Association of Epstein-Barr virus with nasopharyngeal carcinoma in Alaskan native patients: serum antibodies and tissue EBNA and DNA

Development of a Duplex Serological Multiplex Assay for the Simultaneous Detection of Epstein-Barr Virus IgA and IgG Antibodies in Nasopharyngeal Carcinoma Patients

Epstein-Barr virus (EBV) IgA and IgG antibodies in serum from nasopharyngeal carcinoma (NPC) patients are well-established markers for EBV-positive NPC. Luminex-based multiplex serology can analyze antibodies to multiple antigens simultaneously; however, the detection of both IgA and IgG antibodies requires separate measurements. Here we describe the development and validation of a novel duplex multiplex serology assay, which can analyze IgA and IgG antibodies against several antigens simultaneously. Secondary antibody/dye combinations, as well as serum dilution factors, were optimized, and 98 NPC cases matched to 142 controls from the Head and Neck 5000 study (HN5000) were assessed and compared to data previously generated in separate IgA and IgG multiplex assays. EBER in situ hybridization (EBER-ISH) data available for 41 tumors was used to calibrate antigen-specific cut-offs using receiver operating characteristic (ROC) analysis with a prespecified specificity of ≥90%. A directly R-Phycoerythrin-labeled IgG antibody in combination with a biotinylated IgA antibody and streptavidin-BV421 reporter conjugate was able to quantify both IgA and IgG antibodies in a duplex reaction in a 1:1000 serum dilution. The combined assessment of IgA and IgG antibodies in NPC cases and controls from the HN5000 study yielded similar sensitivities as the separate IgA and IgG multiplex assays (all > 90%), and the duplex serological multiplex assay was able to unequivocally define the EBV-positive NPC cases (AUC = 1). In conclusion, the simultaneous detection of IgA and IgG antibodies provides an alternative for the separate IgA/IgG antibody quantification and may present a promising approach for larger NPC screening studies in NPC endemic areas.

The Alaska Native Tumour Registry: fifty years of cancer surveillance data for Alaska Native people

Like other Indigenous Circumpolar populations, Alaska Native (AN) people experience different patterns of cancer than their non-Indigenous counterparts. Every 5 years, the Alaska Native Tumour Registry releases a comprehensive report on cancer among AN people; this study provides 50 years of cancer surveillance data. Five-year annual-average age-adjusted incidence rates were calculated for time-periods ranging 1969-2018. AN data were compared with data for US whites (SEER 9). Mortality rates were calculated for 1994-2018 using data from the National Center for Health Statistics. During 2014-2018, there were 2,401 cases of invasive cancer among AN people. Among these, the most commonly diagnosed cancers were colorectal (405 cases, 17% of all cancers), lung and bronchus (373 cases, 16% of all cancers), and female breast (340 cases, 14% of all cancers). Lung cancer was the leading cause of cancer death, followed by colorectal and female breast cancers. These leading cancers are screenable, and preventable through lifestyle modifications including tobacco cessation, healthy eating and engaging in physical activity. These data provide important information to support cancer prevention and control among AN people. Cancer surveillance has been a valuable tool throughout the Circumpolar North to support reducing the burden of cancer among Indigenous populations.Abbreviations: ANAI: Alaska Native/American Indian; AN: Alaska Native; USW: U.S. White(s); ANMC: Alaska Native Medical Center; ANTR: Alaska Native Tumour Registry; IR: Incidence Rate; CI: Confidence Interval; RR: Rate Ratio; ICD-O-3: International Classification of Diseases for Oncology - Third Edition; SEER: Surveillance, Epidemiology and End Results.

Nasopharyngeal carcinoma patients from Norway show elevated Epstein-Barr virus IgA and IgG antibodies prior to diagnosis

BACKGROUND

IgA antibodies against few Epstein-Barr virus (EBV) proteins are established serological markers for nasopharyngeal carcinoma (NPC). We recently validated a novel, comprehensive EBV marker panel and showed that IgA, but also IgG antibodies against multiple EBV proteins are highly sensitive and specific for EBV-positive NPC at diagnosis. However, data about these novel biomarkers as prospective markers for NPC are sparse.

METHODS

This study included 30 incident NPC cases and 60 matched controls from the Norwegian Janus Serum Bank. For 21 NPCs, molecular EBV and human papillomavirus (HPV) status were assessed by EBER-ISH and HPV DNA/RNA testing by PCR, respectively. IgA and IgG serum antibodies against 17 EBV antigens were analyzed in prediagnostic sera of cases (median lead time 14 years) and controls using multiplex serology. Sensitivities were calculated using receiver operating characteristic analysis pre-specified to yield 90% specificity in the control group. From 10 cases, serial samples were available.

RESULTS

Quantitative EBV antibody levels were significantly elevated among all cases (p < 0.05) for three IgA and six IgG antibodies. The highest sensitivities for defining 12 EBER-ISH-positive NPCs were observed for BGLF2 IgA (67%) and BGLF2 IgG (83%). Increased IgA and IgG antibody levels between the first and last draw before diagnosis were observed for EBER-ISH positive, but not for EBER-ISH negative NPCs. Among 21 molecularly analyzed NPCs, 4 EBER-ISH negative NPCs showed concomitant positivity to HPV type-specific DNA and RNA; 3 NPCs were HPV16 and 1 NPC was HPV18 positive.

