Viral load of HPV in esophageal squamous cell carcinoma

Overview of Risk Factors for Esophageal Squamous Cell Carcinoma in China

(1) Background: China has the highest esophageal squamous cell carcinoma (ESCC) incidence areas in the world, with some areas of incidence over 100 per 100,000. Despite extensive public health efforts, its etiology is still poorly understood. This study aims to review and summarize past research into potential etiologic factors for ESCC in China. (2) Methods: Relevant observational and intervention studies were systematically extracted from four databases using key terms, reviewed using Rayyan software, and summarized into Excel tables. (3) Results: Among the 207 studies included in this review, 129 studies were focused on genetic etiologic factors, followed by 22 studies focused on dietary-related factors, 19 studies focused on HPV-related factors, and 37 studies focused on other factors. (4) Conclusions: ESCC in China involves a variety of factors including genetic variations, gene-environment interactions, dietary factors like alcohol, tobacco use, pickled vegetables, and salted meat, dietary behavior such as hot food/drink consumption, infections like HPV, poor oral health, gastric atrophy, and socioeconomic factors. Public health measures should prioritize genetic screening for relevant polymorphisms, conduct comprehensive investigations into environmental, dietary, and HPV influences, enhance oral health education, and consider socioeconomic factors overall as integral strategies to reduce ESCC in high-risk areas of China.

Causal Link of Human Papillomavirus in Barrett Esophagus and Adenocarcinoma: Are We There Yet?

Esophageal cancer is a relatively common malignancy worldwide with a high mortality (5-year survival of <15%). Despite screening, surveillance, improved imaging and treatment, the exponential rise in OAC continues. The strongest risk factors for OAC are chronic heartburn and metaplastic transformation of the lower third of the esophagus (Barrett's esophagus). The risk profile includes Caucasian race, male gender older age, obesity and smoking. Although the tumor risk in BO has been progressively revised downwards, the exponential rise in OAC remains unchecked. This paradox points to an unidentified missing link. Relatively recently, we provided the world's initial data for a strong association of biologically relevant hr-HPV with BD and OAC. Since then, systematic reviews and meta-analysis have documented HPV DNA prevalence rates in OAC of between 13 to 35%. In this review, we provide some evidence for a probable causal relationship between hr-HPV and OAC. This is challenging given the multifactorial etiology and long latency. Increasingly, high-risk HPV (hr-HPV) is regarded as a risk factor for OAC. This discovery will aid identification of a sub-group of high-risk progressors to esophageal cancer by surveillance and the development of effective preventive strategies including vaccination.

Clonal relationship and alcohol consumption-associated mutational signature in synchronous hypopharyngeal tumours and oesophageal squamous cell carcinoma

BACKGROUND

The patients with dual oesophageal squamous cell carcinoma (ESCC) and hypopharyngeal cancer (HPC) have poor prognosis; their underlying genetic pathogenesis is unclear. We hypothesise that development of synchronous ESCC/HPC depends on multicentricity or independent origin, rather than multifocality due to local or lateral spreading.

METHOD

Multiple region whole-exome sequencing (M-WES) and clonality analysis were used to assess clonal relationship and spatial inter- or intra-tumour heterogeneity (ITH) in 62 tumour regions from eight dual ESCC/HPC and ten ESCC patients.

RESULTS

All synchronous ESCC/HPC patients had COSMIC 16 mutation signatures, compared to only 40% ESCC in the current study (p = 0.013) and public data set (n = 165, p = 0.003). This alcohol consumption-related mutation signature 16, commonly involved in multiple alcohol-related cancers, was significantly associated with drinking and alcohol metabolism-related ADH1B rs1229984. The mutational landscape and copy number profiles were completely distinct between the two primary tumours; clonality analysis further suggested the two primary tumours shared no or only one clone accompanying independent subclone evolution. M-WES strategy demonstrated higher sensitivity and accuracy for detection of mutational prevalence and the late branch mutations among different regions in the ESCC tumours, compared to traditional sequencing analysis based on single biopsy strategy. Patients with high ITH assessed by cancer cell fraction analysis after M-WES were significantly associated with both relapse and survival.

CONCLUSIONS

Our hypothesis-generating M-WES ITH assessment data have implications for prognostication. Collectively, our findings support multicentric independent clonal evolution, the field cancerisation theory, and suggest novel insights implicating an aetiologic role of alcohol metabolism in dual ESCC/HPC carcinogenesis.

Detection of HPV infection in urothelial carcinoma using RNAscope: Clinicopathological characterization

Background

Human papillomavirus (HPV) is a well‐established mucosotropic carcinogen, but its impact on urothelial neoplasm is unclear. We aimed to clarify the clinical and pathological features of HPV‐related urothelial carcinoma (UC).

Methods

Tissue samples of 228 cases of UC were obtained from the bladder, upper and lower urinary tract, and metastatic sites to construct a tissue microarray. The samples were analyzed for the presence of HPV by a highly sensitive and specific mRNA in situ hybridization (RISH) technique (RNAscope) with a probe that can detect 18 varieties of high‐risk HPV. We also conducted immunohistochemistry (IHC) for a major HPV capsid antibody and DNA‐PCR.

