Quantification of Epstein–Barr virus DNA load in nasopharyngeal brushing samples in the diagnosis of nasopharyngeal carcinoma in southern China

Nasopharyngeal carcinoma (NPC) is highly incident in southern China, where 40% of world's new cases arise each year. Detection of Epstein–Barr virus (EBV) DNA load in nasopharyngeal (NP) brush/swab samples has gradually been established as a method for diagnosis of NPC. However, its applicable value in NPC diagnosis has never been investigated in southern China. It is important to explore whether such a test could be applicable to our local population. A total of 245 consecutive participants undergoing NP brushing examination were recruited to obtain the NP brushing samples in this study. Quantitative PCR assays were used to obtain the EBV DNA load. Mann–Whitney, ANOVA and receiver operating characteristic tests were used to analyze its diagnostic value. NP brushing samples from NPC patients showed extremely high levels of EBV DNA load (mean = 46360 copy/ng DNA) compared to its expression from non‐NPC control (mean = 28 copy/ng DNA) and high‐risk control (mean = 50 copy/ng DNA) groups. It produced 96% sensitivity and 97% specificity, at the COV = 225 copy/ng DNA. Furthermore, EBV DNA load could reflect disease progress. Our data showed a better performance of EBV DNA load in NP brushing samples compared with an initial biopsy, immunoglobulin A (IgA) antibody titers to viral capsid antigen in serum and EBV DNA load in plasma. Detection of EBV DNA load in NP brushing samples could be an effective supplement for NPC diagnosis. Being minimally invasive and low cost, NP brush sampling combined with EBV DNA detection demonstrates great potential for screening high‐risk populations for NPC.     

Noninvasive diagnosis of nasopharyngeal carcinoma: nasopharyngeal brushings reveal high Epstein-Barr virus DNA load and carcinoma-specific viral BARF1 mRNA

Nasopharyngeal carcinoma (NPC) is the most prevalent ENT-tumour in Indonesia. We investigated the primary diagnostic value of Epstein-Barr virus (EBV) DNA load and mRNA detection in noninvasive nasopharyngeal (NP) brushings, obtained prospectively from consecutive Indonesian ENT-patients with suspected NPC (N=106) and controls. A subsequent routine NP biopsy was taken for pathological examination and EBER-RISH, yielding 85 confirmed NPC and 21 non-NPC tumour patients. EBV DNA and human DNA load were quantified by real-time PCR. NP brushings from NPC patients contained extremely high EBV DNA loads compared to the 88 non-NPC controls (p<0.0001). Using mean EBV DNA load in controls plus 3 SD as cut-off value, specificity, sensitivity, positive and negative predictive values were 98, 90, 97 and 91%, respectively. Epstein-Barr nuclear antigen 1 (EBNA1) and the carcinoma-specific BARF1 mRNA were detected by nucleic acid sequence based amplification and found in 86 and 74% of NP brushings, confirming NPC tumour cell presence. EBV RNA positivity was even higher in fresh samples stored at -80 degrees C until RNA expression analyses (88% for both EBNA1 and BARF1). EBV RNA-negative NP brushings from proven NPC cases had the lowest EBV DNA loads, indicating erroneous sampling. No EBV mRNA was detected in NP brushings from healthy donors and non-NPC patients. In conclusion, EBV DNA load measurement combined with detection of BARF1 mRNA in simple NP brushings allows noninvasive NPC diagnosis. It reflects carcinoma-specific EBV involvement at the anatomical site of tumour development and reduces the need for invasive biopsies. This procedure may be useful for confirmatory diagnosis in large serological NPC screening programs and has potential as prognostic tool.     

Quantitative Epstein-Barr virus DNA analysis and detection of gene promoter hypermethylation in nasopharyngeal (NP) brushing samples from patients with NP carcinoma.

