Establishment of VCA and EBNA1 IgA-based combination by enzyme-linked immunosorbent assay as preferred screening method for nasopharyngeal carcinoma: a two-stage design with a preliminary performance study and a mass screening in southern China

Systematic comparison of plasma EBV DNA, anti-EBV antibodies and miRNA levels for early detection and prognosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is originated from the epithelial cells of nasopharynx, Epstein–Barr virus (EBV)‐associated and has the highest incidence and mortality rates in Southeast Asia. Late presentation is a common issue and early detection could be the key to reduce the disease burden. Sensitivity of plasma EBV DNA, an established NPC biomarker, for Stage I NPC is controversial. Most newly reported NPC biomarkers have neither been externally validated nor compared to the established ones. This causes difficulty in planning for cost‐effective early detection strategies. Our study systematically evaluated six established and four new biomarkers in NPC cases, population controls and hospital controls. We showed that BamHI‐W 76 bp remains the most sensitive plasma biomarker, with 96.7% (29/30), 96.7% (58/60) and 97.4% (226/232) sensitivity to detect Stage I, early stage and all NPC, respectively. Its specificity was 94.2% (113/120) against population controls and 90.4% (113/125) against hospital controls. Diagnostic accuracy of BamHI‐W 121 bp and ebv‐miR‐BART7‐3p were validated. Hsa‐miR‐29a‐3p and hsa‐miR‐103a‐3p were not, possibly due to lower number of advanced stage NPC cases included in this subset. Decision tree modeling suggested that combination of BamHI‐W 76 bp and VCA IgA or EA IgG may increase the specificity or sensitivity to detect NPC. EBNA1 99 bp could identify NPC patients with poor prognosis in early and advanced stage NPC. Our findings provided evidence for improvement in NPC screening strategies, covering considerations of opportunistic screening, combining biomarkers to increase sensitivity or specificity and testing biomarkers from single sampled specimen to avoid logistic problems of resampling.

What's new?

Plasma Epstein–Barr virus (EBV) DNA is an established nasopharyngeal carcinoma (NPC) biomarker, but not all cases are associated with EBV and its sensitivity for stage I NPC remains controversial. Meanwhile, most newly‐reported NPC biomarkers have neither been externally validated nor compared to established biomarkers. This study systematically evaluates six established and four new biomarkers in NPC cases, population controls, and hospital controls. The findings provide evidence to policymakers for improvement in NPC screening and monitoring strategies, covering considerations of opportunistic screening, combining biomarkers to increase sensitivity/specificity, and testing multiple biomarkers on single specimens to avoid the logistic problems of resampling.

Association Between Serum Cotinine Level and Serological Markers of Epstein-Barr Virus in Healthy Subjects in South China Where Nasopharyngeal Carcinoma Is Endemic

Introduction: Self-reported smoking has been associated with higher seropositivity for the IgA response to Epstein–Barr virus (EBV) viral capsid antigen (VCA-IgA) and transcription activator protein (Zta) in healthy men in southern China where nasopharyngeal carcinoma (NPC) is endemic. Results on the association of biochemically verified smoking status with EBV reactivation are scarce. We aimed to investigate the relations of serum cotinine level with serological markers of EBV in healthy women, in addition to men.

Methods: We collected information on demographic, lifestyle, environmental factors, and EBV serological markers in a cross-sectional study on 2,275 healthy subjects who were recruited from physical examination centers in Guangdong Province, China. In the present analysis, 901 subjects' serum cotinine levels have been measured by enzyme-linked immunosorbent assay (ELISA). Odds ratios (seropositivity of four EBV serological markers vs. seronegativity) for categorical serum cotinine levels were calculated by unconditional logistic regression with a group-specific confidence interval (CI).

Results: In women, compared with lower serum cotinine level (0–0.71 ng/ml), higher cotinine level (>0.71–1.20 ng/ml; >1.20–228.40 ng/ml) was associated but non-significantly with higher seropositivity for EBV VCA-IgA (age- and education-adjusted OR = 1.18, 95% CIs = 0.84–1.64, 1.06, 0.75–1.50). These associations remained but still non-significant after adjusting for 5-year age group, education, family history of cancer, consumption of tea, Chinese herbal tea, salted fish at childhood, and exposure to occupational dust, chemical, fume, and radiation (multivariable adjusted OR = 1.21, 95% CIs = 0.85–1.71, 1.09, 0.76–1.55). In men, compared with lower serum cotinine level (0–2.15 ng/ml), higher cotinine level (>2.15–103.6 ng/ml; >103.6–419.4 ng/ml) was significantly associated with higher seropositivity for EBV VCA-IgA and Zta-IgA (age- and education-adjusted OR = 2.16, 95% CIs = 1.37–3.41, 1.79, 1.11–2.90; 1.98, 1.17–3.34, 1.95, 1.14–3.34). The association remained significant after adjusting for potential confounders for Zta-IgA (OR = 2.32, 95% CI = 1.37–3.93 for >2.15–103.6, and 2.50, 1.43–4.38 for >103.6–419.4 ng/ml), but not for VCA-IgA (2.06, 1.29–3.27, and 1.61, 0.96–2.71).

Conclusions: Higher serum cotinine level is associated with higher seropositivity for EBV serological markers in healthy men in southern China. Such positive association was also observed in women but became non-significant. If confirmed to be causal, this finding has important implications for tobacco control and prevention of EBV-related disease, particularly for NPC.

Associations between environmental factors and serological Epstein-Barr virus antibodies in patients with nasopharyngeal carcinoma in South China

Epstein‐Barr virus (EBV) reactivation, reflected by aberrantly increased levels of various serological antibodies, has been suggested to be an early indicator of nasopharyngeal carcinoma (NPC) onset and progression. We have previously suggested that certain lifestyle and dietary factors were associated with elevated serological levels of the antibody against various EBV antigens namely VCA, Zta, EBNA1, and oral EBV DNA loads among healthy population. It remains unclear whether these potential environmental factors would also influence EBV serological antibodies in NPC patients. We conducted an epidemiological study to evaluate the associations between such environmental factors and EBV antibody levels among 1701 NPC patients in South China. Pretreatment serums were collected and examined for VCA‐IgA and EA‐IgA by immunoenzymatic assays and antienzyme rate (AER) of EBV DNase‐specific neutralizing antibody. We found that consumption of Canton‐style herbal tea was significantly correlated with increased serological antibody levels of VCA‐IgA and EA‐IgA, with adjusted ORs of 1.35 (95% CI: 1.03‐1.76) and 1.32 (95% CI: 1.01‐1.73), respectively, in the weekly intake frequency stratum, while not related to AER of EBV DNase‐specific neutralizing antibody. Smoking was found to be not only an apparent risk factor for higher antibody levels of AER in stage III‐IV patients (OR = 1.60, 95% CI: 1.11‐2.30), but also associated closely with NPC stage at diagnosis (OR = 2.17, 95% CI: 1.47‐3.22), with dose‐response effects. In conclusion, we found consumption of Canton‐style herbal tea and cigarette smoking were in positive associations with elevated EBV antibodies in NPC patients, which may be of public health significance for the primary prevention of EBV‐associated diseases especially NPC.

Is Epstein-Barr Virus Infection Associated With Thyroid Tumorigenesis?-A Southern China Cohort Study

Background: Epstein-Barr virus (EBV) is associated with many epithelial malignancies. A few reports on the association between EBV and thyroid tumorigenesis have been investigated. However, the conclusion is highly contradictory. We aimed to explore the role of EBV in thyroid nodule development and its clinical significance in a cohort from southern China.

Method: We conducted a retrospective data abstraction study of patients who underwent thyroidectomy between December 2017 and June 2018. We retrospectively analyzed the clinicopathological parameters and EBV infection status (serological antibodies and in situ hybridization).

Result: The cohort comprised 384 patients with newly diagnosed thyroid diseases, including 261 papillary thyroid carcinomas, 87 nodular goiters, 21 follicular adenomas, 12 follicular thyroid carcinomas, and 3 medullary thyroid carcinomas. Forty-two (10.9%) patients were identified as being serological antibody positive. However, there was no association between the clinicopathological parameters and serological antibody positivity. Additionally, none of the patients showed EBER expression in thyroid normal/cancer cell nuclei in in situ hybridization.

Conclusion: In this study, no correlation between EBV and thyroid diseases was found in a cohort from southern China.

A Retrospective Cohort Study of Nasopharyngeal Carcinoma Screening and Hepatocellular Carcinoma Screening in Zhongshang City

Background: Nasopharyngeal carcinoma (NPC) and hepatocellular carcinoma (HCC) have remained a major burden of public health in Southern China. The screening for early disease in asymptomatic individuals has potentially been the most promising tool to improve cancer treatment outcomes. The present study aims to evaluate the compliance rates and characteristics of cancer incidence in the population of NPC and HCC screening.

Methods: Enzyme-linked immunsorbent assay (ELISA) for Epstein-Barr virus (EBV) antibodies and Hepatitis B surface antigen (HBsAg) was performed in this population. NPC high/medium risk and HCC high risk individuals were followed-up for a number of years. The compliance rate, cancer incidence and early diagnosis rate of the screened population were statistically analyzed.