Results

The HPV detection rates varied among the methods; probably due to low HPV copy numbers in UC tissues and the insufficient specificity and sensitivity of the IHC and PCR assays. The RISH method had the highest accuracy and identified HPV infection in 12 (5.2%) of the cases. The histopathological analysis of the HPV‐positive UC showed six cases of usual type UC, five cases of UC with squamous differentiation (UC_SqD), and one case of micropapillary UC. The HPV detection rate was six‐fold higher in the cases of UC_SqD than in the other variants of UC (odds ratio [OR] =8.9, p = 0.002). In addition, HPV infection showed a significant association with tumor grade (OR =9.8, p = 0.03) and stage (OR =4.7, p = 0.03) of UC. Moreover, the metastatic rate was higher in HPV‐positive than in negative UC (OR =3.4).

Conclusion

These data indicate that although the incidence of HPV infection in UC is low, it is significantly associated with squamous differentiation and poor prognosis. Furthermore, our observations show that RNAscope is an ideal method for HPV detection in UC compared with the other standard approaches such as IHC and PCR assays.

Prevalence of the integration status for human papillomavirus 16 in esophageal carcinoma samples

BACKGROUND/AIMS

To investigate the etiology of esophageal cancer (EC) related with human papillomavirus (HPV) infection.

MATERIALS AND METHODS

Fresh surgically resected tissue samples and clinical information were obtained from 189 patients. Genomic DNA was extracted, and HPV was detected using polymerase chain reaction (PCR) with HPV L1 gene primers of MY09/11; HPV16 was detected using HPV16 E6 type-specific primer sets. Copies of HPV16 E2, E6, and the human housekeeping gene β-actin were tested using quantitative PCR to analyze the relationship between HPV16 integration and esophageal squamous cell carcinoma and the relationship between the HPV16 integration status and clinical information of patients.

RESULTS

Of the 189 samples, 168 HPV-positive samples were detected, of which 76 were HPV16 positive. Among the HPV16 positive samples, 2 cases (E2/E6 ratio>1) were 2.6% (2/76) purely episomal, 65 (E2/E6 ratio between 0 and 1) were 85.6% (65/76) mixture of integrated and episomal, and 9 (E2/E6 ratio=0) were 11.8% (9/76) purely integrated. The results indicate that integration of HPV16 was more common in the host genome than in the episome genome. The prevalence rate of HPV16 integration is increasing with the pathological stage progression of esophageal carcinoma (EC).

CONCLUSION

A high prevalence of HPV16 suggested that HPV16 has an etiological effect on the progress of EC. Integration of HPV16 is more common than episome genome in the host cells, indicating that continuous HPV infection is the key to esophageal epithelial cell malignant conversion and canceration.

Detection of HPV16 in Esophageal Cancer in a High-Incidence Region of Malawi

This study was designed to explore the role of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC). Fifty-five patients receiving diagnostic upper gastrointestinal endoscopy at Zomba Central Hospital or Queen Elizabeth Hospital in Blantyre (Malawi) in 2010, were included in our study. Formalin-fixed paraffin-embedded biopsies were collected for histopathological diagnosis. HPV DNA was detected using multiplex Quantitative PCR (qPCR) and in situ hybridization (ISH). p16INK4a staining served as a surrogate marker for HPV oncogene activity. Cell proliferation was determined by Ki-67 staining. Human immunodeficiency virus (HIV) status was evaluated by serology. Data on the consumption of alcohol and tobacco, and history of tuberculosis (TBC), oral thrush, and Herpes zoster, were obtained by questionnaire. Forty patients displayed ESCC, three displayed dysplastic epithelium, and 12 displayed normal epithelium. HPV16 was detected in six ESCC specimens and in one dysplastic lesion. Among HPV-positive patients, viral load varied from 0.001 to 2.5 copies per tumor cell. HPV DNA presence could not be confirmed by ISH. p16INK4a positivity correlated with the presence of HPV DNA (p = 0.03). Of particular note is that the Ki-67 proliferation index, in areas with diffuse nuclear or cytoplasmatic p16INK4a staining ≥50%, was significantly higher in HPV-positive tumors compared to the corresponding p16INK4a stained areas of HPV-negative tumors (p = 0.004). HPV infection in ESCC was not associated with the consumption of tobacco or alcohol, but there were significantly more patients drinking locally brewed alcohol among HPV-positive tumor patients compared to non-tumor patients (p = 0.02) and compared to HPV-negative tumor patients (p = 0.047). There was no association between HIV infection, history of TBC, Herpes zoster, oral thrush, or HPV infection, in ESCC patients. Our indirect evidence for viral oncogene activity is restricted to single tumor cell areas, indicative of the role of HPV16 in the development of ESCC. The inhomogeneous presence of the virus within the tumor is reminiscent of the "hit and run" mechanism discussed for β-HPV types, such as HPV38.