CONCLUSION

Both, EBV IgA and IgG antibody levels are significantly elevated many years before diagnosis of EBV-positive NPCs in Norway, an NPC low-incidence region. This study provides insights into one of the largest available prospective sample collections of NPCs in a non-endemic country.

A Case Report of Tongue Lymphoepithelial Carcinoma with a Histological Diagnostic Dilemma

Most head and neck lymphoepithelial carcinomas (LECs) arise in the nasopharynx and harbor Epstein–Barr virus (EBV). LEC is also a rare subtype of the oral squamous cell carcinoma (SCC). Morphologically, LEC is defined as resembling non-keratinizing nasopharyngeal carcinoma, undifferentiated subtype. The histological features and pathogenesis of oral LEC are not established. We describe a case of tongue LEC with histopathological diagnostic difficulties. A 72-year-old Japanese female presented with a whitish change on her left-side tongue. The diagnosis was atypical epithelium; neoplastic change could not be ruled out by a biopsy. Although the lesion was monitored at our hospital per her request, invasive carcinoma was detected 11 months later. Microscopically, conventional SCC was observed with the characteristic features as LEC confined to the deep part of the lesion. We briefly discuss this unusual histological finding and make a novel proposal for distinguishing oral LEC from LECs in other regions based on these histological findings.

Tumors of Atypical Carcinoma of the Parotid Gland and Papillary Thyroid Carcinoma: A Case Report

Lymphoepithelial carcinoma (LEC) is a variant of anaplastic carcinoma usually found in the nasopharynx. It is a rare, aggressive malignant tumor in the salivary glands, which is usually associated with Epstein-Barr virus (EBV), and often presents with facial nerve paralysis when in the parotid gland. This case report is unique in that our patient had EBV-negative LEC, with facial nerve involvement and a concurrent primary papillary thyroid carcinoma (PTC). We successfully managed this patient with surgery and adjuvant chemoradiotherapy. The patient has responded well to the treatment and she showed no evidence of disease at the 24-month follow-up.

Epstein-Barr virus and human papillomavirus serum antibodies define the viral status of nasopharyngeal carcinoma in a low endemic country

Epstein-Barr virus (EBV) causes nasopharyngeal carcinoma (NPC) in endemic regions, where almost every tumor is EBV-positive. In Western populations, NPC is rare, and human papillomavirus infection (HPV) has been suggested as another viral cause. We validated multiplex serology with molecular tumor markers, to define EBV-positive, HPV-positive and EBV-/HPV-negative NPCs in the United Kingdom, and analyzed survival differences between those groups. Sera from NPC cases (n = 98) and age- and sex-matched controls (n = 142) from the Head and Neck 5000 clinical cohort study were analyzed. IgA and IgG serum antibodies against 13 EBV antigens were measured and compared with EBER in situ hybridization (EBER-ISH) data of 41 NPC tumors (29 EBER-ISH positive, 12 negative). IgG antibodies to EBV LF2 correctly diagnosed EBV-positive NPCs in 28 of 29 cases, while all EBER-ISH negative NPCs were seronegative to LF2 IgG (specificity = 100%, sensitivity = 97%). HPV early antigen serology was compared to HPV molecular markers (p16 expression, HPV DNA and RNA) available for 41 NPCs (13 positive, 28 negative). Serology matched molecular HPV markers in all but one case (specificity = 100%, sensitivity = 92%). EBV and HPV infections were mutually exclusive. Overall, 67% of the analyzed NPCs were defined as EBV-positive, 18% as HPV-positive and 14% as EBV/HPV-negative. There was no statistical evidence of a difference in survival between the three groups. These data provide evidence that both, EBV-positive and HPV-positive NPCs are present in a low incidence country, and that EBV and HPV serum antibodies correlate with the viral status of the tumor.

Validation of an Epstein-Barr Virus Antibody Risk Stratification Signature for Nasopharyngeal Carcinoma by Use of Multiplex Serology

Serological testing for nasopharyngeal carcinoma (NPC) has recently been reinvigorated by the implementation of novel Epstein-Barr virus (EBV)-specific IgA and IgG antibodies from a proteome array. Although proteome arrays are well suited for comprehensive antigen selection, they are not applicable for large-scale studies. We adapted a 13-marker EBV antigen signature for NPC risk identified by proteome arrays to multiplex serology to establish an assay for large-scale studies. Taiwanese NPC cases (n = 175) and matched controls (n = 175) were used for assay validation. Spearman's correlation was calculated, and the diagnostic value of all multiplex markers was assessed independently using the area under the receiver operating characteristic curve (AUC). Two refined signatures were identified using stepwise logistic regression and internally validated with 10-fold cross validation. Array and multiplex serology showed strong correlation for each individual EBV marker, as well as for a 13-marker combined model on continuous data. Two refined signatures with either four (LF2 and BGLF2 IgG, LF2 and BMRF1 IgA) or two (LF2 and BGLF2 IgG) antibodies on dichotomous data were identified as the most parsimonious set of serological markers able to distinguish NPC cases from controls with AUCs of 0.992 (95% confidence interval [CI], 0.983 to 1.000) and 0.984 (95% CI, 0.971 to 0.997), respectively. Neither differed significantly from the 13-marker model (AUC, 0.992; 95% CI, 0.982 to 1.000). All models were internally validated. Multiplex serology successfully validated the original EBV proteome microarray data. Two refined signatures of four and two antibodies were capable of detecting NPC with 99.2% and 98.4% accuracy.