Results: (1) In the preliminary screening, the compliance rate for NPC screening was significantly higher than that for HCC screening (29.3% vs. 26.2%; P<0.05). The compliance rates for screening were positively associated with age in these two screenings (P<0.01). (2) In the NPC screening, the compliance rates for the first year follow-up among NPC high/medium risk individuals were 74.9%, which was higher than that (60.2%) for the second year follow-up (P<0.05). The compliance rates for fiberoptic endoscopy among high risk individuals decreased along with the frequency of screening (P<0.016). The rates of missed diagnosis by non-compliance and the poor diagnostic accuracy of indicators were 3.3% and 3.3%, respectively. The average annual incidence and early diagnosis rate of the compliers were higher than those of the non-compliers (94.3 per 100,000 vs. 29.0 per 100,000; P<0.05 and 77.8% vs. 18.5%; P<0.05). (3) In the preliminary HCC screening, the compliance rate for ultrasonography among high risk individuals was 61.8%. The compliance rates for the follow-up were unsatisfactory. The rates of missed diagnosis by non-compliance and the poor diagnostic accuracy of indicators were 12.3% and 24.6%, respectively. There was no significant differences in average annual incidence and the rate of early diagnosis between compliers and non-compliers (79.4 per 100,000 vs. 54.6 per 100,000, P>0.05; 49.1% vs. 38.5%, P>0.05).

Conclusion: The compliance rates for NPC and HCC screening needs to be improved. In particular, public health policies for HCC should be implemented. The present NPC screening could be the preferred strategy. However, the efficiency of HCC screening remains substantially unsatisfactory and needs to be further discussed.

Smoking can increase nasopharyngeal carcinoma risk by repeatedly reactivating Epstein-Barr Virus: An analysis of a prospective study in southern China

Background

The association between smoking and nasopharyngeal carcinoma (NPC) is still uncertain. The aim of this study was to validate smoking effect on NPC and explore if smoking can induce NPC by persistently reactivating EBV in long‐term based on a prospective cohort design.

Methods

A NPC screening cohort with 10 181 eligible residents in Sihui city, southern China was conducted from 2008 to 2015. The smoking habit was investigated through the trained interviewers and EBV antibodies (VCA‐IgA, EBNA1‐IgA) as screening markers were tested periodically. New NPC cases were identified through local cancer registry. Cox's regression model was used to estimate the adjusted hazard ratios (aHRs) of smoking on NPC incidence. In the non‐NPC participants, the associations between smoking and EBV seropositivity in different periods were assessed by logistic regression and generalized estimating equations (GEE).

Results

With a median of 7.54 years, 71 NPCs were diagnosed ≥1 year after recruitment. Compared with never smokers, the aHRs of developing NPC among ever smokers were 3.00 (95%CI: 1.46‐6.16). Stratified by sex, the HRs of ever smoking were 2.59 (95%CI: 1.07‐6.23) for male and 3.75 (95%CI: 1.25‐11.20) for female, respectively. Among the non‐NPC individuals, ever smoking was not only associated with EBV seropositivity at baseline, but also in the 3‐5 years of follow up, with adjusted odds ratios (aORs) of 1.68 (95%CI: 1.29‐2.18) for VCA‐IgA and 1.92 (95%CI: 1.42‐2.59) for EBNA1‐IgA. Among the smokers who were tested EBV antibodies at least twice, the similar results were obtained using GEE.

Conclusion

Smoking could significantly increase the long‐term risk of NPC in southern China, partly by persistently reactivating EBV.

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

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

What's new?

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

A study on the value of narrow-band imaging (NBI) for the general investigation of a high-risk population of nasopharyngeal carcinoma (NPC)

Background

This study aims to explore the feasibility of narrow-band imaging (NBI) applied for the diagnostic screening of a high-risk population of nasopharyngeal carcinoma (NPC) and increase the accuracy rate of nasopharyngeal biopsy and the diagnosis rate of early-stage patients.

Methods

The positive high-risk population of NPC to EB virus antibody was followed up. At the same time, serological screening and pharyngorhinoscopy were carried out. The specific methods were as follows: (1) all subjects received nasopharyngeal examinations through both the HD endoscopic white light mode (WL) and NBI mode, (2) nasopharyngeal biopsy was conducted on positive subjects with microscopic examination, and, finally, (3) a comparative analysis was conducted between the biopsy pathology results and microscopy results. In addition, the following comparative indicators were recorded under different modes: sensitivity, specificity, accuracy, positive likelihood ratio, and negative likelihood ratio. Then, the area under the ROC curve and the kappa coefficient were calculated.

Results

A total of 115 subjects were detected to be positive by microscopic examination under the WL mode. Among these subjects, 19 subjects were diagnosed with NPC. In addition, 24 subjects were detected to be positive by microscopic examination under the NBI mode. Among these subjects, 23 subjects were diagnosed with NPC. Under the WL mode, the specific values of the comparative indicators were as follows: sensitivity, 82.61%; specificity, 0%; and area under the ROC curve, 0.413. Furthermore, the WL mode in the diagnosis on the high-risk population of NPC exhibited poor consistency with the biopsy pathology results (kappa coefficient = − 0.069). Under the NBI mode, the specific values of the comparative indicators were as follows: sensitivity, 100%; specificity, 98.96%; and area under the ROC curve, 0.995. Furthermore, the NBI mode in the diagnosis on the high-risk population of NPC exhibited relatively satisfactory consistency with the biopsy pathology results (kappa coefficient = 0.973). Therefore, the NBI mode is significantly superior to the WL mode.

Conclusion

NBI endoscopic examinations should be conducted on a routine basis for high-risk populations of NPC. This can decrease the frequency of biopsies and enhance diagnostic effects.

Therapies based on targeting Epstein-Barr virus lytic replication for EBV-associated malignancies

In recent years, Epstein‐Barr virus (EBV) lytic infection has been shown to significantly contribute to carcinogenesis. Thus, therapies aimed at targeting the EBV lytic cycle have been developed as novel strategies for treatment of EBV‐associated malignancies. In this review, focusing on the viral lytic proteins, we describe recent advances regarding the involvement of the EBV lytic cycle in carcinogenesis. Moreover, we further discuss 2 distinct EBV lytic cycle‐targeted therapeutic strategies against EBV‐induced malignancies. One of the strategies involves inhibition of the EBV lytic cycle by natural compounds known to have anti‐EBV properties; another is to intentionally induce EBV lytic replication in combination with nucleotide analogues. Recent advances in EBV lytic‐based strategies are beginning to show promise in the treatment and/or prevention of EBV‐related tumors.

Assessment of the Long-term Diagnostic Performance of a New Serological Screening Scheme in Large-scale Nasopharyngeal Carcinoma Screening

Background: Nasopharyngeal carcinoma (NPC) remains as a major public health burden in Southern China. Over the last decade, Epstein-Barr virus (EBV) serological detection has been the most promising tool used for NPC screening. The present study aims to evaluate the long-term diagnostic performance of a new NPC screening scheme (probability of NPC units [logit P], PROB≥0.65), and compare this with other EBV seromarkers used within 2009-2015. Methods: Enzyme-linked immunosorbent assay (ELISA) for EBV capsid antigen (VCA/IgA) and nuclear antigen-1 (EBNA1/IgA) was performed in 16,712 subjects, who were within 30-59 years old.All subjects were followed up for six years. The area under the receiver operating characteristic curve (AUC) and correlation analyses were preformed to evaluate the diagnostic value of different measures. Furthermore, the rates of early diagnosis in NPC patients were statistically analyzed. Results: The new NPC screening scheme (PROB≥0.65) and the four strategies (VCA/IgA, EBNA1/IgA, VCA/IgA and EBNA1/IgA, and VCA/IgA or EBNA1/IgA) had comparable rates of early diagnosis for NPC (no significant difference was found), but the sensitivity of the new scheme (95.7%) was higher than that of the others. The top three seromarkers with the largest AUC were PROB≥0.65 (AUC:0.926, 95% CI: 0.885-0.966), VCA/IgA or EBNA1/IgA (AUC:0.883, 95% CI:0.824-0.942), and EBNA1/IgA (AUC: 0.866, 95% CI: 0.794-0.938). Conclusion: The new NPC screening scheme (PROB≥0.65) based on VCA/IgA and EBNA1/IgA outperforms the other seromarkers, and making it the preferred serodiagnostic strategy for long-term NPC screening in high-incidence areas.