HPV, KRAS mutations, alcohol consumption and tobacco smoking effects on esophageal squamous-cell carcinoma carcinogenesis

Esophageal squamous-cell carcinoma (ESCC) is an invasive neoplastic disease generally associated with poor survival rates. The incidence of ESCC is characterized by marked geographic variation, with highest rates noted in developing Southeastern African, Central and Eastern Asian countries. In the developed Western European and North American regions where there is a low disease incidence, heavy alcohol and cigarette consumption constitute major risk factors. The toxic effects of both these risk factors cause chronic irritation and inflammation of the esophageal mucosa, while at the cellular level they further confer mutagenic effects by the activation of oncogenes (e.g., RAS mutations), inhibition of tumor-suppressor genes, and profound DNA damage. Viral infections, particularly with human papillomavirus, may activate specific antiapoptotic, proliferative and malignant cellular responses that may be intensified in combination with the effects of alcohol and tobacco. In countries with a high ESCC incidence, low socioeconomic status and an inadequate diet of poorly preserved food are combined with basic nutritional deficiencies and inadequate medical treatment. These conditions are favorable to the above-mentioned risk factors implicated in ESCC development, which may be present and/or habitually used in certain populations. New perspectives in epidemiological studies of ESCC development and its risk factors allow genome-wide research involving specific environments and habits. Such research should consist of adequately large and representative samples, should use newly designed informative genetic markers, and apply genomic variation analysis of the functional transcripts involved in malignant cell cycle regulation and neoplastic transformation in the multi-step process of ESCC carcinogenesis.

Evaluation of the Prevalence of Human Papillomavirus and Epstein-Barr Virus in Esophageal Squamous Cell Carcinomas

The aim of this study was to determine the possible involvement of human papillomavirus and Epstein-Barr virus in esophageal squamous cell cancer (ESCC) carcinogenesis in the Greek population. DNA was extracted from 30 ESCC and 27 normal esophageal specimens and screened for HPV type-specific or EBV infection by PCR-based assay. Seventeen out of 30 ESCC specimens (56%) were found positive for HPV DNA, of which 15 (88%) were typed as HPV-18 infected, one (5.9%) as HPV-16 infected, and one (5.9%) as infected by an HPV type different from the studied HPV-6, 11, 16, 18 and 33 subtypes. Six of the 27 normal esophageal specimens (22.2%) were positive for HPV infection, five typed as HPV-18 (83.3%) and one as HPV-16 (16.7%). All samples were negative for EBV genome detection as assessed by the PCR assay. No statistically significant correlation was found between the HPV status of the tumor samples and clinical parameters including sex, age of the patients, tobacco or alcohol use, differentiation grade of the lesions and stage of the disease. In conclusion, our findings indicate a statistically significant (p<0.001) overall association between ESCC and HPV infection, mostly related to the HPV-18 subtype, in the Greek population.

Mucosal alpha-papillomaviruses are not associated with esophageal squamous cell carcinomas: Lack of mechanistic evidence from South Africa, China and Iran and from a world-wide meta-analysis

Epidemiological and mechanistic evidence on the causative role of human papillomaviruses (HPV) in esophageal squamous cell carcinoma (ESCC) is unclear. We retrieved alcohol- and formalin-fixed paraffin-embedded ESCC tissues from 133 patients seropositive for antibodies against HPV early proteins, from high-incidence ESCC regions: South Africa, China and Iran. With rigorous care to prevent nucleic acid contamination, we analyzed these tissues for the presence of 51 mucosotropic human alpha-papillomaviruses by two sensitive, broad-spectrum genotyping methods, and for the markers of HPV-transformed phenotype: (i) HPV16/18 viral loads by quantitative real-time PCR, (ii) type-specific viral mRNA by E6*I/E6 full-length RT-PCR assays and (iii) expression of cellular protein p16(INK4a). Of 118 analyzable ESCC tissues, 10 (8%) were positive for DNA of HPV types: 16 (4 tumors); 33, 35, 45 (1 tumor each); 11 (2 tumors) and 16, 70 double infection (1 tumor). Inconsistent HPV DNA+ findings by two genotyping methods and negativity in qPCR indicated very low viral loads. A single HPV16 DNA+ tumor additionally harbored HPV16 E6*I mRNA but was p16(INK4a) negative (HPV16 E1 seropositive patient). Another HPV16 DNA+ tumor from an HPV16 E6 seropositive patient showed p16(INK4a) upregulation but no HPV16 mRNA. In the tumor tissues of these serologically preselected ESCC patients, we did not find consistent presence of HPV DNA, HPV mRNA or p16(INK4a) upregulation. These results were supported by a meta-analysis of 14 other similar studies regarding HPV-transformation of ESCC. Our study does not support the etiological role of the 51 analyzed mucosotropic HPV types in the ESCC carcinogenesis.

Liquid Biopsy of Hepatocellular Carcinoma: Circulating Tumor-Derived Biomarkers

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide due to latent liver disease, late diagnosis, and nonresponse to systemic treatments. Till now, surgical and/or biopsy specimens are still generally used as a gold standard by the clinicians for clinical decision-making. However, apart from their invasive characteristics, tumor biopsy only mirrors a single spot of the tumor, failing to reflect current cancer dynamics and progression. Therefore, it is imperative to develop new diagnostic strategies with significant effectiveness and reliability to monitor high-risk populations and detect HCC at an early stage. In the past decade, the potent utilities of “liquid biopsy” have attracted intense concern and were developed to evaluate cancer progression in several clinical trials. “Liquid biopsies” represent a series of noninvasive tests that detect cancer byproducts easily accessible in peripheral blood, mainly including circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) that are shed into the blood from the tumor sites. In this review, we focus on the recent developments in the field of “liquid biopsy” as well as the diagnostic and prognostic significance of CTCs and cfNAs in HCC patients.

Barrett's oesophagus: can meaningful screening and surveillance guidelines be formulated based on new data and rejigging the old paradigm?