Molecular Classification of Gastric Cancer among Alaska Native People

Gastric cancer is an aggressive and heterogeneous malignancy that often varies in presentation and disease among racial and ethnic groups. The Alaska Native (AN) people have the highest incidence and mortality rates of gastric cancer in North America. This study examines molecular markers in solid tumor samples from eighty-five AN gastric adenocarcinoma patients using next-generation sequencing, immunohistochemistry, and in situ hybridization analysis. AN patients have a low mutation burden with fewer somatic gene mutations in their tumors compared to other populations, with the most common mutation being TP53. Epstein-Barr virus (EBV) was associated with 20% of AN gastric cancers, which is higher than the world average of 10%. The inflammation marker, cyclooxygenase-2 (COX-2), is highly expressed in patients with the lowest survival rates. Mismatch repair deficiency was present in 10% of AN patients and was associated with patients who were female, 50 years or older, gene mutations, and tumors in the distal stomach. Program death-ligand 1 (PD-L1) was expressed in 14% of AN patients who were more likely to have MMR deficiency, EBV-associated gastric cancers, and mutations in the PIK3CA gene, all of which have been linked to clinical response to PD-1 inhibitors. These studies suggest a portion of AN gastric cancer patients could be candidates for immunotherapy. Overall, this study highlights future avenues of investigation for clinical and translational studies, so that we can improve early detection and develop more effective treatments for AN patients.

Characterization of a new dual-targeting fully human antibody with potent antitumor activity against nasopharyngeal carcinoma

Despite the effectiveness of the anti-EGFR chimeric antibody (mAb), cetuximab, in treating nasopharyngeal carcinoma (NPC), its efficacy remains variable and often modest. In this study, a full human dual targeted anti-EGFR/HER3 antibody, CA1182, was generated from phage display library. CA1182 was as effective as cetuximab or trastuzumab in inhabiting phosphorylation of EGFR or HER2, but it exhibited as much more potent than cetuximab or trastuzumab. Moreover, our studies showed that CA1182 was significantly more effective than cetuximab in prolonging the survival of severe combined immune deficient mice bearing human NPC, suggesting that it might be a promising therapeutic agent for NPC.

Epstein-Barr virus antibodies and the risk of associated malignancies: review of the literature

Epstein-Barr virus (EBV), a ubiquitous herpes virus that infects 90% of humans by adulthood, is linked to the development of various cancers, including nasopharyngeal carcinoma, gastric cancer, Burkitt lymphoma, non-Hodgkin lymphoma (NHL), and Hodgkin lymphoma. We reviewed the literature published since 1980 regarding an association between antibodies against EBV proteins and the risk of EBV-associated malignancies. Immunoglobulin A antibody levels that are elevated before diagnosis have consistently been associated with the risk of nasopharyngeal carcinoma, and patients with Hodgkin lymphoma have significantly higher immunoglobulin G antibody levels than disease-free controls. However, the link between the immune response to EBV and other EBV-associated malignancies was less clear. Although evidence of an association between the risk of Burkitt lymphoma and immunoglobulin G antibodies was consistent for available studies, the sample sizes were limited. Evidence for a link between antibodies against EBV and risk of either gastric cancer or NHL was inconsistent. Future investigations should account for tumor EBV status because only 7%-10% of gastric tumors and select NHL subtypes are related to EBV infection. Comparing differences in the associations between the humoral immune response to EBV and disease risk across cancers may help elucidate how this ubiquitous virus contributes to distinct tumors globally.

Fluctuations of epstein-barr virus serological antibodies and risk for nasopharyngeal carcinoma: a prospective screening study with a 20-year follow-up

Background

The impact of variation of Epstein-Barr virus (EBV) antibody titers before the development of nasopharyngeal carcinoma (NPC) is still unclear. We analyzed the fluctuations of antibodies against EBV before histopathological diagnosis to assess the risk of NPC and aimed to provide a reliable basis for screening in high risk populations.

Methods

This study was based on a population-based screening program in Sihui County in Guangdong Province of China. A total of 18,986 subjects were recruited in 1987 and 1992, respectively. Baseline and repeated serological tests were performed for IgA antibodies against EBV capsid antigen (VCA/IgA) and early antigen (EA/IgA). Follow-up until the end of 2007 was accomplished through linkage with population and health registers. Cox proportional hazards regression model was used to estimate the relative risk of NPC in association with EBV antibodies. Time-dependent receiver operating characteristic curve (ROC) analysis was used to further evaluate the predictive ability.

Results

A total of 125 NPCs occurred during an average of 16.9 years of follow-up. Using baseline information alone or together with repeated measurements, serological levels of VCA/IgA and EA/IgA were significantly associated with increased risks for NPC, with a striking dose-response relationship and most prominent during the first 5 years of follow-up. Considering the fluctuant types of serological titers observed during the first three tests, relative risk was highest among participants with ascending titers of EBV VCA/IgA antibodies with an adjusted hazard ratio (HR) of 21.3 (95% confidence interval [CI] 7.1 to 64.1), and lowest for those with decreasing titers (HR = 1.5, 95% CI 0.2 to 11.4), during the first 5 years of follow-up. Time-dependent ROC analysis showed that VCA/IgA had better predictive performance for NPC incidence than EA/IgA.

