis of residual/recurrent NPC during the period from Feb, 2010 to Nov. 2016, and then observed them until June, 2019. They were subsequently confirmed to have no residual/recurrent lesions by histological or clinical measures. Image findings and pathological features were analyzed.Six patients showed residual tumors after completion of radiotherapy and 13 were radiologically diagnosed to have recurrences based on magnetic resonance imaging (MRI) criteria 6 to 206 months after radiotherapy. There were 3 types of image patterns: extensive recurrent skull base lesions (10/19); a persistent or residual primary lesion (3/19); lesions both in the nasopharynx and skull base (6/19). Fourteen patients had biopsy of the lesions. The histological diagnoses included necrosis/ inflammation in 10 (52.7%), granulation tissue with inflammation in 2, and reactive epithelial cell in 1. Five patients had no pathological proof and were judged to have no real recurrence/residual tumor based on the absence of detectable plasma EB virus DNA and subjective judgment. These 5 patients have remained well after an interval of 38-121 months without anti-cancer treatments.Image-based diagnosis of residual or recurrent nasopharyngeal carcinoma may be unreliable. False positivity, the "phantom tumor phenomenon", is not uncommon in post-radiotherapy MRI. This is particularly true if the images show extensive skull base involvement at 5 years or more after completion of radiotherapy. MRI findings compatible with NPC features must be treated as a real threat until proved otherwise. However, the balance between under- and over-diagnosis must be carefully sought. Without a pathological confirmation, the diagnosis of residual or recurrent NPC must be made taking into account physical examination results, endoscopic findings and Epstein-Barr virus viral load. A subjective medical judgment is needed based on clinical and laboratory data and the unique anatomic complexities of the nasopharynx.

Comparison of efficacy and safety of three induction chemotherapy regimens with gemcitabine plus cisplatin (GP), cisplatin plus fluorouracil (PF) and cisplatin plus capecitabine (PX) for locoregionally advanced previously untreated nasopharyngeal carcinoma: A pooled analysis of two prospective studies

PURPOSE

We compared, in this pooled analysis, the differences in efficacy and safety between three induction chemotherapy regimens including gemcitabine plus cisplatin (GP), cisplatin plus fluorouracil (PF) and cisplatin plus capecitabine (PX) in patients recruited into our two prospective studies for previously untreated locoregionally advanced nasopharyngeal carcinoma (NPC).

METHODS

GP, PF or PX followed by radical concurrent chemoradiotherapy was given to patients with previously untreated locoregionally advanced (stage III to IVA) NPC prospectively recruited into our two prospective studies. The study endpoints included progression-free survival (PFS) and overall survival (OS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and major acute and late treatment-related toxicities (grade ≥ 3).

RESULTS

From 2006 to 2016, 278 patients were enrolled (84, 94 and 100 patients in GP, PF and PX group respectively). After a median follow-up of 80 months, the 3-year PFS, OS, LRFS, DMFS and CSS of the whole population were 78.7%, 88.1%, 84.9%, 80.9% and 89.8%, respectively. There were no significant differences in prespecified survival endpoints among GP, PF and PX in both stage III and stage IVA patients. GP had lower incidences of severe (grade ≥ 3) anemia and diarrhea in stage III patients, as well as severe anemia, dehydration, renal impairment and vomiting in stage IVA patients. The incidences of grade ≥ 3 late toxicities were similar among these 3 induction regimens.

CONCLUSION

GP had similar efficacy and potentially fewer treatment-related complications compared with PF and PX as induction chemotherapy for previously untreated locoregionally advanced NPC.

Clinical and survival analysis of nasopharyngeal carcinoma with consistently negative Epstein-Barr virus DNA

BACKGROUND

To assess the clinical and survival features of nasopharyngeal carcinoma (NPC) with consistently negative Epstein-Barr virus (EBV) DNA level.

METHODS

Propensity score matching (PSM) method was used to create well-balanced cohorts. Kaplan-Meier method and Cox proportional hazards models were performed to conduct survival analysis.

RESULTS

Four hundred and eighty patients were enrolled. Patients with consistently negative plasma EBV DNA level had a greater chance to present a relatively earlier T and N classification compared with those with positive EBV DNA level (p < .001; p = .015). And patients with consistently negative EBV level were significantly associated with preferable 3-year DFS (95.0% vs. 84.4%, p = .004), DMFS (98.3% vs. 89.4%, p = .009), and OS (100% vs. 97.6%, p = .004).