Gastro-oesophageal reflux disease (GORD) and Barrett's oesophagus (BO) have been considered to be the most important known risk factors for oesophageal adenocarcinoma (OAC). It has been the fastest growing cancer in the Western World and has occurred against a backdrop of progressive reduction in the risk estimate of malignancy associated with BO and no reduction in mortality from OAC using the prevailing screening and surveillance guidelines. The recently published link between high risk HPV and Barrett's dysplasia/cancer may be the 'missing' strong risk factor responsible for the significant rise of OAC since the 1970's, as has been the case with head and neck tumours, another viral associated cancer. P53 immunohistochemistry has been proposed as a good molecular marker for predicting disease progression in BD. Nevertheless, significant negative staining for this mutation in BD remains a major hurdle to widespread routine clinical use as a sole molecular marker. Recent data raises the distinct possibility of at least 2 (probably more) carcinogenic pathways operating in OAC. One is HPV mediated devoid largely of p53 mutations and the other p53 dependent. The joint use of both these markers as part of a molecular panel may represent the best bet yet of detecting the high risk group of progressors to OAC. Patients who are positive for either or both biomarkers i.e p53 or/and transcriptional markers of HPV may warrant more intensive screening. In future, genome wide technology may provide molecular signatures to aid diagnosis and risk stratification in BO.

Infection and esophageal cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.

Human papillomavirus 16/18 E7 viral loads predict distant metastasis in oral cavity squamous cell carcinoma

BACKGROUND

Human papillomaviruses (HPV) seem to be related to distant metastasis (DM) in advanced oral cavity squamous cell carcinoma (OSCC) patients.

OBJECTIVES

This study aimed to investigate whether high-risk HPV viral load may predict DM among OSCC patients and stratify patients for risk-adapted treatment.

STUDY DESIGN

Viral loads of E7 oncogenes for HPV 16/18 were measured by quantitative PCR tests in paraffin-embedded lesional specimens from 312 OSCC of which the HPV genotypes had been determined previously. Multivariable Cox regression analysis was used to identify the independent prognostic factors for 5-year DM and C statistics were further computed.

RESULTS

By multivariable analysis, high HPV 16 E7 viral load (≥15.0 copies/genome); high HPV 18 E7 viral load (≥15.0 copies/genome); pathological N2 status (pN2); tumor depth ≥11 mm; extracapsular spread (ECS); and level IV/V metastases were independent risk factors for DM. We further identified three prognostic groups. In the high-risk group (level IV/V metastases or high HPV 16/18 E7 viral load plus pN2, tumor depth ≥11 mm, or ECS), the 5-year distant metastasis rate was 74%. In the intermediate-risk group (high HPV 16/18 E7 viral load, pN2, tumor depth ≥11 mm, or ECS), the 5-year DM rate was 17%. Finally, the 5-year DM rate was 1% in the low-risk group (no risk factors). The value of the C statistics was 0.78.

CONCLUSIONS

Among OSCC patients, high HPV 16/18 E7 viral load identifies a small subgroup of patients at high-risk of 5-year DM and suggest the need for more intensive treatments and follow-up strategies.

Association between human papillomavirus (HPV) and oesophageal squamous cell carcinoma: a meta-analysis

SUMMARY

The oncogenic potential of human papillomaviruses (HPV) is well known in the context of cervical carcinoma; however, their role in the development of oesophageal squamous cell carcinoma (OSCC) is less clear. We aimed to determine the extent of the association between HPV infection and OSCC. A comprehensive literature search found 132 studies addressing HPV and OSCC in human cases, and a meta-analysis was performed using a random-effects model. There was evidence of an increased risk of OSCC in patients with HPV infection [odds ratio (OR) 2·69, 95% confidence interval (CI) 2·05-3·54]. The prevalence of HPV in OSCC was found to be 24·8%. There was an increased risk associated with HPV-16 infection (OR 2·35, 95% CI 1·73-3·19). Subgroup analyses showed geographical variance, with Asia (OR 2·94, 95% CI 2·16-4·00), and particularly China (OR 2·85, 95% CI 2·05-3·96) being high-risk areas. Our results confirm an increase in HPV infection in OSCC cases.

Prevalence of human papillomavirus among oesophageal squamous cell carcinoma cases: systematic review and meta-analysis

Background:

Oncogenic human papillomavirus (HPV) has been hypothesised as a risk factor for oesophageal squamous cell carcinoma (OSCC), but aetiological research has been limited by the varying methodology used for establishing HPV prevalence. The aims of this systematic review and meta-analysis were to estimate the prevalence of HPV DNA detected in OSCC tumours and the influence of study characteristics.

Methods:

Study-level estimates of overall and type-specific HPV prevalence were meta-analysed to obtain random-effects summary estimates.

Results:

This analysis included 124 studies with a total of 13 832 OSCC cases. The average HPV prevalence (95% confidence interval) among OSCC cases was 0.277 (0.234, 0.320) by polymerase chain reaction; 0.243 (0.159, 0.326) by in situ hybridisation; 0.304 (0.185, 0.423) by immunohistochemistry; 0.322 (0.154, 0.490) by L1 serology; and 0.176 (0.061, 0.292) by Southern/slot/dot blot. The highest HPV prevalence was found in Africa and Asia, notably among Chinese studies from provinces with high OSCC incidence rates.