Conclusion

Our study documents that elevated EBV antibodies, particularly with ascending titers, are strongly associated with an increased risk for NPC.

Incidence of cancers of the oral cavity and pharynx among American Indians and Alaska Natives, 1999-2004

BACKGROUND

Previous studies identified disparities in incidence rates of cancers of the oral cavity and pharynx between American Indians/Alaska Natives (AI/AN) and non-Hispanic whites (NHW) and differences between various AI/AN populations. Reporting among AI/AN has been hampered by: 1) heterogeneity among various anatomic sites of oral cavity and pharyngeal cancers obscuring unique patterns of individual anatomic sites; 2) race misclassification and underreporting of AI/AN; and 3) sparseness of data needed to identify regional variations.

METHODS

To improve race classification of AI/AN, data from US central cancer registries were linked with Indian Health Service (IHS) records. AI/AN incidence data from 1999 to 2004 were stratified by sex, age, stage at diagnosis, and anatomic subsite for 6 IHS geographic regions and compared with NHW populations.

RESULTS

For all oral cavity and pharynx cancers combined, among residents of Contract Health Service Delivery Area counties, AI/AN overall had significantly lower incidence rates than NHW (8.5 vs 11.0). However, AI/AN rates were significantly higher in the Northern Plains (13.9 vs 10.5) and Alaska (16.3 vs 10.6), significantly lower in the Pacific Coast (7.7 vs 11.6) and Southwest (3.3 vs 10.4), and similar in the Southern Plains (11.4). Overall AI/AN males had higher incidence rates than AI/AN women. Nasopharyngeal cancer was more frequent (1.1AI/AN vs 0.4 NHW), and tongue cancer less frequent (1.6 AI/AN vs 2.9 NHW) in AI/AN than NHW populations; however, rates varied by region. Stage distribution was modestly less favorable for AI/AN compared with NHW populations.

CONCLUSIONS

Variation by region, anatomic site, and sex indicates a need for research into etiologic factors and attention to regional risk factor profiles when planning cancer control programs.

Cancer patterns in Inuit populations

Inuit people inhabit the circumpolar region, with most living in Alaska, northwest Canada, and Greenland. Although malignant diseases were believed to be almost non-existent in Inuit populations during the beginning of the 20th century, the increasing life expectancy within these populations showed a distinct pattern, characterised by a high risk of Epstein-Barr virus-associated carcinomas of the nasopharynx and salivary glands, and a low risk of tumours common in white populations, including cancer of the prostate, testis, and haemopoietic system. Both genetic and environmental factors seem to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet, and reproductive factors. This Review will briefly summarise the current knowledge on cancer epidemiology in Inuit populations, with emphasis on the characteristic Inuit types of cancer.

The enigmatic epidemiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has a unique and complex etiology that is not completely understood. Although NPC is rare in most populations, it is a leading form of cancer in a few well-defined populations, including natives of southern China, Southeast Asia, the Arctic, and the Middle East/North Africa. The distinctive racial/ethnic and geographic distribution of NPC worldwide suggests that both environmental factors and genetic traits contribute to its development. This review aims to summarize the current knowledge regarding the epidemiology of NPC and to propose new avenues of research that could help illuminate the causes and ultimately the prevention of this remarkable disease. Well-established risk factors for NPC include elevated antibody titers against the Epstein-Barr virus, consumption of salt-preserved fish, a family history of NPC, and certain human leukocyte antigen class I genotypes. Consumption of other preserved foods, tobacco smoking, and a history of chronic respiratory tract conditions may be associated with elevated NPC risk, whereas consumption of fresh fruits and vegetables and other human leukocyte antigen genotypes may be associated with decreased risk. Evidence for a causal role of various inhalants, herbal medicines, and occupational exposures is inconsistent. Other than dietary modification, no concrete preventive measures for NPC exist. Given the unresolved gaps in understanding of NPC, there is a clear need for large-scale, population-based molecular epidemiologic studies to elucidate how environmental, viral, and genetic factors interact in both the development and the prevention of this disease.

Expression of Epstein-Barr virus-encoded small nuclear RNA 1 in Japanese nasopharyngeal carcinomas

An examination was made of the incidence of the Epstein-Barr virus (EBV) genome and its exact localization in 39 cases of nasopharyngeal carcinoma (NPC) in Japanese patients by means of in situ hybridization (ISH) with a digoxigenin-labeled Epstein-Barr virus-encoded small nuclear RNA 1 (EBER1) oligonucleotide probe. Hybridization signals were observed in the nucleus of tumor cells in all 39 NPCs, including keratinizing carcinomas. The signals varied greatly in intensity from case to case and even from cell to cell in the same tumor, but were recognized in most tumor cells in each case. Signals could occasionally be seen in limiting number of infiltrating small lymphocytes but were absent in all tumors of the tongue, midpharynx and hypopharynx. Combined immunohistochemistry-ISH studies indicated that EBER1 signals were restricted to tumor cells positive for cytokeratin. As a result of this study, it is now possible to perform large-scale retrospective analyses using routine formalin-fixed, paraffin-embedded tissue sections and to combine ISH for the EBV genome with immunohistochemistry for cytokeratin to determine the epithelial features of EBV genome-possessing cells. All NPCs were clearly shown to be EBV-infected, thus indicating that EBV is essential for the oncogenesis of NPCs.