EBNA1: Oncogenic Activity, Immune Evasion and Biochemical Functions Provide Targets for Novel Therapeutic Strategies against Epstein-Barr Virus- Associated Cancers

The presence of the Epstein-Barr virus (EBV)-encoded nuclear antigen-1 (EBNA1) protein in all EBV-carrying tumours constitutes a marker that distinguishes the virus-associated cancer cells from normal cells and thereby offers opportunities for targeted therapeutic intervention. EBNA1 is essential for viral genome maintenance and also for controlling viral gene expression and without EBNA1, the virus cannot persist. EBNA1 itself has been linked to cell transformation but the underlying mechanism of its oncogenic activity has been unclear. However, recent data are starting to shed light on its growth-promoting pathways, suggesting that targeting EBNA1 can have a direct growth suppressing effect. In order to carry out its tasks, EBNA1 interacts with cellular factors and these interactions are potential therapeutic targets, where the aim would be to cripple the virus and thereby rid the tumour cells of any oncogenic activity related to the virus. Another strategy to target EBNA1 is to interfere with its expression. Controlling the rate of EBNA1 synthesis is critical for the virus to maintain a sufficient level to support viral functions, while at the same time, restricting expression is equally important to prevent the immune system from detecting and destroying EBNA1-positive cells. To achieve this balance EBNA1 has evolved a unique repeat sequence of glycines and alanines that controls its own rate of mRNA translation. As the underlying molecular mechanisms for how this repeat suppresses its own rate of synthesis in cis are starting to be better understood, new therapeutic strategies are emerging that aim to modulate the translation of the EBNA1 mRNA. If translation is induced, it could increase the amount of EBNA1-derived antigenic peptides that are presented to the major histocompatibility (MHC) class I pathway and thus, make EBV-carrying cancers better targets for the immune system. If translation is further suppressed, this would provide another means to cripple the virus.

Decreased macrophage inflammatory protein (MIP)-1α and MIP-1β increase the risk of developing nasopharyngeal carcinoma

Background

The association of circulating inflammation markers with nasopharyngeal carcinoma (NPC) is still largely unclear. This study aimed to comprehensively explore the relationship between circulating cytokine levels and the subsequent risk of NPC with a two-stage epidemiologic study in southern China.

Methods

The serum levels of 33 inflammatory cytokines were first measured in a hospital-based case–control study (150 NPC patients and 150 controls) using multiplex assay platforms. Marker levels were categorized into two or more groups based on the proportion of sample measurements that was above the lower limit of detection. Odds ratios (ORs) and 95% confidence intervals (CIs) relating the serum marker concentration to the risk of NPC were computed by multivariable logistic regression models. The associations were validated in 60 patients with NPC and 120 controls in a subsequent nested case–control study within a NPC screening trial. Potential interactions between serum cytokines and Epstein–Barr virus (EBV) relating to the risk of NPC were assessed using a likelihood ratio test.

Results

The levels of serum macrophage inflammatory protein (MIP)-1α and MIP-1β in the highest categories were associated with a decreased risk of NPC in both the case–control study (MIP-1α: OR = 0.49, 95% CI = 0.26–0.95; MIP-1β: OR = 0.47, 95% CI = 0.22–1.00) and the nested case–control study (MIP-1α: OR = 0.13, 95% CI = 0.03–0.62; MIP-1β: OR = 0.20, 95% CI = 0.04–0.94), compared with those in the lowest categories. Furthermore, individuals with lower levels of these two cytokine markers who were EBV seropositive presented with a largely higher risk of NPC compared with patients with higher levels who were EBV seronegative in both the case–control study (MIP-1α: OR = 16.28, 95% CI = 7.11–37.23; MIP-1β: OR = 12.86, 95% CI = 5.9–28.05) and the nested case–control study (MIP-1α: OR = 86.12, 95% CI = 10.58–701.03; MIP-1β: OR = 115.44, 95% CI = 13.92–957.73).

Conclusions

Decreased preclinical MIP-1α and MIP-1β levels might be associated with a subsequently increased risk of NPC. More mechanistic studies are required to fully understand this finding.

Electronic supplementary material

The online version of this article (10.1186/s40880-018-0279-y) contains supplementary material, which is available to authorized users.

Establishment and validation of a two-step screening scheme for improved performance of serological screening of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), which is closely associated with Epstein-Barr virus (EBV), is one of the most prevalent cancers in southeast China. Most NPC patients are diagnosed at late stage due to inconspicuous symptoms at the early stage, and the prognosis of these patients is poor. The early diagnosis rate of NPC could be significantly increased by serological screening, but the positive predictive value (PPV) is relatively low. A simple two-step serological screening scheme was established to improve the PPV of the screening strategy and was validated by a prospective cohort. Serum antibodies specific for EBNA1, Zta, Thymidine Kinase (TK), EAD, EAR, and VCA were detected by enzyme-linked immunosorbent assay. The combination of EBNA1/IgA and VCA/IgA was used in the first step of screening, and anti-early antigens (EAs) were used in the second step of screening. EAD/IgA was the most prominent marker in the second step of screening, and other anti-EAs were complementary to EAD/IgA. As validated by a prospective cohort including 4200 participants, using the combination of EAD/IgA and TK/IgA in the second step decreased the number of high-risk participants from 128 to 27, and increased the PPV from 4.69% to 18.52%, with only one very early-stage case missed. The two-step screening scheme provides a standardized approach for NPC screening with an improved PPV and may be used in future field studies. With this two-step serological screening method, more people benefit from the screening program without increasing the need for fiberoptic endoscopy.

Anti-Epstein-Barr virus antibodies in Beijing during 2013-2017: What we have found in the different patients

Background

Epstein–Barr virus (EBV) is associated with nasopharyngeal carcinoma (NPC) which is prevalent in South China, and its association with systemic lupus erythematosus (SLE) or other autoimmune diseases has not been studied in the mainland of China. The EBV serological tests have been performed on patients with various diseases or manifestations for years at our institution and their values need to be evaluated.

Methods

For routine medical purposes, anti-EB viral capsid antigen (VCA) IgG, IgA and IgM antibodies, anti-EBV diffuse early antigen (EA-D) IgA antibodies, and anti-EBV nuclear antigen-1(EBNA-1) IgG antibodies were tested with commercial enzyme-linked immunosorbent assay (ELISA) in patients visiting Peking Union Medical College Hospital between 2013 and 2017. The test results were analyzed in this retrospective study.

Results

There were a total of 11122 serum samples available to be tested in the study. As indicators of past EBV infection, the prevalence of VCA-IgG/EBNA1-IgG were 66.6%/58.5%, 84.3%/78.8%, 92.9%/87.0% and 98.5%/95.4% in patients aged under 5 years, 6–10 years, 11–20 years and 21–30 years old, respectively, and these values maintained at this highest rate as age increased further. The prevalence of VCA-IgM, as a parameter of acute EBV infection, was 14.6%, 10.2%, 10.4%, 6.3% and 3.1% in patients aged under 5 years, 6–10 years,11–20 years, 21–30 years, 31–40 years old, respectively, and decreased to 2%~3% in older patients. Patients with elevated serum liver enzymes were more likely to have a higher prevalence of EA/D IgA antibody (P < 0.01) and young patients (≤30 years) with lymphadenopathy were more likely to have higher prevalence of VCA-IgM antibody (P < 0.01). The prevalence of VCA-IgA and EAD-IgA were 87.0% and 59.2% in NPC patients, respectively, and both were significantly higher (P < 0.001) than that in non-NPC patients. The prevalence of VCA-IgA was 45.4% and 25.6% in SLE patients and patients with other autoimmune diseases, respectively, which were significantly (P < 0.001) and mildly (P = 0.039) higher than their controls. In pediatric SLE patients between 6 and10 years old, the prevalence of VCA-IgG, VCA-IgA and EBNA1-IgG was 100%, 59.5% and 100%, respectively, all being significantly higher than the age (6-10y) related controls (P< 0.01). In the 705 cerebral spinal fluid (CSF) specimens, VCA-IgG, VCA-IgM, VCA-IgA and EAD-IgA were found to be positive in 12.1%, 0.15%, 0.25% and 0.25%, respectively. There were 157 paired specimens (CSF and serum were collected simultaneously) and VCA-IgG was identified as positive in 12.7% of the CSF and 100% of the serum specimens.

Conclusions

Around 98% of Chinese patients were infected with EBV before 30 years of age and the highest rate of acute EBV infection were observed in patients under 5 years old. EBV infection was found to be associated with elevated serum liver enzymes, NPC and SLE. Acute anti-EBV antibody was valued for young patients with lymphadenopathy but limited value for CNS neuropathy.

The Relationship Between Environmental Factors and the Profile of Epstein-Barr Virus Antibodies in the Lytic and Latent Infection Periods in Healthy Populations from Endemic and Non-Endemic Nasopharyngeal Carcinoma Areas in China

Our previous study found that smoking was associated with an elevated level of the antibody against VCA in the Epstein-Barr virus (EBV) lytic phase, which was an important predictive marker of the risk of nasopharyngeal carcinoma (NPC). It remained unknown whether environmental factors were associated with the levels of other EBV antibodies, such as Zta-IgA, EA-IgA, EBNA1-IgA, and LMP1-IgA, in the lytic and latent infection periods. We aimed to investigate the possible environmental inducers that could affect EBV antibody levels in two independent healthy male populations from endemic NPC areas in South China (N=1498) and non-endemic NPC areas in North China (N=1961). We performed ELISA and immunoenzymatic assays to test the levels of antibodies specific to the EBV antigens. The seropositive rates of antibodies against the antigens expressed in both the EBV latent and lytic infection periods, namely, LMP1-IgA, EBNA1-IgA, and Zta-IgA, in endemic areas (28.65%, 5.43% and 14.49%, respectively) were significantly higher than those in non-endemic areas (14.43%, 1.07% and 6.32%, respectively). Smoking was associated with higher seropositivity for EBNA1-IgA (OR=1.47, 95% CI=1.12-1.93) and Zta-IgA (OR=1.28, 95% CI=0.99-1.66), with dose-response effects, while not associated with the levels of LMP1-IgA. In conclusion, smoking was an important environmental factor, which associated with increased levels of EBNA1-IgA, and Zta-IgA.