PURPOSE: Nasopharyngeal carcinoma (NPC) is highly prevalent in southern China and characterized by a strong association with EBV. We aimed to detect EBV DNA and cancer-related gene promoter hypermethylation in nasopharyngeal (NP) brushing samples and provide a novel noninvasive approach for NPC detection. EXPERIMENTAL DESIGN: Twenty-eight NPC cases and 26 noncancerous subjects were prospectively recruited. NP brushing samples were subjected to quantitative real-time PCR analysis of EBV DNA and methylation-specific PCR analysis of the DAP-kinase, RASSF1A, and p16 genes. RESULTS: EBV DNA quantity in NP brushing samples from NPC patients (median, 8.94 copies/actin) was significantly higher than that of controls (median, 0 copies/actin; P < 0.0001). Twenty-seven of 28 NPC patients had detectable EBV DNA in NP brushes, whereas 25 of 26 controls had undetectable or very low levels of EBV DNA. Elevated EBV DNA level in brushing samples as a tumor marker had a sensitivity of 96.4% and a specificity of 96.2% for NPC detection. Moreover, T(1) disease had a significantly lower EBV DNA level as compared with locally more advanced disease (P = 0.037). In brushing samples of NPC patients, the frequencies of DAP-kinase, RASSF1A, and p16 promoter hypermethylation were 50.0%, 39.3%, and 46.4%, respectively. Seventy-eight percent of cases showed methylation of at least one gene. No aberrant hypermethylation was detected in control samples. CONCLUSIONS: Our study demonstrated the feasibility of detecting multiple molecular tumor markers in NP brushing samples with a high sensitivity and specificity for NPC detection. It offers a powerful yet noninvasive approach for the diagnosis of NPC in high-risk populations.     

Epigenetic markers for noninvasive early detection of nasopharyngeal carcinoma by methylation‐sensitive high resolution melting

Nasopharyngeal carcinoma (NPC) is a human malignancy that is closely associated with Epstein‐Barr Virus (EBV). Early diagnosis of NPC will greatly improve the overall survival. However, current EBV DNA marker detection still lacks the predictive value to perform well in high‐risk populations for early detection of NPC. Since aberrant promoter hypermethylation of tumor suppressor genes (TSGs) is widely considered to be an important epigenetic change in early carcinogenesis, this study identified a panel of methylation markers for early detection of NPC and also assessed the clinical usefulness of these markers with noninvasive plasma specimens instead of biopsies. MS‐HRM assays were carried out to assess the methylation status of a selected panel of four TSGs (RASSF1A, WIF1, DAPK1 and RARβ2) in biopsies, NP brushings and cell‐free plasma from NPC patients. High‐risk and cancer‐free groups were used as controls. DNA methylation panel showed higher sensitivity and specificity than EBV DNA marker in cell‐free plasma from NPC patients at early Stages (I and II) and in addition to the EBV DNA marker, MS‐HRM test for plasma and NP brushing DNA methylation significantly increased the detection rate at all NPC stages as well as local recurrence, using this selected four‐gene panel (p < 0.05). MS‐HRM assay on a selected gene panel has great potential to become a noninvasive and complementary test for NPC early and recurrent detection in combination with the EBV DNA test to increase the sensitivity for NPC detection at an early stage.     

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

Epstein-Barr virus (EBV) is present within the tumor cells of most cases of nasopharyngeal carcinoma (NPC). Recent studies suggest that tumor burden is proportional to the level of EBV DNA in blood and that rapid blood testing can be used to guide therapeutic intervention. The relative utility of viral load vs. serology has been insufficiently studied. In our study, EBV viral load was measured by quantitative PCR using either real-time or end-point detection systems in serum samples from 124 NPC patients (93 pretreatment, 13 relapsed, 18 in remission) and 40 controls. Serologic titers against EBV early antigen were measured in the same serum samples. EBV DNA was detectable in 64 of 93 untreated NPC patients (69%; mean viral load 11,211 copies/ml), 11 of 13 relapsed NPC patients (85%; mean 53,039 copies/ml) and 0 of 18 remission patients. EBV DNA was detectable in only 1 of 40 non-NPC controls (3%). In 34 instances where paired plasma and serum samples were available for testing, both were effective sample types, and there was no significant difference between end-point and real-time methods for measuring viral load. Early antigen (EA) IgA and IgG titers were elevated in most NPC patients regardless of whether their disease was active or in remission. EBV viral load was more informative than was EA serology for distinguishing remission from relapsed disease. EBV DNA measurement appears to be a noninvasive way to monitor tumor burden after therapy.     