CONCLUSIONS

NPC patients with consistently negative EBV DNA level performed an earlier clinical stage and negative EBV DNA level was related to preferable survival outcomes.

Prognostication of Half-Life Clearance of Plasma EBV DNA in Previously Untreated Non-metastatic Nasopharyngeal Carcinoma Treated With Radical Intensity-Modulated Radiation Therapy

Introduction: The prognostic role of plasma Epstein–Barr virus (EBV) DNA clearance when intensity-modulated radiotherapy (IMRT) and the 8th edition of American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) TNM Staging Classification are fully implemented remains undeciphered. We investigated if its half-life clearance during radical treatment for non-metastatic nasopharyngeal carcinoma (NPC) was an early prognosticator.

Patients and methods: Patients with previously untreated non-metastatic NPC were prospectively treated with radical IMRT and concurrent chemotherapy +/– induction/adjuvant chemotherapy from 2014 to 2018. Their plasma EBV DNA was measured immediately before treatment followed by weekly schedules until 0 copy/ml in two consecutive measurements. Cox regression models were employed to identify prognostic factors.

Results: Forty-five patients were prospectively recruited and analyzed. After a median follow-up of 30.3 months, 2 (4.5%), 1 (2.3%), and 6 (13.6%) patients experienced local, regional, and distant relapses, respectively. The median half-life clearance of plasma EBV DNA was 7.92 days. Those with half-life clearance of >15 days had a worse 3-years progression-free survival (PFS) (79.5 vs. 25.0%, p = 0.005), distant metastasis-free survival (DMFS) (85.0 vs. 31.3%, p = 0.009), and overall survival (OS) (91.3 vs. 75.0%, p = 0.024) when compared to those with a shorter half-life. Multivariable analyses demonstrated that only half-life (>15 days) was prognostic of DMFS [HR (95% CI): 4.91 (1.31; 18.39), p = 0.01] and OS [HR (95% CI): 5.24 (1.06; 26.05)] while half-life (>15 days) [HR (95% CI): 5.14 (1.28; 22.73), p = 0.02] and sum of pretreatment gross tumor volumes of the primary nasopharyngeal tumor and the radiologically positive neck nodes (GTV_P+N) [HR (95% CI): 1.01 (1.00; 1.03), p = 0.02] were prognostic of PFS.

Conclusion: The half-life clearance of plasma EBV DNA was prognostic in non-metastatic NPC staged and treated in the contemporary era. Earlier biomarker surveillance during treatment should be considered.

Clinical Trial Registration: This study has been registered with ClinicalTrials.gov (Identifier: NCT03830996).

Prognostic value of Epstein-Barr virus DNA level for nasopharyngeal carcinoma: a meta-analysis of 8128 cases

BACKGROUND

Plasma levels of Epstein-Barr virus (EBV) DNA have been employed to predict survival outcomes of patients with nasopharyngeal carcinoma (NPC). However, the prognostic value of subsequent EBV DNA levels (mid or post treatment) for NPC is needed to identify by a large cohort of patients. We performed a meta-analysis of studies including data from 8128 patients to evaluate the prognostic value of EBV DNA in NPC patients.

METHODS

We searched PubMed, Web of Science, and the Cochrane library for prospective and retrospective studies. Hazard ratios (HRs) and confidence intervals (CIs) were extracted from the studies or calculated and pooled to assess the association between EBV DNA levels pre-treatment (pre-DNA), mid-treatment (mid-DNA), and post-treatment (post-DNA) on clinical outcomes.

RESULTS

A total of 22 studies with 8128 patients was included for analysis. Pre-DNA levels predicted overall survival, progression-free survival, distant metastasis-free survival, and local-regional failure survival with HRs (95% CIs) of 2.70 (2.06, 3.54), 2.70 (2.12, 3.44), 3.49 (2.35, 5.17), and 2.00 (1.45, 2.76), respectively, and the corresponding HRs for post-DNA levels were 4.86 (3.30, 7.17), 6.29 (3.41, 11.60), 5.68 (2.71,11.93), respectively. Mid-DNA levels predicted overall survival and progression-free survival with an HR (95% CI) of 3.02 (1.54, 5.29) and 3.15 (2.05, 4.83). Subgroup analysis showed that the HR of post-DNA wasn't influenced by different detection time of post-DNA (P = 0.22, I² = 33.2%).