Chemokine CCL27 is a novel plasma biomarker for identification the nasopharyngeal carcinoma patients from the Epstein-Barr virus capsid antigen-specific IgA seropositive population

Background

To investigate the predictive value of chemokine CCL27 for identifying early stage nasopharyngeal carcinoma (NPC) patients within a population seropositive for Epstein-Barr virus (EBV) capsid antigen-specific IgA (VCA-IgA).

Methods

CCL27 in plasma samples from 104 NPC patients, 112 VCA-IgA–positive healthy donors, and 140 VCA-IgA–negative normal subjects was measured by ELISA. Expression of CCL27 in nasopharyngeal tissue from 20 VCA-IgA–positive healthy donors and 20 NPC patients was examined by immunohistochemical staining.

Results

Levels of CCL27 in the plasma of VCA-IgA–positive healthy donors (607.33 ± 218.81 pg/ml) were significantly higher than the levels in all NPC patients (437.09 ± 217.74, P = < 0.0001) and in the subset of patients with early stage NPC (463.85 ± 226.17, P = 0.0126). Plasma CCL27 levels were significantly lower in the VCA-IgA–negative normal subjects (358.22 ± 133.15 pg/ml) than in either the VCA-IgA–positive healthy donors (P < 0.0001) or the NPC patients (P = 0.0113). CCL27 protein was detected in 16 of 20 (80%) nasopharyngeal tissue samples from VCA-IgA–positive healthy donors and in 3 of 20 (15%) tumor tissue samples from NPC patients. There was no relationship between CCL27 levels and VCA-IgA titers or plasma EBV DNA content. Receiver operating characteristic (ROC) curves demonstrated that plasma CCL27 levels had a sensitivity of 67.00%, a specificity of 73.10%, and an area under the ROC of 0.725 (95% confidence interval [CI]: 0.657–0.793) for distinguishing between NPC patients and VCA-IgA–positive healthy donors. Further analysis showed that CCL27 levels could distinguish between early stage NPC patients and VCA-IgA–positive healthy donors with an area under the ROC of 0.712 (95% CI: 0.560–0.865), a sensitivity of 59.80%, and a specificity of 84.60%.

Conclusions

Chemokine CCL27 could successfully identify NPC patients within a VCA-IgA–positive population.

Epstein-Barr virus glycoprotein gH/gL antibodies complement IgA-viral capsid antigen for diagnosis of nasopharyngeal carcinoma

To determine whether measuring antibodies against Epstein-Barr virus (EBV) glycoprotein gH/gL in serum could improve diagnostic accuracy in nasopharyngeal carcinoma (NPC) cases, gH/gL expressed in a recombinant baculovirus system was used in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies in two independent cohorts. Binary logistic regression analyses were performed using results from a training cohort (n = 406) to establish diagnostic mathematical models, which were validated in a second independent cohort (n = 279). Levels of serum gH/gL antibodies were higher in NPC patients than in healthy controls (p < 0.001). In the training cohort, the IgA-gH/gL ELISA had a sensitivity of 83.7%, specificity of 82.3% and area under the curve (AUC) of 0.893 (95% CI, 0.862-0.924) for NPC diagnosis. Furthermore, gH/gL maintained diagnostic capacity in IgA-VCA negative NPC patients (sensitivity = 78.1%, specificity = 82.3%, AUC = 0.879 [95% CI, 0.820 - 0.937]). Combining gH/gL and viral capsid antigen (VCA) detection improved diagnostic capacity as compared to individual tests alone in both the training cohort (sensitivity = 88.5%, specificity = 97%, AUC = 0.98 [95% CI, 0.97 - 0.991]), and validation cohort (sensitivity = 91.2%, specificity = 96.5%, AUC = 0.97 [95% CI, 0.951-0.988]). These findings suggest that EBV gH/gL detection complements VCA detection in the diagnosis of NPC and aids in the identification of patients with VCA-negative NPC.

Development of a population-based cancer case-control study in southern china

With its population of over 1.3 billion persons, China offers abundant opportunities to discover causes of disease. However, few rigorous population-based case-control studies have as yet been conducted in mainland China. We conducted a population-based case-control study of nasopharyngeal carcinoma in Guangdong Province and Guangxi Autonomous Region. We collected questionnaires and biospecimens from incident cases recruited between March 2010 and December 2013, and population-based controls between November 2010 and November 2014. Preparatory activities prior to subject enrollment required approximately 18 months. We enrolled a total of 2554 NPC cases and 2648 controls. Among all identified cases, 83.8% participated. For the participating cases, the median time between diagnosis and interview was 2 days. Among all contacted controls, 82.7% participated. From the enrolled cases, we collected 2518 blood specimens (provided by 98.6% of eligible cases), 2350 saliva specimens (92.0%), 2514 hair specimens (98.4%), and 2507 toenail/fingernail specimens (98.2%). From the enrolled controls, we collected 2416 blood specimens (91.2%), 2505 saliva specimens (94.6%), 2517 hair specimens (95.1%), and 2514 toenail/fingernail specimens (94.9%). We demonstrate that population-based epidemiologic research can successfully be conducted in southern China. The study protocols, databases, and biobank will serve as an extraordinarily valuable resource for testing future etiologic hypotheses.

Evaluation of seven recombinant VCA-IgA ELISA kits for the diagnosis of nasopharyngeal carcinoma in China: a case-control trial

OBJECTIVE

Seven recombinant viral capsid antigen-IgA (VCA-IgA) ELISA kits are widely used in China, but their diagnostic effects have not been evaluated. In this study, we evaluated whether the diagnostic effects of these kits are similar to those of the standard kit (EUROIMMUN, Lübeck, Germany).

METHODS

A diagnostic case-control trial was conducted with 200 cases of nasopharyngeal carcinoma (NPC) and 200 controls from NPC-endemic areas in southern China. The areas under the curve (AUCs), the sensitivities and the specificities of testing kits were compared with those of the standard kit. The test-retest reliability of each kit was determined by intraclass correlation coefficient (ICC). Their diagnostic accuracy in combination with Epstein-Barr virus nuclear antigen 1-IgA (EBNA1-IgA) was also evaluated in logistic models.

RESULTS

Three testing kits-BB, HA and KSB-showed diagnostic accuracy equal to that of the standard kit, with good performance in the AUCs (0.926-0.945), and no significant differences in sensitivity were found between early-stage and advanced-stage NPCs. ICCs exceeded 0.8. Three logistic regression models were built, and the AUCs of these models (0.961-0.977) were better than those of the individual VCA-IgA kits. All new models had diagnostic accuracy equal to that of the standard kit. New cut-off values of these three kits and their corresponding combinations for researchers to replicate and use in NPC early detection and screening in the future were provided.

CONCLUSIONS

Three recombinant VCA-IgA kits-BB,HA and KSB-had diagnostic effects equal to those of the standard kit, and, in combination with EBNA1-IgA in logistic regression models, can be used in future screening for NPC.

The Prognostic Value of Treatment-Related Lymphopenia in Nasopharyngeal Carcinoma Patients

Purpose

This study was conducted to evaluate the prognostic value of treatment-related lymphopenia in patients with nasopharyngeal carcinoma (NPC).

Materials and Methods

A total of 413 consecutive stage II-IVb NPC patients treated with concurrent chemoradiotherapy (CCRT) were enrolled. The overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were calculated with the Kaplan-Meier method, and differences were compared using the log-rank test.

Results

A minimum (mini)–absolute lymphocyte counts (ALC) of < 390 cells/μL or ALC after 3 months of CCRT (post3m-ALC) < 705 cells/μL was significantly associated with worse outcome than mini-ALC ≥ 390 cells/μL (OS, p=0.002; PFS, p=0.005; DMFS, p=0.004) or post3m-ALC ≥ 705 cells/μL (OS, p < 0.001; PFS, p < 0.001; DMFS, p=0.001). Patients with lymphopenia (mini-ALC < 390 cells/μL and post3m-ALC < 705 cells/μL) had a worse prognosis than those without lymphopenia (mini-ALC ≥ 390 cells/μL and post3m-ALC ≥ 705 cells/μL) (OS, p < 0.001; PFS, p < 0.001; DMFS, p < 0.001). Multivariate analysis revealed that post3m-ALC was an independent prognostic factor for OS (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.12 to 2.78; p=0.015), PFS (HR, 1.86; 95% CI, 1.23 to 2.82; p=0.003), and DMFS (HR, 1.87; 95% CI, 1.13 to 3.08; p=0.014). Multivariate analysis also revealed that patients with lymphopenia had a high risk of death (HR, 3.79; 95% CI, 1.75 to 8.19; p=0.001), disease progression (HR, 2.93; 95% CI, 1.59 to 5.41; p=0.001), and distant metastasis (HR, 3.89; 95% CI, 1.67 to 9.10; p=0.002). Multivariate analysis performed with time dependent Cox regression demonstrated ALC was an independent prognostic factor for OS (HR, 0.995; 95% CI, 0.991 to 0.999; p=0.025) and PFS (HR, 0.993; 95% CI, 0.988 to 0.998; p=0.006).