Serologic diagnosis of nasopharyngeal carcinoma. A double-blind study of four EB virus antibodies with evaluation by sequential discrimination

It is generally known that a close relationship exists between Epstein-Barr Virus (EBV) and nasopharyngeal carcinoma (NPC). Recently, patients with early lesions of NPC have been detected in the general population by use of serologic mass survey. Using the double-blind method, we have studied the diagnostic value of the four EBV antibody titers, VCA-IgA, VCA-IgG, EA-IgA and EA-IgG, in four groups of subjects, each consisting of 50 persons: patients with nasopharyngeal carcinoma (NPC group), patients with cancers other than NPC in the head and neck regions (HNC group), patients with cancers outside of head and neck regions (OC group) and normal individuals (NS group). The results of these four antibodies were evaluated both singularly and together by multivariate sequential discrimination. Taking 1:10 as the criterion of being positive, in the NPC group, the positive rate of VCA-IgA is 88%, the VCA-IgG rate is 100%, the EA-IgA rate is 48% and the EA-IgG rate is 74%. In the non-NPC group, the positive rates of VCA-IgA are as high as 86%-92%, but those of the other antibodies are as low as 0-42%. The positive rates and the geometric mean titers of these four antibodies were all elevated as compared with those in the three non-NPC groups. These differences are statistically significant. VCA-IgG is unimportant in the diagnosis of NPC because of its low specificity. By treating the antibody titers of VCA-IgA, VCA-IgG, EA-IgA and EA-IgG with sequential discrimination, the correlation rate between the serology and pathology of NPC is 88% and the false positive rate is 7.3%.     

Detecting plasma Epstein-Barr virus DNA to diagnose postradiation nasopharyngeal skull base lesions in nasopharyngeal carcinoma patients: a prospective study

The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma(NPC) is still a tough problem in clinical practice.An early and accurate diagnosis is important for subsequent management.We prospectively evaluated the diagnostic value of plasma Epstein-Barr virus(EBV) DNA in detecting postradiation nasopharyngeal skull base lesions in NPC patients.From July 2006 to September 2010,90 patients with postradiation NPC(34 women and 56 men;median age:42 years) met the selection criteria and were recruited in this study.All postradiation nasopharyngeal skull base lesions were found in the latest magnetic resonance imaging(MRI) examinations before endoscopic surgery,and the nasopharyngeal cavity was normal under flexible nasopharyngoscopy.Plasma EBV DNA detection was performed within 2 weeks before endoscopic surgery.A total of 90 endoscopic operations were successfully performed without any postoperative complications.Recurrences confirmed by postoperative pathology were found in 30 patients.The specificity,positive and negative predictive values of plasma EBV DNA detection were better than those of MRI.In addition,combining plasma EBV DNA detection with MRI improved the specificity and positive predictive values of MRI.Plasma EBV DNA detection followed by MRI would help to diagnose recurrence whereas MRI was unable.These results indicate that plasma EBV DNA is an effective and feasible biomarker for detecting postradiation nasopharyngeal skull base lesions in NPC patients.     