Epstein-Barr virus and cancers of the head and neck

Denis Burkitt pioneered the association of viruses and cancer in humans with his observations of lymphomatous tumors in children in equatorial Africa. The Epstein-Barr virus (EBV), a human B lymphotrophic herpes virus, is strongly associated with undifferentiated carcinoma of the nasopharynx and African-type Burkitt's lymphoma. More recently, an association of this virus with other epithelial neoplasms, lymphomas, and immunodeficiency-related malignant and nonmalignant conditions has been reported. Since many of these tumors are rare, much of the information is based on sporadic reports and relatively small series of patients. The purpose of this report is to review the literature and examine the growing association of EBV with various head and neck malignancies.

The aetiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma is a disease with a remarkable racial and geographical distribution. In most parts of the world it is a rare condition and in only a handful of places does this low risk profile alter. These include the Southern Chinese, Eskimos and other Arctic natives, inhabitants of South-East Asia and also the populations of North Africa and Kuwait.

Epstein-Barr virus infection in non-carcinomatous gastric epithelium

Gastric tissue specimens from 20 patients with chronic atrophic gastritis, one of whom also had an early gastric carcinoma, were studied for evidence of Epstein-Barr virus (EBV) infection by Southern blot analysis, DNA and RNA in situ hybridization, and immunohistochemistry for the presence of the EBV-determined nuclear antigen 1 (EBNA-1) and the latent membrane protein 1 (LMP-1). EBV DNA was detected in two cases with chronic atrophic gastritis and in the case with early gastric carcinoma by Southern blot hybridization. DNA in situ hybridization showed EBV genomes in the epithelial cells of two other cases with chronic atrophic gastritis and in non-carcinomatous and carcinomatous epithelial cells of the early gastric carcinoma case. EBNA-1 was detected in all cases. LMP-1 was detected in areas of intestinal metaplasia in eight patients with chronic atrophic gastritis. EBV-encoded small RNA 1 (EBER-1) expression was limited to carcinoma cells. These results show that gastric epithelium is frequently infected with EBV and suggest that prolonged EBV persistence may contribute to the development of gastric carcinoma.

Epstein-Barr virus in tumours

The Epstein-Barr virus (EBV) is the best characterized human virus known to infect most people all over the world. In most cases, primary infection with EBV is asymptomatic and the virus persists life-long without causing any disease. The availability of sensitive detection methods, however has led to the identification of a wide array of EBV-associated disease entities. Although nearly 9000 publications have been written since the first description of this virus in 1964, many questions concerning its function and infection patterns remain unanswered. The direct involvement of EBV in the pathogenesis of a disease has only been established for infectious mononucleosis and lymphoproliferative disorders in the setting of congenital or acquired immunodeficiency. Extensive investigations on the role of EBV infection in the pathogenesis of all other EBV-associated lymphoid and epithelial proliferations have led to the conclusion that EBV is not the primary causative agent but it can promote tumour development. Since the early steps in neoplastic development are difficult to assess, further studies are required to clarify the precise role of EBV infection. Furthermore, the clinical significance of the presence of EBV in neoplasia is largely unknown.

Expression of Epstein-Barr virus in carcinomas of major salivary glands: a strong association with lymphoepithelioma-like carcinoma

To elucidate the role of Epstein-Barr virus (EBV) in salivary gland carcinomas, 56 cases of carcinomas of major salivary glands were investigated. These included 14 mucoepidermoid carcinomas, 13 adenoid cystic carcinomas, seven malignant mixed tumors, four adenocarcinomas, four salivary duct carcinomas, two acinic cell carcinomas, two undifferentiated carcinomas without lymphoid stroma, seven lymphoepithelioma-like carcinomas (LELCs), two squamous cell carcinomas, and one small cell carcinoma. EBV transcripts were examined by in situ hybridization using digoxigenin-labeled oligonucleotide antisense probe for EBV-encoded RNA 1 (EBER1) on formalin-fixed paraffin-embedded tissue sections. EBER1 was detected in the malignant epithelial cells in all seven cases of LELC, but not in any of the other carcinomas and the neighboring normal salivary gland tissue. Because all the EBV-negative cases showed satisfactory labeling with the poly d(T) probe, the negative reaction with EBER1 was unlikely to be caused by poor RNA preservation in the tissues. The seven cases of LELC, which were histologically indistinguishable from undifferentiated nasopharyngeal carcinoma (NPC), had a disease-free 4-year survival rate of 85.7%. The results suggest that LELC of the salivary gland in Taiwanese Chinese may share similar EBV-related pathogenesis with that of NPC.

Expression of EBER1 in primary and metastatic nasopharyngeal carcinoma tissues using in situ hybridization. A correlation with WHO histologic subtypes

BACKGROUND

The association of Epstein-Barr virus (EBV) with nasopharyngeal carcinoma (NPC) is well documented. Previous studies reported abundant expression of EBER1 in primary NPC and tumors metastatic to lymph nodes. However, a large series of case studies correlating World Health Organization (WHO) histologic subtypes with EBER1 is needed.