Conclusions:

Future research should focus on quantifying HPV in OSCC cases using strict quality control measures, as well as determining the association between HPV and OSCC incidence by conducting large, population-based case–control studies. Such studies will provide a richer understanding of the role of HPV in OSCC aetiology.

Prevalence of human papillomavirus infection in esophageal and cervical cancers in the high incidence area for the two diseases from 2007 to 2009 in Linzhou of Henan Province, Northern China

The etiological role of human papillomavirus (HPV) in cervical cancer has been well established. However, it is inconclusive whether HPV plays the same role in esophageal carcinogenesis. In this study, we detected HPV infection in 145 frozen esophageal tissues, including 30 normal epithelium (ENOR), 37 dysplasia (DYS) and 78 invasive squamous cell carcinoma (ESCC), and in 143 frozen cervical tissues composed of 30 normal epithelium (CNOR), 38 intraepithelial neoplasia (CIN) and 75 invasive squamous cell carcinoma (CSCC). The patients and symptom-free subjects enrolled in this study were from a high-incidence area for both ESCC and CSCC, Linzhou City, Northern China, from 2007 to 2009. The HPV infection analysis was conducted by using an HPV GenoArray Test Kit. We found that the high-risk HPV types accounted for more than 90 % of the HPV-positive lesions of esophagus and cervix tissues. The prevalence of high-risk HPV types increased significantly during the progression of both esophageal and cervical carcinogenesis (positive rate in esophageal tissues: 33 % ENOR, 70 % in DYS and 69 % in ESCC; positive rate in cervical tissues: 27 % in CNOR, 82 % in CIN and 88 % in CSCC; P < 0.001, respectively). Infection with the high-risk HPV types increased the risk for both DYS and ESCC by 4-fold (DYS vs. ENOR: OR = 4.73, 95 %CI = 1.68-13.32; ESCC vs. ENOR: OR = 4.50, 95 %CI = 1.83-11.05) and increased the risk for both CIN and CSCC by 12-fold and 20-fold (CIN vs. CNOR: OR = 12.18, 95 %CI = 3.85-38.55; CSCC vs. CNOR: OR = 20.17, 95 %CI = 6.93-58.65), respectively. The prevalence of high-risk types in ESCC patients was lower than that in CSCC patients (P = 0.005) and was significantly associated with the degree of ESCC tumor infiltration (P = 0.001). HPV 16 was the most prevalent subtype in both esophageal and cervical tissues. Single HPV infection increased significantly along with the progression of ESCC and maintained a high level in cervical tissues, regardless of whether they were CNOR or CSCC tissues. Our results showed that infection with HPV, especially the high-risk types, was positively associated with both esophageal and cervical cancers, suggesting that HPV also plays a role in the etiology of ESCC in the high-incidence area.

Human papillomavirus types 16 and 18 in esophagus squamous cell carcinoma: a meta-analysis

PURPOSE

A possible carcinogenic role of human papillomavirus (HPV) has been investigated in esophageal squamous cell carcinoma (ESCC) for nearly 30 years with mixed results. We performed a meta-analysis to assess the prevalence of "high-risk" HPV, HPV-16/18, in this disease. We also evaluated the association between infection with HPV-16/18 and ESCC risk by meta-analysis of case-control studies.

METHODS

Eligible studies published up to September 30, 2012 were retrieved via both computer searches of MEDLINE and EMBASE and manual review of references. A random-effects model was used to calculate summary prevalence and odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 5755 cases of ESCC from 68 studies were included in this meta-analysis. Overall, 11.67% (95% CI, 7.74%-16.21%) of ESCC cases harbored HPV-16 and 1.82% (95% CI, 0.90%-2.95%) harbored HPV-18. In addition, meta-analysis of 10 case-control studies showed a significant increase in ESCC risk with HPV-16 infection (summary ORs = 3.55; 95% CIs, 2.05%-6.14%). However, this increased risk in ESCC was not made for HPV-18 infection (summary ORs = 1.25; 95% CIs, 0.46%-3.43%).

CONCLUSIONS

This meta-analysis indicated that HPV-16 and -18 can be detected in ESCC. HPV-16, but not HPV-18, is significantly associated with the risk of ESCC. However, it is early to conclude that both types of HPV are involved in esophageal carcinogenesis.

The role of inflammation in HPV infection of the Oesophagus

BACKGROUND

Several human cancers are known to be associated with inflammation and/or viral infections. However, the influence of tumour-related inflammation on viral uptake is largely unknown. In this study we used oesophageal squamous cell carcinoma (OSCC) as a model system since this type of cancer is associated with chronic irritation, inflammation and viral infections. Although still debated, the most important viral infection seems to be with Human Papillomavirus (HPV). The present study focused on a possible correlation between inflammation, OSCC development and the influence of HPV infection.

METHODS

A total of 114 OSCC biopsies and corresponding normal tissue were collected at Groote Schuur Hospital and Tygerberg Hospital, Cape Town (South Africa), that were subjected to RNA and DNA isolation. RNA samples were analysed by quantitative Light Cycler RT-PCR for the expression of selected genes involved in inflammation and infection, while conventional PCR was performed on the DNA samples to assess the presence of integrated viral DNA. Further, an in vitro infection assay using HPV pseudovirions was established to study the influence of inflammation on viral infectivity using selected cell lines.