EA-D p45-IgG as a Potential Biomarker for Nasopharyngeal Carcinoma Diagnosis

Aim: To identify new biomarkers for NPC diagnosis with an anti-EBV Western blot test kit. Methods:Serum samples from 64 NPC patients and healthy subjects with four specific VCA-IgA/EA-IgA profiles weretested with an anti-EBV Western blot test kit from EUROIMMUN AG. Proteins were quantified with scores ofintensity visually assigned to the protein bands. The markers which showed statistical differences between theNPC and non-NPC subjects were further evaluated in another 32 NPC patients and 32 controls in comparisonwith established biomarkers including VCA-IgA, EA-IgA, EBV-related protein IgG, and EBV DNA. Results:Among the markers screened, EA-D p45-IgG showed a statistically significant difference (p < 0.05) between NPCand non-NPC subjects with VCA-IgA positivy. In 32 VCA-IgA positive NPC patients and 32 control subjects,the diagnostic accuracy of EA-D p45-IgG was 78.1% with a positive predictive value of 77.8% and a negativepredictive value of 78.6%. In the verification experiment, the specificity and sensitivity of EA-D p45-IgG were75.0% and 90.6 %, respectively. Conclusions: EA-D p45-IgG might be a potential biomarker for NPC diagnosis,especially among VCA-IgA positive subjects.     

A novel and non-invasive approach utilising nasal washings for the detection of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial cancer of the nasopharynx which is highly associated with Epstein–Barr virus (EBV). Worldwide, most of the top 20 countries with the highest incidence and mortality rates of NPC are low- and middle-income countries. Many studies had demonstrated that EBV could be detected in the tissue, serum and plasma of NPC patients. In this study, we explored the potential of assays based on non-invasive nasal washings (NW) as a diagnostic and prognostic tool for NPC. A total of 128 patients were evaluated for NW EBV DNA loads and a subset of these samples were also tested for 27 EBV and human miRNAs shortlisted from literature. EBV DNA and seven miRNAs showed area under the receiver operating characteristic curve (AUC) values of more than 0.7, suggestive of their potential utility to detect NPC. Logistic regression analyses suggested that combination of two NW assays that test for EBNA-1 and hsa-miR-21 had the best performance in detecting NPC. The trend of NW EBV DNA load matched with clinical outcome of 71.4% (10 out of 14) NPC patients being followed-up. In summary, the non-invasive NW testing panel may be particularly useful for NPC screening in remote areas where healthcare facilities and otolaryngologists are lacking, and may encourage frequent testing of individuals in the high risk groups who are reluctant to have their blood tested. However, further validation in an independent cohort is required to strengthen the utility of this testing panel as a non-invasive detection tool for NPC.     

Spontaneous remission of residual post-therapy plasma Epstein–Barr virus DNA and its prognostic implication in nasopharyngeal carcinoma: A large-scale,big-data intelligence platform-based analysis

Detectable post-therapy plasma Epstein–Barr virus (EBV) DNA predicts poor survival in non-metastatic nasopharyngeal carcinoma (NPC). However, some patients subsequently experience spontaneous remission of residual EBV DNA during follow-up and it was unclear whether these patients were still at high risk of disease failure. Using the NPC database from an established big-data intelligence platform, 3269 NPC patients who had the plasma EBV DNA load measured at the end of therapy (± 1 week) were identified. In total, 93.0% (3031/3269) and 7.0% (238/3269) of patients had undetectable and detectable (> 0 copy/ml) plasma EBV DNA at the end of therapy (EBV DNA_end), respectively. Detectable EBV DNA_end was a prognostic factor for poorer 3-year disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS), and loco-regional recurrence-free survival (LRRFS) in both univariate and multivariate analyses. Of 238 patients with residual EBV DNA_end, 192 underwent EBV DNA assay 3 months after and s pontaneous remission occurred in 72.4% (139/192). However, these patients still had poorer 3-year DFS (55.1% vs. 89.8%), OS (79.1% vs. 96.2%), DMFS (68.4% vs. 94.1%) and LRRFS (84.5% vs. 95.0%) than patients with undetectable EBV DNA_end (all p < 0.001). And patients with persistent detectable post-therapy EBV DNA had the worst outcomes. These results were confirmed in multivariate analysis. In conclusion, residual EBV DNA post therapy was a robust biomarker for NPC prognosis. Although residual post-therapy EBV DNA could spontaneous remit during follow-up, these patients were still at high risk of disease failure and such patients may benefit from adjuvant therapy.     