METHODS

The authors applied the EBER1 in situ hybridization to investigate the expression of EBER1 in 140 primary NPCs, 11 metastatic tumors to lymph nodes, 6 metastatic tumors to bone marrow, and 2 metastatic tumors to the liver. All 19 metastatic tumors had paired specimens from their primary NPCs for comparison. The in situ hybridization method was performed on paraffin embedded tissues by using polymerase chain reaction-derived, digoxigenin-labelled EBER1 DNA probes.

RESULTS

The EBER1 signal was identified in nuclei of malignant epithelial cells in 135 of 140 (96.4%) primary NPCs, including 4 of 5 (80%) WHO-I histologic subtypes, 71 of 73 (97.3%) WHO-II histologic subtypes, and 60 of 62 (96.8%) WHO-III histologic subtypes (P > 0.05). However, the positive hybridization signal in WHO-I NPC was less in proportion to malignant cells, usually limited to basal cells, than in other histologic types of NPC. In 10 of 11 specimens with metastases to the lymph nodes, hybridization was always limited to the malignant cells and not associated with lymphocytes. All 10 paired primary NPCs also demonstrated positive EBER1 hybridization. Only one paired specimen showed negative EBER1 in primary NPC and a metastases to a lymph node. Eight distant metastases, all EBER1-positive in their primary NPC, also demonstrated positive EBER1 hybridization signals in the malignant cells. The proportion of EBER1 positivity in metastatic NPC is higher than that in primary lesions as observed in paired specimens from the same patient.

CONCLUSIONS

Because of abundant expression of EBER1 in primary NPC as well as in metastatic malignant cells, it is recommended that EBER1 in situ hybridization be performed on routinely processed specimens whenever NPC is suspected.

Cancers of the buccal cavity and pharynx in Circumpolar Inuit

In an international collaboration, cancers of the buccal cavity and pharynx were combined from cancer registries in the Circumpolar region, including Alaska, Canada and Greenland. Low risk of cancers of the lip (SIR 0.2) was observed among Inuit. Increased risk of cancer of the tongue and oral cancer (SIR 2.5) were observed among Greenlandic Inuit men. Salivary gland cancer and nasopharyngeal cancer occur among Inuit with rates among the highest in the world. Environmental factors (EBV, diet) and a genetically susceptible population are believed to play a role.

Detection of EBV DNA in post-nasal space biopsy tissue from asymptomatic EBV-seropositive individuals

The association between EBV and nasopharyngeal carcinoma (NPC) has been well documented although the precise role of the virus in the genesis of the tumour is not understood. We undertook this study to examine the prevalence of EBV infection in nasopharyngeal tissue obtained from 33 healthy individuals not considered to be at risk of developing NPC. Using polymerase chain amplification (PCR) and in situ hybridization we have identified EBV DNA in 70% (23/33) of the tissues examined. Our data demonstrate that EBV is present at the site of tumour development in the low-risk population and by inference that the virus is also present before the onset of disease in the high-risk group. This survey supports the concept of NPC pathogenesis as a multifactorial process.

A simple and rapid technique to process formalin-fixed, paraffin-embedded tissues for the detection of viruses by the polymerase chain reaction

The use of chelating resin in a simple, rapid and efficient pre-treatment protocol to process formalin-fixed, paraffin-embedded specimens for the polymerase chain reaction (PCR) is described and compared to other pre-treatment techniques. With this modified PCR protocol, a variety of human autopsy and biopsy specimens were investigated for presence of DNA of human papilomaviruses, cytomegalovirus or Epstein-Barr virus. These viruses were detected in a productive or non-/low-productive state. Amplimers generated ranged from 88 to 450 base pairs length. Under the specified technical conditions, a considerable range of DNA molecules can be amplified from paraffin-embedded material, some older than 10 years.

Undifferentiated carcinoma of the salivary gland in Greenlandic Eskimos: demonstration of Epstein-Barr virus DNA by in situ nucleic acid hybridization

Paraffin sections of 11 undifferentiated salivary gland carcinomas of lymphoepithelioma type (malignant lymphoepithelial lesion) arising in Greenlandic Eskimos (Inuit) were examined for the presence of Epstein-Barr virus (EBV) using in situ nucleic acid hybridization with a 35S-labeled EBV-specific probe. Epstein-Barr virus genomes were detected in each case in malignant epithelial cells, but were not found in lymphoid stroma or in residual benign salivary epithelium. Eight undifferentiated salivary gland carcinomas from non-Eskimo patients (including two with lymphoepithelioma-like features) were negative for EBV-DNA. Our results confirm the existence of a consistent and specific association between EBV and tumor cells of undifferentiated salivary gland carcinoma of lymphoepithelioma type arising in Greenlandic Eskimos.

Diet and nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a disease with a remarkable racial and geographical distribution. It is very rare (incidence of less than 1 per 100,000 person-years) in most parts of the world and only a handful of populations are known to deviate from this low-risk profile, which include people of southern China. Eskimos and other natives of the Arctic region, natives of southeast Asia, and mainly Arab populations of north Africa and Kuwait. There is now convincing evidence implicating dietary factors as the primary cause of NPC among Chinese. A series of case-control studies conducted in various Chinese populations with distinct risks of NPC, ranging from the very high-risk Cantonese to the relatively low-risk Northern Chinese, have suggested that ingestion of salted fish and other kinds of preserved foods by the Chinese constitutes the most important cause of NPC development among these people. Preliminary data on Malays in southeast Asia, Eskimos in Alaska, and Arabs of north Africa also suggest that ingestion of preserved foods by these population groups may be responsible for their raised incidence of NPC.