RESULTS

HPV DNA was found in about 9% of OSCC patients, comprising predominantly the oncogenic type HPV18. The inflammatory markers IL6 and IL8 as well as the potential HPV receptor ITGA6 were significantly elevated while IL12A was downregulated in the tumour tissues. However, none of these genes were expressed in a virus-dependent manner. When inflammation was mimicked with various inflammatory stimulants such as benzo-α-pyrene, lipopolysaccharide and peptidoglycan in oesophageal epithelial cell lines in vitro, HPV18 pseudovirion uptake was enhanced only in the benzo-α-pyrene treated cells. Interestingly, HPV pseudovirion infectivity was independent of the presence of the ITGA6 receptor on the surface of the tested cells.

CONCLUSION

This study showed that although the carcinogen benzo-α-pyrene facilitated HPV pseudovirion uptake into cells in culture, HPV infectivity was independent of inflammation and seems to play only a minor role in oesophageal cancer.

Viral load of HPV 16/18 in esophageal squamous cell carcinoma in three ethnic groups living in Xinjiang Autonomous Region, China

To investigate the viral load of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) patients from three ethnic groups in Xinjiang. Using Gp5+/Gp6+ consensus primers, the prevalence of HPV DNA was examined in 253 paraffin-embedded ESCC samples. The presence and viral load of HPV 16 and HPV 18 were detected in Kazakhs, Uygurs and Hans using type-specific primers by quantitative real-time PCR (qRT-PCR). Among the 253 ESCC samples, 52 cases were positive for HPV DNA, all the 52 positive cases displayed HPV 16 infection, and six of the 52 cases were co-infected by HPV 16 and 18. HPV 16-positive rate and viral load were higher in lesions, and was inversely correlated with differentiation grades. However, there was no statistic significance among different differentiation grades. Also, there were no significant difference between detection rates of HPV types, viral load and age, gender, ethnic group, and lymph node metastasis. HPV 16 and HPV 18 genotypes could simultaneously be detected in ESCC specimens in three main ethnic groups in Xinjiang. The viral load of HPV 16 is higher in the ESCC lesions, and is inversely correlated with the differentiation grades. These observations reinforce the suggestion that HPV infection may involved in ESCC carcinogenesis; however, high prevalence or viral load of HPV infection does not seem to be related with high incidence of ESCC in Kazakhs, which may be the one element among the multiple risk factors contributing to ESCC.

Incidence of human papilloma virus in esophageal squamous cell carcinoma in patients from the Lublin region

AIM: To assess the prevalence of human papilloma virus (HPV) in esophageal squamous cell carcinoma (ESCC) in the south-eastern region of Poland.

METHODS: The study population consisted of 56 ESCC patients and 35 controls. The controls were patients referred to our department due to other non-esophageal and non-oncological disorders with no gross or microscopic esophageal pathology as confirmed by endoscopy and histopathology. In the ESCC patients, samples were taken from normal mucosa (56 mucosa samples) and from the tumor (56 tumor samples). Tissue samples from the controls were taken from normal mucosa of the middle esophagus (35 control samples). Quantitative determination of DNA was carried out using a spectrophotometric method. Genomic DNA was isolated using the QIAamp DNA Midi Kit. HPV infection was identified following PCR amplification of the HPV gene sequence, using primers MY09 and MY11 complementary to the genome sequence of at least 33 types of HPV. The sequencing results were computationally analyzed using the basic local alignment search tool database.

RESULTS: In tumor samples, HPV DNA was identified in 28 of 56 patients (50%). High risk HPV phenotypes (16 or/and 18) were found in 5 of 56 patients (8.9%), low risk in 19 of 56 patients (33.9%) and other types of HPV (37, 81, 97, CP6108) in 4 of 56 patients (7.1%). In mucosa samples, HPV DNA was isolated in 21 of 56 patients (37.5%). High risk HPV DNA was confirmed in 3 of 56 patients (5.3%), low risk HPV DNA in 12 of 56 patients (21.4%), and other types of HPV in 6 of 56 patients (10.7%). In control samples, HPV DNA was identified in 4 of 35 patients (11.4%) with no high risk HPV. The occurrence of HPV in ESCC patients was significantly higher than in the controls [28 of 56 (50%) vs 4 of 35 (11.4%), P < 0.001]. In esophageal cancer patients, both in tumor and mucosa samples, the predominant HPV phenotypes were low risk HPV, isolated 4 times more frequently than high risk phenotypes [19 of 56 (33.9%) vs 5 of 56 (8.9%), P < 0.001]. A higher prevalence of HPV was identified in female patients (71.4% vs 46.9%). Accordingly, the high risk phenotypes were isolated more frequently in female patients and this difference reached statistical significance [3 of 7 (42.9%) vs 2 of 49 (4.1%), P < 0.05]. Of the pathological characteristics, only an infiltrative pattern of macroscopic tumor type significantly correlated with the presence of HPV DNA in ESCC samples [20 of 27 (74.1%) vs 8 of 29 (27.6%) for ulcerative or protruding macroscopic type, P < 0.05]. The occurrence of total HPV DNA and both HPV high or low risk phenotypes did not significantly differ with regard to particular grades of cellular differentiation, phases in depth of tumor infiltration, grades of nodal involvement and stages of tumor progression.