Hypermethylation of epithelial-cadherin gene promoter is associated with Epstein-Barr virus in nasopharyngeal carcinoma

Background: Epstein-Barr virus (EBV) is documented as the important etiologic agent of nasopharyngeal carcinoma (NPC) but the mechanism of development and pathogenesis induced by EBV is presently unclear. Hypermethylation of epithelial-cadherin (E-cadherin) promoter has been shown to be induced in NPC cell line by EBV LMP1 via DNA methyltransferase activation. EBV genomes and hypermethylation of E-cadherin promoter were investigated in NPC tissues to evaluate the role of EBV in the hypermethylation and pathogenesis of NPC. Methods: Methylation-specific polymerase chain reaction (MSP) was performed to detect E-cadherin promoter hypermethylation in paraffin embedded tissues from patients with NPC and normal nasopharyngeal tissues. EBV genomes were detected by PCR in the tissue samples. Results: Hypermethylation of E-cadherin promoter and EBV were predominantly detected in undifferentiated and non-keratinizing NPC compared to those in squamous cell NPC. Hypermethylation of E-cadherin was found in 28 of 38 (73.7%) patient samples. EBV was detected in 22 of the 28 (78.6%) NPC samples demonstrating E-cadherin hypermethylation. EBV genomes and hypermethylation were not detected in normal nasopharyngeal tissues. Significant association was found between E-cadherin hypermethylation and EBV genomes (p < 0.001; Fisher's exact test). Hypermethylation of E-cadherin was more frequently detected in advanced stages compared to those in early stages of NPC (p = 0.036; Fisher's exact test). Conclusions: The high incidence of EBV with the consistency of E-cadherin hypermethylation, particularly in undifferentiated and non-keratinizing NPC suggests the role of EBV in the hypermethylation. EBV exists at early stage of NPC that induces the hypermethylation and contributes to progression of the disease to the advanced stage of NPC.     

联合检测EB病毒不同抗体及EB病毒DNA在鼻咽癌血清学诊断中的价值

目的:评价EB病毒(EBV)抗衣壳抗原VCA-IgA抗体、抗早期抗原EA-IgA抗体、抗立即早期抗原Rta-IgG抗体和EBV-DNA检测在鼻咽癌诊断中的价值。方法:收集160例初治鼻咽癌,133例症状相似的非鼻咽癌患者和163名健康体检者的血清和血浆。采用酶联免疫法检测血清VCA-IgA、EA-IgA和Rta-IgG抗体的水平,用实时荧光定量PCR检测血浆EBV-DNA的相对含量。按鼻咽癌2008临床TNM分期法进行分期,计算不同分组、各临床分期以及鼻咽癌治疗前后的各抗体阳性率、抗体水平以及EB-DNA的检测结果并进行数据分析。结果:鼻咽癌组VCA-IgA、EA-IgA、Rta-IgG和EBV-DNA阳性率均高于鼻咽相关疾病组及健康对照组（均P<0.05）。血清VCA-IgA和EA-IgA结果相对A值（即rA或S/CO值）在Ⅰ、Ⅱ期低于Ⅲ、Ⅳ期,差异有统计学意义(P<0.05),但阳性率在各期间比较差异无统计学意义(P>0.05);Ⅰ、Ⅱ期患者Rta-IgG的rA值和阳性率明显低于Ⅲ、Ⅳ期患者(P<0.05);血浆中EBV-DNA阳性率及EBV-DNA中位数水平随着临床分期的升高而增高,Ⅰ、Ⅱ期与Ⅲ、Ⅳ期比较差异有统计学意义（P<0.05）。治疗有效（CR+ PR）患者的EBV-DNA含量明显低于治疗前水平（P<0.05）。结论:VCA-IgA、EA-IgA、Rta-IgG、EBV-DNA检测有助于鼻咽癌的辅助诊断、临床分期预测及疗效评估。     