Conclusion

Treatment-related lymphopenia was a poor prognostic factor in NPC patients.

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.

Subtype distribution and long-term titer fluctuation patterns of serum anti-Epstein-Barr virus antibodies in a non-nasopharyngeal carcinoma population from an endemic area in South China: a cohort study

Background

Serum immunoglobulin A antibodies against Epstein–Barr virus (EBV), viral capsid antigen (VCA-IgA) and early antigen (EA-IgA), are used to screen for nasopharyngeal carcinoma (NPC) in endemic areas. However, their routine use has been questioned because of a lack of specificity. This study aimed to determine the distributions of different subtypes of antibody and to illustrate how the natural variation patterns affect the specificity of screening in non-NPC participants.

Methods

The distribution of baseline VCA-IgA was analyzed between sexes and across 10-year age groups in 18,286 non-NPC participants using Chi square tests. Fluctuations in the VCA-IgA level were assessed in 1056 non-NPC participants with at least two retests in the first 5-year period (1987–1992) after the initial screening using the Kaplan–Meier method.

Results

The titers of VCA-IgA increased with age (P < 0.001). Using a previous serological definition of high NPC risk, nasopharyngeal endoscopy and/or nasopharyngeal biopsy would be recommended in 55.5% of the non-NPC participants with an initial VCA-IgA-positive status and in 20.6% with an initial negative status during the 5-year follow-up. However, seroconversions were common; 85.2% of the participants with a VCA-IgA-positive status at baseline converted to negative, and all VCA-IgA-negative participants changed to positive at least once during the 5-year follow-up. The EA-IgA status had a high seroconversion probability (100%) from positive to negative; however, it had a low probability (19.6%) from negative to positive.

Conclusions

Age- and sex-specific cutoff titer values for serum anti-EBV antibodies as well as their specific titer fluctuation patterns should be considered when defining high NPC risk criteria for follow-up diagnostics and monitoring.

Advanced-Stage Nasopharyngeal Carcinoma: Restaging System after Neoadjuvant Chemotherapy on the Basis of MR Imaging Determines Survival

Purpose To evaluate the prognostic value of the restaging system after neoadjuvant chemotherapy (NACT) in patients with advanced-stage nasopharyngeal carcinoma (NPC). Materials and Methods This study was approved by the clinical research committee and a written informed consent was required before enrolling in the study. Prospectively enrolled were 412 consecutive patients with stage III-IVb NPC treated with NACT followed by concurrent chemotherapy and radiation therapy. Patients were staged before NACT and restaged after NACT. The progression-free survival (PFS) and distant metastasis-free survival (DMFS) were calculated with the Kaplan-Meier method, and differences were compared by using the log-rank test. Results Post-NACT T classification (PFS, P = .001) and N classification (PFS, P < .001; DMFS, P = .001) resulted in better survival curve separations than pre-NACT T classification and N classification. Patients downstaged from N2-N3 to N0-N1 disease had a better prognosis than did patients who continued to have N2-N3 diseases (3-year PFS, 83.8% vs 66.6%, P = .001; 3-year DMFS, 88.0% vs 78.4%, P = .026). Multivariate analysis revealed that post-NACT T classification (hazard ratio [HR] = 1.67; 95% confidence interval [CI]: 1.18, 2.36; P = .003) and post-NACT N classification (HR = 1.54; 95% CI: 1.17, 2.03; P = .002) were independent prognostic factors for PFS; also, post-NACT N classification (HR = 1.48; 95% CI: 1.05, 2.07; P = .025) was an independent prognostic factor for DMFS. Multivariate analysis in patients with N2-N3 disease demonstrated that the N downstaging effects of NACT was the only independent prognostic factor for PFS (HR = 0.48; 95% CI: 0.29, 0.81; P = .006) and DMFS (HR = 0.52; 95% CI: 0.28, 0.97; P = .039). Conclusion The post-NACT stage is more representative of prognosis than the pre-NACT stage in advanced-stage NPC patients, which suggests that major clinical decisions should be based on the post-NACT stage. ^© RSNA, 2016 Online supplemental material is available for this article.

The value of circulating CYFRA21-1 expression in patients with nasopharyngeal carcinoma: a study of 529 subjects

BACKGROUND

Early diagnosis of nasopharyngeal carcinoma (NPC) needs more reliable biomarkers. The aim of this study was to investigate serum cytokeratin 19 fragment 21.1 (CYFRA21-1) as an NPC biomarker based on data from a large sample.

METHODS

From October 2010 to February 2014, 529 subjects were enrolled and divided into three groups-NPC group (n = 274), healthy control group (n = 175) and nasal inflammatory disease group (n = 80). Serum CYFRA21-1 levels were measured prior to radiotherapy/chemoradiotherapy, and their associations with T, N, and clinical classification were determined. Receiver operating characteristic curve analysis was performed to discriminate the NPC group from the healthy control and nasal inflammatory disease groups. Three Epstein-Barr virus (EBV) antibodies and their correlations with serum CYFRA21-1 levels were analyzed.

RESULTS

Pretreatment serum CYFRA21-1 levels were significantly elevated in the NPC group compared with the other groups (p < 0.01), Furthermore, serum CYFRA21-1 levels decreased significantly after radiotherapy (p < 0.01). Serum CYFRA21-1 levels were closely related to T, N, and clinical classifications. The area under the curve, sensitivity and specificity of the serum CYFRA21-1 levels in the NPC patients were 0.89, 0.87 and 0.83, respectively. Strong correlations were observed between serum CYFRA21-1 levels and EBV antibodies.

CONCLUSION

Serum CYFRA21-1 may be a reliable and effective biomarker for NPC.

Survival outcome of patients with nasopharyngeal carcinoma: a nationwide analysis of 13 407 patients in Taiwan

OBJECTIVES

We reported the contemporary survival outcome of patients with nasopharyngeal carcinoma (NPC) and analysed the factors affecting survival.

DESIGN

A retrospective cohort study.

SETTING

A nationwide population-based study in Taiwan.

PARTICIPANTS

We identified 13 407 patients with newly diagnosed NPC from 2002 to 2010.

MATERIAL AND METHODS

The multivariate Cox proportional hazards model was performed to measure the mortality-association risk factor in patients with NPC after adjusting for NPC treatment and socio-demographic characteristics.

RESULTS

The 1-, 2-, 5- and 8-year overall survival (OS) rates were 89.6%, 80.4%, 65.2% and 56.5%, respectively. The factors associated with mortality risk were sex (men versus women, HR  =  1.45), age (>60 versus ≤ 40 years, HR  =  3.61), geographic region of residence (eastern Taiwan versus northern Taiwan HR   =   1.39), income (<15 840 versus >25  000, HR   =   1.87) and treatment modality (chemotherapy alone versus radiotherapy alone, HR   =   2.25).

CONCLUSION

The contemporary 5-year OS rate was 65.2% in Taiwan. Male patients, old age, residing in eastern Taiwan, low income and receiving chemotherapy alone were independent predictors for poor OS.

Prognostic Value of Plasma Epstein-Barr Virus DNA for Local and Regionally Advanced Nasopharyngeal Carcinoma Treated With Cisplatin-Based Concurrent Chemoradiotherapy in Intensity-Modulated Radiotherapy Era

This study aimed to evaluate the prognostic value of plasma Epstein-Barr Virus DNA (EBV DNA) for local and regionally advanced nasopharyngeal carcinoma (NPC) patients treated with concurrent chemoradiotherapy in intensity-modulated radiotherapy (IMRT) era.In this observational study, 404 nonmetastatic local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy were recruited. Blood samples were collected before treatment for examination of plasma EBV DNA levels. We evaluated the association of pretreatment plasma EBV DNA levels with progression-free survival rate (PFS), distant metastasis-free survival rate (DMFS), and overall survival rate (OS).Compared to patients with an EBV DNA level < 4000  copies/mL, patients with an EBV DNA ≥ 4000  copies/mL had a lower rate of 3-year PFS (76%, 95% CI [68-84]) versus (93%, 95% CI [90-96], P < 0.001), DMFS (83%, 95% CI [76-89]) versus (97%, 95% CI [94-99], P < 0.001), and OS (85%, 95% CI [78-92]) versus (98%, 95% CI [95-100], P < 0.001). Multivariate analysis showed that pretreatment EBV DNA levels (HR = 3.324, 95% CI, 1.80-6.138, P < 0.001) and clinical stage (HR = 1.878, 95% CI, 1.036-3.404, P = 0.038) were the only independent factor associated with PFS, pretreatment EBV DNA level was the only significant factor to predict DMFS (HR = 6.292, 95% CI, 2.647-14.956, P < 0.001), and pretreatment EBV DNA levels (HR = 3.753, 95% CI, 1.701-8.284, P < 0.001) and clinical stage (HR = 2.577, 95% CI, 1.252-5.050, P = 0.010) were significantly associated with OS. In subgroup analysis, higher plasma EBV DNA levels still predicted a worse PFS, DMFS, and OS for the patients stage III or stage IVa-b, compared with those with low EBV DNA levels.Elevated plasma EBV DNA was still effective prognostic biomarker for local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy. Future ramdomized clinical trials are needed to further evaluate whether plasma EBV DNA levels could be applied to guide concurrent chemotherapy regimen for local and regionally advanced NPC patients.