CONCLUSION: Low risk HPV phenotypes could be one of the co-activators or/and co-carcinogens in complex, progressive, multifactorial and multistep esophageal carcinogenesis.

Role of human papillomaviruses in esophageal squamous cell carcinoma

Esophageal cancer (EC) is responsible for almost half a million deaths worldwide annually and has a multifactorial etiology, which may account for its geographical variation in incidence. In the last 30 years the potential of human papillomaviruses (HPV) as oncogenes or co-factors in the tumorigenic process of esophageal squamous cell carcinoma (ESCC) has been widely studied. While the etiology of HPV in cervical and certain other anogenital and aerodigestive cancers has been established, results regarding its role in EC have been largely inconclusive. A causal association can be evaluated only with a case-control study, where normal controls are compared to ESCC cases for the presence of HPV. We reviewed all studies investigating ESCC tissue for HPV DNA and identified 139 that met our inclusion criteria, of which only 22 were case-control studies. Our results support previous findings of higher levels of HPV detection in high-risk ESCC regions than in areas of low risk. In addition, we confirm that the role of HPV in ESCC remains unclear, despite an accumulation of studies on the subject. The variations in investigative technique, study design and sample types tested may account for the lack of consistency in results. There is a need for a meta-analysis of all case-control studies to date, and for large, well-designed case-control studies with adequate power to investigate the association. The potential benefits of prophylactic HPV vaccines could be evaluated if HPV is identified as an etiological factor in EC, highlighting the need for further research in this area.

Geographic origin is a significant determinant of human papillomavirus prevalence in oesophageal squamous cell carcinoma: systematic review and meta-analysis

BACKGROUND

Since the first reports in 1982 suggesting an aetiological role for human papillomavirus (HPV) in a subset of oesophageal squamous cell carcinomas (ESCC), the literature reporting HPV detection in ESCC has expanded rapidly. However no formal meta-analysis of this literature has been published yet. The objective of this study was to perform a systematic review and formal meta-analysis of the literature reporting HPV detection in ESCC.

METHODS

MEDLINE and Current Contents were searched through March 2012. The effect size was calculated as event rates and their 95% confidence interval (95% CI), with homogeneity testing using Cochran's Q and I² statistics. Meta-regression was used to test the impact of study-level covariates (HPV detection method, geographic origin of study) on effect size, and potential publication bias was estimated using funnel plot symmetry (Begg and Mazumdar rank correlation, Egger's regression, and Duval and Tweedie's trim and fill method).

RESULTS

Of the 1177 abstracts found, 152 studies were determined to be eligible for this meta-analysis. These 152 studies covered a total of 10,234 ESCC cases, analysed by different HPV detection methods in different geographic regions. Of these 10,234 cases, 3135 (30.6%) tested HPV-positive, translating to an effect size of 0.372 (95% CI 0.360-0.384; fixed effects model) and 0.290 (95% CI 0.251-0.31; random effects model). When stratified by HPV detection technique, there was a significant heterogeneity between the studies, but importantly, the between-strata summary comparison was not significant (random effects model; p = 0.440). In contrast, there was significant heterogeneity between the studies from the different geographic regions. In the maximum likelihood meta-regression, HPV detection method was not a significant study-level covariate, in contrast to the geographic origin of the study, which had a significant impact (p = 0.00005) on the summary effect size estimates. No evidence for significant publication bias was found in funnel plot symmetry testing. In the sensitivity analysis, all meta-analytic results appeared robust to all (n = 151) one-by-one study removals.

CONCLUSIONS

These meta-analysis results indicate that the reported wide variability in HPV detection rates in ESCC is not due to the HPV detection techniques, but is explained by the geographic origin of the study. These data substantiate the recently elaborated concept that ESCC might have a different aetiology in low-incidence and high-incidence geographic regions, HPV playing an important role only in the latter.

Human papillomavirus in upper digestive tract tumors from three countries

AIM: To clarify human papillomavirus (HPV) involvement in carcinogenesis of the upper digestive tract of virological and pathological analyses.

METHODS: The present study examined the presence of HPV in squamous cell carcinomas of the oral cavity (n = 71), and esophagus (n = 166) collected from Japan, Pakistan and Colombia, with different HPV exposure risk and genetic backgrounds. The viral load and physical status of HPV16 and HPV16-E6 variants were examined. Comparison of p53 and p16^INK4a expression in HPV-positive and HPV-negative cases was also made.

RESULTS: HPV16 was found in 39 (55%) oral carcinomas (OCs) and 24 (14%) esophageal carcinomas (ECs). This site-specific difference in HPV detection between OCs and ECs was statistically significant (P < 0.001). There was a significant difference in the geographical distribution of HPV16-E6 variants. Multiple infections of different HPV types were found in 13 ECs, but multiple infections were not found in OCs. This difference was statistically significant (P = 0.001). The geometric means (95% confidence interval) of HPV16 viral load in OCs and ECs were 0.06 (0.02-0.18) and 0.12 (0.05-0.27) copies per cell, respectively. The expression of p16^INK4a proteins was increased by the presence of HPV in ECs (53% and 33% in HPV-positive and -negative ECs, respectively; P = 0.036), and the high-risk type of the HPV genome was not detected in surrounding normal esophageal mucosa of HPV-positive ECs.

CONCLUSION: Based on our results, we cannot deny the possibility of HPV16 involvement in the carcinogenesis of the esophagus.