Nasopharyngeal brush biopsies and detection of nasopharyngeal cancer in a high-risk population.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is an important tumor in many countries. Ethnic and regional factors strongly influence disease risk. NPC is usually diagnosed late in disease development, and 10-year survival rates are as low as 10%. Epstein-Barr virus (EBV), a possibly causative agent, is present in all cells of essentially all undifferentiated NPCs. We wished to determine the following: 1) whether an ambulatory nasopharyngeal brush biopsy could provide sufficient tumor cell DNA for the detection of EBV and 2) whether the detection of EBV in this locale reflects the presence of tumor cells or simply EBV carrier status. METHODS: We collected nasopharyngeal tissue via ambulatory brush biopsies from 21 patients with newly diagnosed NPC and from 157 subjects with other otolaryngologic complaints. The majority of study subjects were from high-risk populations. Sample DNA was analyzed for the presence of EBV genomic sequences by use of the polymerase chain reaction (PCR). RESULTS: Ninety-six percent of samples yielded sufficient DNA for PCR amplification. Nineteen of 21 patients with NPC brushed positive for EBV DNA, while all but two (1.3%) of 149 informative control subjects were negative for EBV (two-sided P<.0001). One of the EBV-positive control subjects had an EBV-positive inverted sinonasal papilloma; the other EBV-positive control subject exhibited no overt clinical disease. CONCLUSION: Demonstration of EBV DNA in nasopharyngeal brush biopsy specimens detects NPC with a sensitivity of at least 90% (95% confidence interval = 89.63%-91.32%) and a specificity of approximately 99% (95% confidence interval = 98.64%-98.68%). This technique merits further testing as a possible ambulatory screening strategy in high-risk populations.     

Hypermethylation of epithelial-cadherin gene promoter is associated with Epstein-Barr virus in nasopharyngeal carcinoma

Background: Epstein-Barr virus (EBV) is documented as the important etiologic agent of nasopharyngeal carcinoma (NPC) but the mechanism of development and pathogenesis induced by EBV is presently unclear. Hypermethylation of epithelial-cadherin (E-cadherin) promoter has been shown to be induced in NPC cell line by EBV LMP1 via DNA methyltransferase activation. EBV genomes and hypermethylation of E-cadherin promoter were investigated in NPC tissues to evaluate the role of EBV in the hypermethylation and pathogenesis of NPC. Methods: Methylation-specific polymerase chain reaction (MSP) was performed to detect E-cadherin promoter hypermethylation in paraffin embedded tissues from patients with NPC and normal nasopharyngeal tissues. EBV genomes were detected by PCR in the tissue samples. Results: Hypermethylation of E-cadherin promoter and EBV were predominantly detected in undifferentiated and non-keratinizing NPC compared to those in squamous cell NPC. Hypermethylation of E-cadherin was found in 28 of 38 (73.7%) patient samples. EBV was detected in 22 of the 28 (78.6%) NPC samples demonstrating E-cadherin hypermethylation. EBV genomes and hypermethylation were not detected in normal nasopharyngeal tissues. Significant association was found between E-cadherin hypermethylation and EBV genomes (p < 0.001; Fisher's exact test). Hypermethylation of E-cadherin was more frequently detected in advanced stages compared to those in early stages of NPC (p = 0.036; Fisher's exact test). Conclusions: The high incidence of EBV with the consistency of E-cadherin hypermethylation, particularly in undifferentiated and non-keratinizing NPC suggests the role of EBV in the hypermethylation. EBV exists at early stage of NPC that induces the hypermethylation and contributes to progression of the disease to the advanced stage of NPC.     

Plasma Epstein-Barr virus DNA level strongly predicts survival in metastatic/recurrent nasopharyngeal carcinoma treated with palliative chemotherapy

BACKGROUND:

Plasma Epstein‐Barr virus (EBV) DNA is widely used in screening, monitoring, and prediction of relapse in nonmetastatic nasopharyngeal carcinoma (NPC). However, data regarding utility of plasma EBV DNA in metastatic NPC are rare. The current study was to test the prognostic implication of plasma EBV DNA level in metastatic/recurrent NPC patients treated with palliative chemotherapy.