Epstein-Barr virus infection in cultured non-malignant epithelial cells from human nasopharyngeal mucosa

Epstein-Barr virus infected cultured epithelial cells from the human nasopharyngeal mucosa only, when the cells were maintained under conditions preventing terminal differentiation. The infection of these cells resulted in a marked cytopathology resembling that morphology induced in cell cultures by other members of the herpesvirus group.

Viruses and salivary gland disease: are there associations?

Viruses can cause sialadenitis and may be associated with other diseases of salivary glands, particularly immunologically mediated and neoplastic lesions. The evidence that such an association with Sjögren's syndrome is causal is reviewed here and shown to be fairly tenuous at present.

Cancer pattern among Greenlandic Inuit migrants in Denmark, 1968-1982

For several cancer sites the incidence among Inuit (Eskimos) in Alaska, Canada and Greenland differs markedly from that in non-Inuit in adjacent areas. This is the first study of Inuit migrants. Among 11,571 Inuit Greenlandic people living in Denmark in the period 1968-1982 we found 69 cases of cancer. Significantly increased risks compared to the Danish population were found for cancer of the rectum (RR = 5.5) in males and for nasopharyngeal cancer (RR = 185.2) and cancer of the cervix uteri (RR = 1.9). The significance of these findings in relation to the role of environmental factors in the aetiology of cancer in Inuit is discussed.

Nasopharyngeal carcinoma in Israel: epidemiology and Epstein-Barr virus-related serology

Epidemiological, histological and serological characteristics of nasopharyngeal carcinoma (NPC) were investigated. Included were 25 patients aged 10-70 with male to female ratio 2:1. Among 23 Jewish patients, 18 were of Asian-African (AA) and five of European (Eur) descent; two were Arabs (Ar). The dominant histological type among AA patients was undifferentiated carcinoma (UCNT) and among Eur squamous cell carcinoma (SCC). Elevated IgG and IgA antibodies to Epstein-Barr (EBV) viral capsid, early and nuclear antigens were observed in patients, as compared to 34 healthy controls matched by age, sex and ethnic origin. Although not statistically significant, antibodies to EBV were elevated in AA, as compared to Eur patients. No significant differences in IgG and IgA antibodies to Herpes simplex, Cytomegalo and Varicella-zoster viruses were demonstrated among patients and controls. The study suggests that NPC in Israel, as elsewhere, is associated with EBV and genetic or environmental factors may influence the prevalence of NPC among certain ethnic groups.

Epstein-Barr virus and jaw tumors in North Nigeria

Nigerian patients with tumors of the jaw were compared with controls in respect of antibodies to the viral capsid antigens of Epstein-Barr Virus (EBV) and of total immunoglobulin levels. Immunoglobulin levels did not differ between patients and controls but increased two weeks postsurgery. Immunoglobulin A (IgA) antibodies to EBV were detected in a small number of patients, and mean titers of IgG antibodies to EBV were lower in the patient group, indicating a lack of association between EBV and tumor formation. An association was noted between the presence of Hepatitis B surface antigen, and depressed antibody titers to EBV in patients with tumors. Of 78 patients studied, 12% were Hepatitis B surface antigen positive.

The differentiated form of nasopharyngeal carcinoma contains Epstein-Barr virus DNA

Immunologic studies of Epstein-Barr virus (EBV) have implicated EBV in undifferentiated and partially differentiated, non-keratinizing nasopharyngeal carcinoma (NPC). Patients with the well-differentiated, keratinizing form of NPC have EBV serologic patterns similar to those of control populations. In addition, viral DNA has not been detected in the differentiated tumors using viral cRNA probes to DNA immobilized on filters. In this study we have tested for EBV DNA using recombinant DNA probes to Southern blots of DNA from 33 NPC specimens. The 24 undifferentiated and 4 partially differentiated specimens generally contained a relatively high number of EBV genome equivalents, while the 5 well-differentiated NPC all contained detectable EBV, but at low copy number. The viral DNA from one of the well-differentiated specimens was cloned into a cosmid vector. Five recombinant clones representing the fused viral termini were obtained, indicating the presence of episomal, intracellular DNA in the tumor. These findings indicate that all histologic subsets of NPC contain EBV DNA.

Epstein-Barr virus-associated malignancies

The infectious aspects of cancer in humans were epidemiologically pioneered by Dr. David Burkitt through his observations of lymphomatous tumors seen in children in equatorial Africa. Years, later, the Epstein-Barr virus (EBV) was shown to be intimately associated with such tumors and is now recognized as a component of some B-cell lymphomas and nasopharyngeal carcinoma. Still the questions of an active, passive, or accessory role persist. The ability of this virus to cause immunosuppressive hemopoietic disturbances in individuals infected with EBV but not developing cancer raise questions about host susceptibility, host immune response, and possible coconspiring, infectious, oncogenic agents. Recent associations of EBV antibody found in diseases, such as squamous cell carcinoma of the head and neck and acquired immunodeficiency syndromes, point to its possible accessory role as an immunosuppressive agent. The ability of EBV to spread by extracellular and intracellular mechanisms demonstrates its variable infectious potential. Numerous EBV-transformed human cell lines attest to its ability to confer "immortality" with uncontrolled growth patterns. This review critically examines the association of EBV with various malignancies, the type of evidence which links it there, and the implications for further investigations and therapy.