CONCLUSION

The EBV DNA levels have a significant prognostic impact in patients with NPC. The effect of post-treatment EBV DNA level dominated that of pre-DNA and mid-DNA levels.

Negative plasma Epstein-Barr virus DNA nasopharyngeal carcinoma in an endemic region and its influence on liquid biopsy screening programmes

BACKGROUND

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) in endemic regions may have undetectable plasma EBV DNA.

METHODS

We prospectively recruited 518 patients with non-metastatic NPC and measured their pre-treatment plasma EBV DNA. The stage distribution and prognosis between pre-treatment plasma EBV DNA-negative (0-20 copies/ml) and EBV DNA-positive (>20 copies/ml) patients following radical treatment were compared.

RESULTS

Seventy-eight patients (15.1%) were plasma EBV DNA-negative, and 62 in this subset (12.0%) had 0 copy/ml. Only 23/78 (29.5%) plasma EBV DNA-negative patients with advanced NPC (stage III-IVA) had strong EBV encoded RNA (EBER) positivity (score 3) in their tumours compared to 342/440 (77.7%) EBV DNA-positive patients of the same stages (p < 0.001). Though EBV DNA-negative patients had more early-stage disease (p < 0.001) and smaller volumes of the primary tumour and the positive neck nodes (p < 0.001), they had similar 5-year overall survival and cancer-specific survival to those EBV DNA-positive counterparts by stage. Similar results were also seen when plasma EBV DNA cut-off was set at 0 copy/ml.

CONCLUSIONS

Patients with low-volume NPC may not be identified by plasma/serum tumour markers and caution should be taken in its utility as a screening tool for NPC even in endemic regions.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT02476669.

Radiomics Model to Predict Early Progression of Nonmetastatic Nasopharyngeal Carcinoma after Intensity Modulation Radiation Therapy: A Multicenter Study

Purpose

To examine the prognostic value of a machine learning model trained with pretreatment MRI radiomic features in the assessment of patients with nonmetastatic nasopharyngeal carcinoma (NPC) who are at risk for 3-year disease progression after intensity-modulated radiation therapy and to explain the radiomics features in the model.

Materials and Methods

A total of 277 patients with nonmetastatic NPC admitted between March 2008 and December 2014 at two imaging centers were retrospectively reviewed. Patients were allocated to a discovery or validation cohort based on where they underwent MRI (discovery cohort, n = 217; validation cohort, n = 60). A total of 525 radiomics features extracted from contrast material-enhanced T1- or T2-weighted MRI studies and five clinical features were subjected to radiomic machine learning modeling to predict 3-year disease progression. Feature selection was performed by analyzing robustness to resampling, reproducibility between observers, and redundancy. Features for the final model were selected with Kaplan-Meier analysis and the log-rank test. A support vector machine was used as the classifier for the model. To interpret the pattern learned from the model, Shapley additive explanations (SHAP) was applied.

Results

The final model yielded an area under the receiver operating characteristic curve of 0.80 in both the discovery (95% bootstrap confidence interval: 0.80, 0.81) and independent validation (95% bootstrap confidence interval: 0.73, 0.89) cohorts. Analysis with SHAP revealed that tumor shape sphericity, first-order mean absolute deviation, T stage, and overall stage were important factors in 3-year disease progression.

Conclusion

These results add to the growing evidence of the role of radiomics in the assessment of NPC. By using explanatory techniques, such as SHAP, the complex interaction of features learned by the model may be understood.© RSNA, 2019Supplemental material is available for this article.

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.

Management of Nasopharyngeal Carcinoma: Is Adjuvant Therapy Needed?

Nasopharyngeal carcinoma of the undifferentiated histologic subtype is endemic and prevalent in southeast Asia. The dramatic improvement of treatment outcomes and overall prognosis during the past few decades has been attributed to advances in disease screening and diagnosis, diagnostic imaging, radiotherapy techniques, use of combination systemic therapy, and dedicated clinical and biomarker surveillance. The current practice of treating patients with advanced locoregional disease using cisplatin concurrent with conventional fractionated radiotherapy, followed by adjuvant cisplatin and fluorouracil, was established in 1998 when the landmark Intergroup-0099 Study demonstrated a survival benefit with the addition of systemic therapy.