METHODS:

Plasma EBV DNA level was measured at baseline and thereafter at the start of each treatment cycle in 127 histologically proven metastatic/recurrent NPC patients treated with palliative chemotherapy. Correlations of pre‐treatment and post‐treatment plasma EBV DNA levels to survival and response were analyzed.

RESULTS:

Patients with a low pre‐treatment plasma EBV DNA level ( CONCLUSIONS: Plasma EBV DNA is of predictive value for prognosis in metastatic/recurrent NPC patients undergoing palliative chemotherapy. The pre‐treatment plasma EBV DNA level as well as the early decrease of plasma EBV DNA after chemotherapy enabled easy and early discrimination between patients who will and those who will not benefit from continued treatment. Cancer 2011. © 2011 American Cancer Society.     

Combining plasma Epstein-Barr virus DNA and nodal maximal standard uptake values of 18F-fluoro-2-deoxy-D-glucose positron emission tomography improved prognostic stratification to predict distant metastasis for locoregionally advanced nasopharyngeal carcinoma

Background

This study aimed to evaluate the value of combining the nodal maximal standard uptake values (SUVmax) of ¹⁸ F-fluoro-2-deoxy-D-glucose positron emission tomography with Epstein-Barr virus DNA(EBV DNA) levels to predict distant metastasis for nasopharyngeal carcinoma (NPC) patients

Patients and Methods

Eight hundred seventy-four patients with stage III-IVa-b NPC were evaluated for the effects of combining SUVmax and EBV DNA levels on distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS).

Results

The optimal cutoff value was 6,220 copies/mL for EBV DNA and 7.5 for SUVmax-N. Patients with lower EBV DNA levels or SUVmax-N had a significantly better 3-year DMFS, DFS, and OS. Patients were divided into four groups based on EBV DNA and SUVmax-N, as follows: low EBV DNA and low SUVmax-N (LL), low EBV DNA and high SUVmax-N (LH), high EBV DNA and low SUVmax-N (HL), and high EBV DNA and high SUVmax-N (HH). There were significant differences between the four mentioned groups in 3-year DMFS: 95.7%, 92.2%, 92.3%, and 80.1%, respectively (P^trend < 0.001). When looking at the disease stage, the 3-year DMFS in group LL, LH, HL, HH were 94.2%, 92.9%, 95.0%, and 81.1%, respectively, in stage III patients (P^trend < 0.001) and 92.7%, 87.2%, 86.3%, and 77.0% in stage IVa–b patients (P^trend = 0.026).

Conclusion

Pretreatment EBV DNA and SUVmax of neck lymph nodes were independent prognostic factors for distant metastasis in NPC patients. Combining EBV DNA and SUVmax-N led to an improved risk stratification for distant metastasis in advanced-stage disease.     

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

Saliva sampling is a non-invasive method, and could be performed by donors themselves. However, there are few studies reporting biomarkers in saliva in the diagnosis of NPC. A total of 987 salivary samples were used in this study. First, EBV DNA methylation was profiled by capture sequencing in the discovery cohort (n = 36). Second, a q-PCR based method was developed and five representative EBV DNA CpG sites (11 029 bp, 45 849 bp, 57 945 bp, 66 226 bp and 128 102 bp) were selected and quantified to obtain the methylated density in the validation cohort1 (n = 801). Third, a validation cohort2 (n = 108) was used to further verify the differences of EBV methylation in saliva. A significant increase of EBV methylation was found in NPC patients compared with controls. The methylated score of EBV genome obtained by capture sequencing could distinguish NPC from controls (sensitivity 90%, specificity 100%). Further, the methylated density of EBV DNA CpG sites revealed by q-PCR showed a good diagnostic performance. The sensitivity and specificity of detecting a single CpG site (11 029 bp) could reach 75.4% and 99.7% in the validation cohort1, and 78.2% and 100% in the validation cohort2. Besides, the methylated density of the CpG site was found to decrease below the COV in NPC patients after therapy, and increase above the COV after recurrence. Our study provides an appealing alternative for the non-invasive detection of NPC without clinical setting. It paves the way for conducting a home-based large-scale screening in the future.