Expression of Serum Sialic Acid, Early Antigen-IgA, and Viral Capsid Antigen-IgA in Nasopharynx Cancer Patients: The Diagnostic Implication of Combined Assays

Background

Ebstein-Barr virus (EBV) plays a critical role in nasopharynx cancer, which can be effectively monitored by serum levels of early antigen antibody (EA-IgA) and viral capsid antigen antibody (VCA-IgA). This study explored the diagnostic value of combined assays of sialic acid (SA), EA-IgA, and VCA-IgA via the expressional assay.

Material/Methods

A total of 42 nasopharynx cancer patients and 42 benign rhinitis and healthy controls were recruited in this study. Serum EA-IgA and VCA-IgA were tested by enzyme-linked immunosorbent assay (ELISA) and enzymatic assay of serum SA. Specificity and sensitivity of those 3 assays were compared. The diagnostic value of each parameter was evaluated by ROC curves.

Results

All 3 indexes (SA, EA-IgA and VCA-IgA) showed elevated serum levels in nasopharynx cancer patients when compared to those with rhinitis, who had higher levels than healthy individuals. Concentrations of these factors were also positively correlated with the TNM staging of cancer. The sensitivity and specificity were 30.95% and 83.33% (in SA), 57.14% and 95.24% (in EA-IgA), and 76.19% and 92.86% (in VCA-IgA), respectively. VCA-IgA had the highest sensitivity among all 3 indexes. The combined assay increased the diagnostic sensitivity to 92.86% without compromising specificity.

Conclusions

SA, EA-IgA, and VCA-IgA levels were significantly elevated in nasopharynx patients’ serum. The combined assay may have clinical value in diagnosis and monitoring.

Hepatitis B virus infection and risk of nasopharyngeal carcinoma in southern China

BACKGROUND

Whether or not hepatitis B virus (HBV) infection plays a role in the development of nasopharyngeal carcinoma (NPC) is largely unknown. Our study aimed to assess the association between HBV infection and the risk of NPC in Southern China.

METHODS

We conducted a case-control study including 711 NPC cases and two groups of controls. The first control group consisted of 656 individuals with other benign tumors unrelated to HBV infection and the second group consisted of 680 healthy population controls. Multivariable ORs and corresponding 95% confidence intervals (CI) for NPC were estimated by logistic regression.

RESULTS

Patients with NPC had higher prevalence of antibodies against hepatitis B core antigen-positive [anti-HBc-(+); 47.26%] compared with either benign tumor controls (39.33%; P < 0.01) or healthy controls (41.18%; P = 0.04). In multivariable models adjusting for a set of risk factors for NPC, anti-HBc-(+) was significantly associated with a higher risk of NPC [adjusted OR (AOR), 1.40; 95% CI, 1.12-1.74 compared with the benign tumor controls and AOR, 1.48; 95% CI, 1.05-2.08 compared with the healthy controls]. The association was not modified by hepatitis B surface antigen (HBsAg) status. Finally, compared with the healthy controls, individuals with both anti-HBc-(+) and EBV antibodies had largely increased risk of NPC (AOR, 141.82; 95% CI, 68.73-292.62).

CONCLUSION

Our study suggests that HBV infection is associated with NPC risk in Southern China.

IMPACT

Prevention for HBV infection may play a role in the development of NPC.

Can Epstein-Barr virus DNA load in nasopharyngeal brushings or whole blood predict recurrent nasopharyngeal carcinoma in a non-endemic region? A prospective nationwide study of the Dutch Head and Neck Oncology Cooperative Group

This study estimated the value of quantitative measurements of EBV markers in the clinical management of nasopharyngeal carcinoma in a non-endemic area. The aim was to predict prognosis and detect recurrent and residual disease. In 72 patients, EBV DNA load in blood and nasopharyngeal brushes, and IgA VCA-p18 and EBNA1 in plasma were measured at different time points. At diagnosis and post-treatment, a cut-off value was used for detecting disease [positive (PPV) and negative (NPV) predictive value]. The markers were correlated as a continuous variable with tumor stage, disease-free survival (DFS) and overall survival (OS). The Cox hazard ratio model assessed hazard ratios. At diagnosis, the markers were above the COV in 45, 92, 85 and 83 % of the patients, respectively. Post-treatment, DNA load test in blood and brush had the best discriminating power (blood DNA load test: PPV 39 % and NPV 97 %, brush for local disease: PPV 75 % and NPV 99 %). Post-treatment, DNA load in blood was the best predictor for OS and DFS [hazard ratio 3.2 (95 % CI 1.51-3.5) and 2.3 (95 % CI 1.72-5.8)]. Assessing the EBV DNA load in blood has significant prognostic value, although the clinical value is for discussion. The EBV DNA load in the brush might improve early detection of local failures post-treatment.

Elevated high-sensitivity C-reactive protein levels predict decreased survival for nasopharyngeal carcinoma patients in the intensity-modulated radiotherapy era

Purpose

This study aimed to clarify the prognostic utility of high-sensitivity C-reactive protein (hs-CRP) in nasopharyngeal carcinoma (NPC) patients in the Intensity-Modulated Radiotherapy (IMRT) era.

Patients and Methods

In this observational study, 1,589 non-metastatic NPC patients treated with IMRT were recruited. Blood samples were collected before treatment for examination of hs-CRP levels. We evaluated the association of pretreatment hs-CRP levels with overall survival rate (OS), progression free survival rate (PFS), locoregional relapse free survival rate (LRFS) and distant metastasis free survival rate (DMFS).

Results

Baseline hs-CRP levels were correlated with sex, clinical stage, body mass index, smoking status, and EBV DNA level. Multivariate analysis showed that hs-CRP had significant association with OS (HR:1.723; 95%CI:1.238–2.398; p = 0.001), PFS (HR:1.621; 95%CI:1.273–2.064; p<0.001) and DMFS (HR:1.879; 95%CI:1.394–2.531; p<0.001). In subgroups such as advanced-stage group, low EBV DNA group and high EBV DNA group, elevated hs-CRP levels still predicted poor clinical outcomes. Furthermore, in patients with chronic HBV infection, decreased 4-year survival was observed in the cohort of high hs-CRP levels, with 87.4% vs. 94.9% (p = 0.023) for OS, 65.2% vs. 90.8% (p<0.001) for PFS, and 67.6% vs. 95.0% (p<0.001) for DMFS. A similar finding was observed for patients with cardiovascular disease, with 79.1% vs. 90.2% (p = 0.020) for PFS, and 71.4% vs. 97.6% (p = 0.002) for DMFS.

Conclusion

Elevated serum hs-CRP levels were correlated with poor survival for NPC patients in the IMRT era, playing a complementary role to TNM stage and EBV DNA. In addition, elevated hs-CRP level was still an effective indicator for patients with chronic HBV infection and cardiovascular disease.

Diagnostic significance of combined detection of Epstein-Barr virus antibodies, VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA for nasopharyngeal carcinoma

The objective of this study was to investigate the diagnostic significance of EBV antibody combined detection for nasopharyngeal carcinoma (NPC) in a high incidence region of southern China. Two hundred and eleven untreated NPC patients, 203 non-NPC ENT patients, and 210 healthy controls were recruited for the study. The titers of VCA/IgA and EA/IgA were assessed by immunoenzyme assay, and the levels of Rta/IgG and EBNA1/IgA were determined by enzyme-linked immunosorbent assay. The levels of VCA/IgA, EA/IgA, Rta/IgG and EBNA1/ IgA demonstrated no association with gender or age (p>0.05). The receiver operating characteristic curve and the area under the curve were used to evaluate the diagnostic value. The sensitivity of VCA/IgA (98.1%) and the specificity of EA/IgA (98.5%) were the highest. When a logistic regression model was used to combine the results from multiple antibodies to increase the accuracy, the combination of VCA/IgA+Rta/IgG, whose area under the curve was 0.99, had the highest diagnostic efficiency, and its sensitivity, specificity and Youden index were 94.8%, 98.0% and 0.93 respectively. The data suggest that the combination of VCA/IgA+Rta/IgG may be most suitable for NPC serodiagnosis.

Elevated levels of plasma D-dimer predict a worse outcome in patients with nasopharyngeal carcinoma

BACKGROUND

Hemostatic alterations occur during the development of cancer. Plasma D-dimer is a hypercoagulability and fibrinolytic system marker that is increased in patients with various solid tumours. The aim of this study was to evaluate the hemostatic status of nasopharyngeal carcinoma (NPC) patients by assessing plasma D-dimer levels to investigate its value as a prognostic marker.

METHODS

We retrospectively analysed 717 patients with nasopharyngeal carcinoma, and we applied Cox regression and log-rank tests to assess the association of D-dimer levels with disease-free survival (DFS), distant metastasis-free survival (DMFS), and overall survival (OS). D-dimer levels were measured using a quantitative D-dimer latex agglutination assay.