There is little doubt regarding the need for concurrent chemotherapy, but there has been uncertainty about the magnitude of the benefit attributed to the adjuvant phase. Furthermore, instead of one-size-fits-all recommendations, it will be ideal if we can tailor adjuvant therapy to high-risk patients only to avoid unnecessary toxicities. In addition, recent evidence suggests that induction chemotherapy before concurrent chemoradiation can achieve better outcomes, especially in distant control, even in the modern era of intensity-modulated radiation therapy. This article provides a comprehensive review of key literature on the current management of locoregionally advanced nasopharyngeal carcinoma and highlights future research directions to unravel these controversies.

Optimal plasma pretreatment EBV DNA cut-off point for nasopharyngeal cancer patients treated with intensity modulated radiation therapy

Objective

Plasma Epstein-Barr virus (EBV) DNA concentration at the time of diagnosis (pre-EBV) can be used to stratify risk for nasopharyngeal cancer (NPC) patients. However, pre-EBV cut-off values vary among studies.

Methods

This was a post hoc analysis of 208 NPC patients from a phase II/III study comparing sequential (SEQ) vs. simultaneous integrated boost (SIB) intensity modulated radiation therapy. The objective was to identify the optimal pre-EBV cut-off value to predict overall survival (OS), progression free survival (PFS) and distant metastatic free survival (DMFS) rates.

Results

The pre-EBV and post-treatment EBV DNA (post-EBV) were detectable in 59.1% and 3.8% of the patients, respectively. A new pre-EBV cut-off value of 2300 copies/ml was identified by the receiver operating characteristics analysis. This cut-off value showed 82% sensitivity, 59% specificity and 31.7% positive and 93.5% negative predictive values in predicting OS. The 3-year OS, PFS and DMFS were 95.6 vs. 73.8%, 89.8 vs. 55.3% and 93 vs. 70.1% for pre-EBV < vs. ≥2300 copies/ml, respectively. Older age group (≥45 years), high pre-EBV and detectable post-EBV concentration were independent predictors for OS, PFS and DMFS in a multivariate analysis. When the stage grouping and pre-EBV value were combined, a subgroup of patients with stage II-III and pre-EBV values <2300 copies/ml. had the best survival outcomes, while the worst survival subgroup was the patients with stage III-IVb with pre-EBV values ≥2300 copies/ml.

Conclusions

Pre-EBV cut-off of 2300 copies/ml is an optimal value predicting OS, PFS and DMFS.

Prognostic Value of Plasma EBV DNA for Nasopharyngeal Cancer Patients during Treatment with Intensity-modulated Radiation Therapy and Concurrent Chemotherapy

Background

Plasma EBV DNA concentrations at the time of diagnosis (pre-EBV) and post treatment (post-EBV) have significant value for predicting the clinical outcome of nasopharyngeal cancer (NPC) patients. However, the prognostic value of the EBV concentration during radiation therapy (mid-EBV) has not been vigorously studied.

Patients and methods

This was a post hoc analysis of 105 detectable pre-EBV NPC patients from a phase II/III study comparing sequential (SEQ) versus simultaneous integrated boost (SIB) intensity-modulated radiation therapy (IMRT). Plasma EBV DNA concentrations were measured by PCR before commencement of IMRT, at the 5^th week of radiation therapy and 3 months after the completion of IMRT. The objective was to identify the prognostic value of mid-EBV to predict overall survival (OS), progression-free survival (PFS) and distant metastasis-free survival (DMFS).

Results

A median pre-EBV was 6880 copies/ml. Mid-EBV and post-EBV were detectable in 14.3% and 6.7% of the patients, respectively. The median follow-up time was 45.3 months. The 3-year OS, PFS and DMFS rates were 86.0% vs. 66.7% (p = 0.043), 81.5% vs. 52.5% (p = 0.006), 86.1% vs. 76.6% (p = 0.150), respectively, for those with undetectable mid-EBV vs. persistently detectable mid-EBV. However, in the multivariate analysis, only persistently detectable post-EBV was significantly associated with a worse OS (hazard ratio (HR) = 6.881, 95% confident interval (CI) 1.699-27.867, p = 0.007), PFS (HR = 5.117, 95% CI 1.562–16.768, p = 0.007) and DMFS (HR = 129.071, 95%CI 19.031–875.364, p < 0.001).

Conclusions

Detectable post-EBV was the most powerful adverse prognostic factor for OS, PFS and DMFS; however, detectable mid-EBV was associated with worse OS, PFS especially Local-PFS (LPFS) and may facilitate adaptive treatment during the radiation treatment period.