Familial clustering of salivary gland carcinoma in Greenland

Salivary gland carcinoma (SGC) occurs at an increased frequency in the Eskimo population. In Greenland the incidence of SGC is 4.5-fold higher for men and 9-fold higher for women as compared with European incidence. The increased incidence is caused by low-differentiated carcinoma. Unusual familial clustering of SGC is reported among two families (five siblings). Peculiar aspects of racial and geographical distribution and possible role of genetic and environmental factors in the etiology of this relatively uncommon tumor are briefly discussed with special emphasis on the recently detected association between the Eskimos' SGC and the Epstein-Barr virus.

Prognostic determinants and a new view of staging for patients with nasopharyngeal carcinoma

There is no agreement on the single best staging system for patients with nasopharyngeal carcinoma. We have evaluated prospectively several staging systems and have assessed the predictive value of many variables on survival and found that the most important are extensive tumor within the nasopharynx or regional extension, nodes in the lower portion of the neck, and cranial nerve involvement. Other variables that have not been used in traditional extent of disease staging systems but that have an adverse bearing on survival have been studied by multiple regression techniques in the Cox proportional hazards model. Two prognostic scores, which can be used for classifying patients into survival groups, ranging from excellent survival (low score) to poor survival (high score), have also been presented. With these schemes, patients who are at high risk for recurrence after conventional therapy can be reliably selected.

Epstein-Barr virus-specific serodiagnostic tests in carcinomas of the head and neck

Sera from 256 patients with cancers of the head and neck were examined for their profiles of IgG and IgA antibodies to Epstein-Barr virus (EBV)-specific, viral capsid antigen (VCA), the diffuse (D) and the restricted (R) components of the early antigen (EA) complex, and the EBV-associated nuclear antigen (EBNA), in order to assess the value of these procedures in the routine diagnosis of poorly or undifferentiated nasopharyngeal carcinoma (NPC). In 13 NPC patients, the carcinoma had invaded cervical lymph nodes, and their sera revealed, in addition to high IgG anti-VCA titers, elevated levels of IgA antibodies to VCA, of IgG antibodies to D, and most also had IgA anti-D. Such profiles were seen in very few of the patients with carcinomas at other sites of the head and neck. They had not developed in four NPC patients whose tumors were limited to the postnasal space, and in three patients with other tumors at that site. Among 15 patients with cervical node metastases from occult primary tumors, 2 had EBV-specific antibody profiles compatible with NPC, 1 was judged to have NPC on clinical grounds, and the other died of a pulmonary carcinoma, or possibly pulmonary metastases. In 4 of the remaining 13 patients with occult tumors, the primary site was found outside the nasopharynx, whereas it escaped detection in the other 9. These results lend further support to the usefulness of the EBV-specific serology to clinicians in the diagnosis of NPC, especially in cases of lymph node invasion by undetected primary tumors. The data also emphasize the need of complementing the serology with the examination of biopsies for the presence of EBV deoxyribonucleic acid (DNA) or, more readily performed, EBNA-positive carcinoma cells.

Antibody responses to Epstein-Barr virus-specific DNase in relation to the prognosis of juvenile patients with nasopharyngeal carcinoma

We have examined serial sera from 17 juvenile patients with nasopharyngeal carcinoma (NPC) for their capacity to neutralize the activity of Epstein-Barr virus (EBV)-specific DNase. The results revealed that NPC patients who became long-term survivors (LTS) without evidence of the disease either never possessed significant levels of antibodies to the enzyme or showed a gradual decline in the number of EBV DNase units neutralized from an elevated level at diagnosis to an insignificant figure several years later. All the 10 LTS neutralized less than 4, and some neutralized less than 2 units of the enzyme 3 or more years after the initial diagnosis. In contrast, serial sera from juvenile patients who died of NPC neutralized over 10 and as many as 25 units of EBV DNase either persistently until death occurred or with transient declines during unmaintained remissions. Rises and declines in the neutralizing activity were, with few exceptions, accompanied by corresponding changes in the titers of IgA and IgG antibodies to EB viral capsid antigen and to the diffuse component of the early antigens. Although the number of juvenile NPC cases available for study was small, the observations suggest that the EBV DNase neutralization test may serve to provide information on the prognosis of the patients.

Epstein-Barr virus in nasopharyngeal and salivary gland carcinomas of Greenland Eskimoes

Biopsy specimens from nasopharyngeal carcinomas (NPC) or salivary-gland carcinomas (SGC) in Greenland Eskimoes were examined for the presence of Epstein-Barr virus (EBV) DNA and sera from the patients were tested for EBV-specific antibody titres. Six out of 7 NPCs and one from an undifferentiated SGG were positive for EBV DNA. The EBV-specific antibody spectra and titres of the patients with NPC or undifferentiated SGG conformed to the results of earlier studies in other high-incidence areas.