RESULTS

Using the 3rd quartile values (0.8 μg/L) as the optimal cut-offs, we found that patients with high D-dimer levels have a shorter 3-year DFS, (79%, 95%CI (73.1-84.9)) vs. (69%, 95%CI (59.2-78.8)), DMFS (87%, 95%CI (83.1-90.9)) vs. (77%, 95%CI (69.2-84.8)), and overall survival (82%, 95%CI (76.1-87.9)) vs. (76%, 95%CI (66.2-85.8)). Multivariate analysis revealed that pre-treatment D-dimer levels and EBV DNA were significant independent factors for DFS, DMFS, and OS in NPC patients. Subgroup analyses indicated that the plasma D-dimer levels could effectively stratify patient prognosis for early cancer, advanced stage cancer, and patients with EBV DNA ≥4000 copies/ml.

CONCLUSIONS

High D-dimer levels were associated with poor disease-free survival, distant metastasis-free survival, overall survival, and increased risk of mortality in NPC patients. Prospective trials are required to assess the prognostic value of D-dimer levels.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Establishment of using serum YKL-40 and SCCA in combination for the diagnosis of patients with esophageal squamous cell carcinoma

Background

Elevated serum YKL-40 levels have been observed in various cancers. We evaluated the diagnostic performance of serum YKL-40 alone or in combination with the CEA, CYFRA21-1 and SCCA tumor markers for patients with esophageal squamous cell carcinoma (ESCC).

Methods

YKL-40 was detected in ESCC cell lines and tissues by real-time RT-PCR, Western blotting and ELISA. YKL-40 protein expression was determined in 20 ESCC tumor tissues using immunohistochemistry. Serum YKL-40 was measured by ELISA in 126 healthy donors, 59 patients with benign esophageal diseases and 150 patients with ESCC. Serum CEA, CYFRA21-1 and SCCA were determined by electrochemiluminescence.

Results

YKL-40 mRNA and protein were observed in ESCC cancer cell lines, tissues and cell culture media, respectively. YKL-40 expression was observed in 17 of 20 ESCC samples (85%). Serum YKL-40 concentration was significantly elevated in patients with ESCC (Range: 6.95-502.10 ng/ml) compared with patients with benign diseases (Range: 1.21-429.30 ng/ml; P = 0.038) and healthy controls (Range: 2.56-132.26 ng/ml; P < 0.001). ROC curves demonstrated that serum YKL-40 has a sensitivity of 72.70%, a specificity of 84.13% and an AUC of 0.874 for the diagnosis of ESCC, which was superior to CEA (Sen: 8.00%; Spe: 96.80%, AUC = 0.652), CYFRA21-1 (Sen: 40.00%; Spe: 92.06%, AUC = 0.746) and SCCA (Sen: 32.67%; Spe: 94.44%, AUC = 0.789). The YKL-40 and SCCA combination was better for diagnosing ESCC (Sen: 82.00%, Spe: 79.37%, PPV: 82.55 and NPV: 78.74; AUC = 0.917) than the YKL-40 and CEA combination (Sen: 74.00%, Spe: 83.20%, PPV: 84.09 and NPV: 72.73; AUC = 0.877), the YKL-40 and CYFRA21-1 combination (Sen: 82.00%, Spe: 77.78%, PPV: 81.46% and NPV: 78.40%; AUC = 0.897) or the CEA, CYFRA21-1 and SCCA combination (Sen: 56.67%, Spe: 84.80%, PPV: 81.73 and NPV: 61.99; AUC = 0.831). Associations between serum YKL-40 levels and the clinic characteristics of ESCC were not significant, with the exception of age (p = 0.001).

Conclusions

ESCC tumor cells and tissues express YKL-40. Serum YKL-40 may be a potential biomarker for ESCC. Serum YKL-40 in combination with SCCA significantly increases the sensitivity of detecting ESCC.

Evaluation of a semi-quantitative ELISA for IgA antibody against Epstein-Barr virus capsid antigen in the serological diagnosis of nasopharyngeal carcinoma

OBJECTIVES

This study was designed to establish an ELISA method, as well as the cut-off value, for IgA against Epstein-Barr virus (EBV) viral capsid antigen (VCA), as a screening assay for nasopharyngeal carcinoma (NPC) in southern China. In addition, the correlation between relative optical density (rOD) values from ELISA and titers from the immunoenzymatic assay (IEA) was also evaluated.

METHODS

Two hundred and fifty-eight NPC cases, 33 non-NPC head and neck cancer patients, and 1156 healthy controls were recruited for this study. VCA-IgA and early antigen (EA)-IgA were measured by ELISA kits and IEA in parallel.

RESULTS

The total precision of the VCA-IgA ELISA achieved a level of <13.0% coefficient of variation. An rOD value of 1.60 for the VCA-IgA ELISA was determined as the cut-off point for southern China, and the sensitivity and specificity for NPC diagnosis when using this cut-off value were 93.0% and 92.4%, respectively. The area under the receiver operating characteristic curve (ROC-AUC) value was 0.969. The correlation coefficient between titers and rOD values was 0.957. rOD values were correlated with NPC overall stage and lymph node involvement.

CONCLUSIONS

The cut-off level established in our study could be used to facilitate more accurate diagnosis of NPC in southern China. The rOD value might be an index for NPC prognosis, since it shows a good correlation with the titer from IEA.

Epstein-Barr virus serology as a potential screening marker for nasopharyngeal carcinoma among high-risk individuals from multiplex families in Taiwan

BACKGROUND

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated cancer that is highly treatable when diagnosed early, with 5-year disease-free survival of approximately 90%. However, NPC is typically diagnosed at advanced stages, in which disease-free survival is <50%. There is, therefore, a need for clinical tools to assist in early NPC detection, particularly among high-risk individuals.

METHODS

We evaluated the ability of anti-EBV IgA antibodies to detect incident NPC among high-risk Taiwanese individuals. NPC cases (N = 21) and age- and sex-matched controls (N = 84) were selected. Serum collected before NPC diagnosis was tested for ELISA-based IgA antibodies against the following EBV peptides: EBNA1, VCAp18, EAp138, Ead_p47, and VCAp18 + EBNA1 peptide mixture. The sensitivity, specificity, and screening program parameters were calculated.

RESULTS

EBNA1 IgA had the best performance characteristics. At an optimized threshold value, EBNA1 IgA measured at baseline identified 80% of the high-risk individuals who developed NPC during follow-up (80% sensitivity). However, approximately 40% of high-risk individuals who did not develop NPC also tested positive (false positives). Application of EBNA1 IgA as a biomarker to detect incident NPC in a previously unscreened, high-risk population revealed that 164 individuals needed to be screened to detect 1 NPC and that 69 individuals tested positive per case detected.

CONCLUSIONS

EBNA1 IgA proved to be a sensitive biomarker for identifying incident NPC, but future work is warranted to develop more specific screening tools to decrease the number of false positives.

IMPACT

Results from this study could inform decisions about screening biomarkers and referral thresholds for future NPC early-detection program evaluations.

Trans-Oral Brush Biopsies and Quantitative PCR for EBV DNA Detection and Screening of Nasopharyngeal Carcinoma

Objectives

To evaluate a newly developed noninvasive ambulatory, quantitative polymerase chain reaction (Q-PCR) Epstein-Barr virus (EBV) DNA detection and screening system (NP Screen™) for nasopharyngeal carcinoma (NPC).

Study Design

Correlation of the nasopharyngeal epithelial EBV-DNA levels and clinical findings by nasopharyngoscopy and final pathologic diagnosis of NPC with biopsy.

Setting

Multicenter ENT/Oncology clinics in Hong Kong (Radiation Oncology Clinic at the Queen Elizabeth Hospital and Radiation Oncology Clinic and Head and Neck Clinic, Queen Mary Hospital, University of Hong Kong) and in Toronto, Canada (the Otolaryngology-Head and Neck Clinic at the Rouge Valley Health System and 2 large ENT practices in Toronto).

Methods

A single-use trans-oral brush was used for rapid, nontraumatic nasopharyngeal (NP) epithelial cells DNA harvest in 600 Chinese patients, combined with a preservation and shipping kit for remote, real-time Q-PCR EBV DNA determinations.

Results

All 600 patients had NP brushings using NP Screen in an ambulatory environment, and no adverse events or complications were recorded. A final 578 patients were included with sufficient amount of DNA for completion of the Q-PCR assay. Of these 578 patients, 94 were confirmed positive for NPC histologically. The study yielded a sensitivity of 98.9%, specificity of 99.3%, positive predictive value (PPV) of 96.9%, and negative predictive value (NPP) of 99.7% for NP Screen in detecting NPC. Endoscopy had a sensitivity of 94%, specificity 97.1%, PPV 85%, and NPP 98.9%.

Conclusions

The trans-oral brushing system fulfills the characteristics of a noninvasive, sensitive, specific detection method suitable for routine, large-scale ambulatory NPC risk assessment for high-risk NPC populations.

Evaluation of plasma Epstein-Barr virus DNA load to distinguish nasopharyngeal carcinoma patients from healthy high-risk populations in Southern China

BACKGROUND

The utility of circulating Epstein-Barr Virus (EBV) DNA as a tumor marker for nasopharyngeal carcinoma (NPC) detection suggests that it might improve the diagnostic performance of anti-EBV antibody markers in NPC screening. In this study, the authors evaluated whether circulating EBV DNA load is capable of distinguishing NPC patients from high-risk individuals who have positive anti-EBV antibodies.

METHODS

In a population-based NPC screening trial in Sihui City and Zhongshan City, Guangdong Province, China, the authors previously identified 862 high-risk participants with 2 screening markers, immunoglobulin A (IgA) antibodies to EBV capsid antigen (VCA/IgA) and nuclear antigen-1 (EBNA1/IgA). In the current study, real-time polymerase chain reaction was used to measure the baseline plasma EBV DNA load among 825 participants (97%). Follow-up was extended to the end of 2011 to evaluate the diagnostic and predictive values of plasma EBV DNA load.

RESULTS

By using 0 copies/mL as the cutoff value, plasma EBV DNA had a sensitivity of 86.8% (33 of 38 patients) for NPC detected within the first year of follow-up, yielding a positive predictive value of 30% (33 of 110 participants) and a negative predictive value of 99.3% (696 of 701 participants). The patients who had early stage NPC had lower sensitivity (81.5%; 22 of 27 patients) than those who had advanced NPC (100%; 11 of 11 patients). For the 14 patients who had NPC detected after 1 year of follow-up, only 50% (7 of 14 patients) tested positive for EBV DNA at baseline.

CONCLUSIONS

The plasma EBV DNA load may improve the accuracy of diagnosing NPC in high-risk individuals, but it appears to have limited value in screening patients who have early stage NPC and predicting NPC development.

Systematic review and meta-analysis of the sero-epidemiological association between Epstein-Barr virus and systemic lupus erythematosus

INTRODUCTION

Infection with Epstein-Barr virus (EBV) has been suggested to contribute to the pathogenesis of systemic lupus erythematosus (SLE). We sought to determine whether prior infection with the virus occurs more frequently in patients with SLE compared to matched controls.

METHODS

We performed a systematic review and meta-analyses of studies that reported the prevalence of anti-EBV antibodies in the sera from cases of SLE and controls by searching Medline and Embase databases from 1966 to 2012, with no language restriction. Mantel-Haenszel odds ratios (OR) for the detection of anti-EBV antibodies were calculated, and meta-analyses conducted. Quality assessments were performed using a modified version of the Newcastle-Ottawa scale.

RESULTS

Twenty-five case-control studies were included. Quality assessment found most studies reported acceptable selection criteria but poor description of how cases and controls were recruited. There was a statistically significant higher seroprevalence of anti-viral capsid antigen (VCA) IgG (OR 2.08; 95% confidence interval (CI) 1.15 - 3.76, p = 0.007) but not anti-EBV-nuclear antigen1 (EBNA1) (OR 1.45; 95% CI 0.7 to 2.98, p = 0.32) in cases compared to controls. The meta-analyses for anti-early antigen (EA) /D IgG and anti-VCA IgA also showed significantly high ORs (4.5; 95% CI 3.00 to 11.06, p < 0.00001 and 5.05 (95% CI 1.95 - 13.13), p = 0.0009 respectively). However, funnel plot examination suggested publication bias.

CONCLUSIONS

Overall, our findings support the hypothesis that infection with EBV predisposes to the development of SLE. However, publication bias cannot be excluded and the methodological conduct of studies could be improved, with regard to recruitment, matching and reporting of blinded laboratory analyses.

Nasopharyngeal carcinoma incidence and mortality in China in 2009

Nasopharyngeal carcinoma (NPC) is rare globally but common in China and exhibits a distinct ethnic and geographic distribution. In 2009, the National Central Cancer Registry in China provided real-time surveillance information on NPC. Individual NPC cases were retrieved from the national database based on the ICD-10 topography code C11. The crude incidence and mortality of NPC were calculated by sex and location (urban/rural). China's population in 1982 and Segi's world population structures were used to determine age-standardized rates. In regions covered by the cancer registries in 2009, the crude incidence of NPC was 3.61/100,000 (5.08/100,000 in males and 2.10/100,000 in females; 4.19/100,000 in urban areas and 2.42/100,000 in rural areas). Age-standardized incidences by Chinese population (ASIC) and Segi's world population (ASIW) were 2.05/100,000 and 2.54/100,000, respectively. The crude mortality of NPC was 1.99/100,000 (2.82/100,000 in males and 1.14/100,000 in females; 2.30/100,000 in urban areas and 1.37/100,000 in rural areas). The age-standardized mortalities by Chinese population (ASMC) and world population (ASMW) were 1.04/100,000 and 1.35/100,000, respectively. The incidence and mortality of NPC were higher in males than in females and higher in urban areas than in rural areas. Both age-specific incidence and mortality were relatively low in persons younger than 30 years old, but these rates dramatically increased. Incidence peaked in the 60-64 age group and mortality peaked in the over 85 age group. Primary and secondary prevention, such as lifestyle changes and early detection, should be carried out in males and females older than 30 years of age.

Two Epstein-Barr virus-related serologic antibody tests in nasopharyngeal carcinoma screening: results from the initial phase of a cluster randomized controlled trial in Southern China

A nasopharyngeal carcinoma (NPC) mass screening trial using a combination of immunoglobulin A antibodies to Epstein-Barr virus capsid antigen and nuclear antigen-1 by enzyme-linked immunosorbent assay in addition to indirect mirror examination in the nasopharynx and/or lymphatic palpation (IMLP) was conducted in southern China. Cantonese aged 30-59 years residing in 2 cities randomly selected by cluster sampling, Sihui and Zhongshan, were invited to participate in this screening from May 2008 through May 2010. Participants were offered fiberoptic endoscopy examination and/or pathologic biopsy if their serologic tests reached our predefined level of high risk or if results from the physical examination indicated possible cancer (i.e., were IMLP positive). A total of 28,688 individuals were voluntarily screened in the initial round. The overall NPC detection rate was 0.14% (41/28,688) with an early diagnosis rate of 68.3% (28/41) during the first year of follow-up. Thirty-eight of 41 cases (92.7%) were detected among the high-risk group, and 7 of 41 cases (17.1%) were detected among the IMLP-positive group. The 2 Epstein-Barr virus serologic tests by enzyme-linked immunosorbent assay could be a feasible alternative for NPC screening in endemic areas. Further follow-up is needed to examine whether screening has an effect on decreasing mortality from NPC in these areas.

Invited commentary: Epstein-Barr virus-based screening for the early detection of nasopharyngeal carcinoma: a new frontier

Approximately 2 million new cases of cancer are caused by infections each year. For many of these cancers, we have been successful at developing methods for prevention or effective treatment/control. Epstein-Barr virus (EBV), a ubiquitous infection that establishes lifelong latency, was the first infection to be linked to the development of cancers, including nasopharyngeal carcinoma, lymphomas, and gastric cancer. EBV infection is linked to the development of approximately 200,000 new cancers each year, yet there have been no successful efforts to implement EBV-based strategies for the reduction in the burden of EBV-associated cancers. In this issue of the Journal, Liu et al. (Am J Epidemiol. 2013;177(3):242-250) report results from the enrollment phase of a large effort to demonstrate the efficacy of an EBV-based screening strategy to detect nasopharyngeal carcinoma at early stages and hopefully reduce the mortality associated with this disease. In this invited commentary, the design and initial findings from this demonstration project are reviewed, possible ways to enrich the effort are discussed, and populations that might benefit from EBV-based screening in the future are identified.

Characterization of ELISA detection of broad-spectrum anti-Epstein-Barr virus antibodies associated with nasopharyngeal carcinoma

Epstein-Barr virus (EBV) infection is associated with undifferentiated nasopharyngeal carcinomas (NPC). A distinct seroreactivity pattern to EBV is predictive of subsequent risk of sporadic and familial nasopharyngeal carcinomas. There are currently no accepted screening tools for guiding the clinical management of individuals at high-risk for nasopharyngeal carcinomas, particularly unaffected relatives from nasopharyngeal carcinoma multiplex families. Therefore, the reproducibility of a panel of largely synthetic peptide-based anti-EBV antibody ELISAs was evaluated and their ability to distinguish nasopharyngeal carcinoma cases from controls was explored. IgG and IgA antibodies against 6 different EBV antigens (10 assays, total) were tested on sera from 97 individuals representing the full spectrum of anti-EBV seroprevalence (i.e., healthy individuals with no known EBV seroreactivity, healthy individuals with known EBV seroreactivity, and nasopharyngeal carcinoma cases). Each specimen was tested in triplicate to assess within-batch and across-batch variation, and the triplicate testing was repeated on two separate days. Reproducibility was assessed by the coefficients of variation (CVs) and intraclass correlation coefficients (ICCs). All markers were detectable in 17% or more of samples. For all but one marker, the overall, within-batch, and across-batch CVs were below 15%, and the ICCs were above 70% for all but three markers. Sensitivity of these markers to detect prevalent nasopharyngeal carcinomas ranged from 22% to 100%, and among unaffected controls, most distinguished those with and without known seropositivity. In conclusion, a large number of EBV markers can be measured reliably in serum samples using peptide-based anti-EBV ELISAs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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