Infection and integration of human papillomavirus in esophageal carcinoma

Infection with human papillomavirus (HPV) could be a suspected or potential modifiable risk factor in esophageal carcinoma (EC) but findings have not been consistent. We therefore investigated the epidemiology of HPV infection and integration in the pathogenesis of esophageal carcinoma (EC) in the Shantou region, China. This was a retrospective study involving nested PCR to evaluate HPV presence, HPV genotyping, and analyzing HPV-16 integration status in esophageal tumor tissues (n=106) and paired tumor-adjacent normal tissues, as well as normal esophagus tissue from control subjects (n=100). The detection rates of HPV DNA in EC and tumor-adjacent tissue were significantly higher than that in normal controls (77.4% and 80.2% vs. 33.0%). HPV infection was mainly found in adults, ages 35-47 years old, and the infection rate was negatively associated with the age of EC patients (P-trend<0.05). In addition, the HPV infection rates in patients who smoked was 3.27 times higher than in non-smoking patients (84.9% vs. 67.4%, P<0.05) but was not associated with gender, alcohol consumption, tumor grade or lymph-node metastasis of EC patients. The distribution of HPV genotypes in patients from high to low proportion was HPV-16, -58, -18, -33, -31 and -11. Infection with multiple HPV genotypes mainly included HPV-16/-18 and HPV-16/-33. The integration rate of HPV-16 in EC tissue was higher than that in tumor-adjacent and control tissues (93.4% vs. 50.9% and 45.5%). Our findings indicate that infection with HPV, especially the high-risk HPV, and their integration suggest an association in malignant transformation of EC in the high-incidence EC region in Shantou, China.

High-risk human papillomavirus in esophageal squamous cell carcinoma

BACKGROUND

Although most cases of esophageal squamous cell carcinoma (ESCC) in western populations have been attributed to high levels of exposure to tobacco and alcohol, infectious agents have been postulated as possible causes, particularly human papillomavirus (HPV).

METHODS

To explore this issue, we analyzed HPV DNA prevalence and HPV types together with lifestyle factors, in relation to tumor stage and survival in a low-incidence population. Archived tumor samples from a nationwide cohort of 222 ESCC patients were tested for the presence of HPV DNA by PCR; positive samples were sequenced to determine HPV type, and p16(INK4a) status was assessed by immunohistochemistry.

RESULTS

Of 222 ESCC patients, 8 tested HPV positive (prevalence, 3.6%; 95% confidence interval, 1.1-6.1%), of which 6 were HPV-16 positive and 2 were HPV-35 positive. Four of the eight HPV-positive tumors overexpressed p16(INK4a). None of 55 normal esophageal tissue samples from healthy participants had any detectable HPV. Although the numbers were low, it seemed that patients with HPV-positive ESCC tumors were younger than those with HPV-negative tumors (mean age, 60.8 versus 65.3 years, P = 0.18) and had higher body mass index (BMI) throughout life (mean current BMI of 25.1 for HPV positive, 22.2 for HPV negative, P = 0.08; mean BMI at 20 years of 25.8 for HPV positive, 22.1 for HPV negative, P = 0.003). We found no difference between patients with HPV-positive and HPV-negative tumors with respect to other lifestyle factors.

CONCLUSIONS

These findings suggest a very low prevalence of HPV DNA in human ESCC.

IMPACT

HPV is very unlikely to be a common cause of ESCC in Australia.

Comparison of prevalence, viral load, physical status and expression of human papillomavirus-16, -18 and -58 in esophageal and cervical cancer: a case-control study

BACKGROUND

Human papillomavirus (HPV) infection is a major risk factor for the development of nearly all cases of cervical cancer worldwide. The presence of HPV DNA in cases of esophageal squamous-cell carcinoma (ESCC) has been reported repeatedly from Shantou, China, and other regions with a high incidence of esophageal carcinoma (EC). However, unlike in cervical squamous-cell carcinoma (CSCC), in ESCC, the characteristics of HPV are unclear. Thus, the role of high-risk HPV types in the carcinogenesis of ESCC remains uncertain.

METHODS

Seventy cases of ESCC with 60 controls and 39 cases of CSCC with 54 controls collected from patients in Shantou region in China were compared for the distributions of HPV-16, -18 and -58; viral load; and viral integration using real-time PCR assay and HPV-16 expression using immunostaining.

RESULTS

The detection rates and viral loads of HR-HPV infection were significantly lower in ESCC than in CSCC (50.0% vs. 79.48%, P = 0.005; 2.55 ± 3.19 vs. 361.29 ± 441.75, P = 0.002, respectively). The combined integration level of HPV-16, -18 and -58 was slightly lower in ESCC than in CSCC (P = 0.022). HPV-16 expression was detected in 59.26% of ESCC tissue and significantly associated with tumour grade (P = 0.027).

CONCLUSIONS

High levels of HR-HPV expression and integration may be an indicator of the risk of ESCC, at least for patients in the Shantou region of China. However, a relatively low HPV copy number and infection rate in ESCC is unlikely to play an essential a role in the carcinogenesis of ESCC as in cervical cancer. Factors other than HR-HPV infection may contribute to the carcinogenesis of ESCC.

No role for human papillomavirus in esophageal squamous cell carcinoma in China

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically-confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh-frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type-specific E6 and E7 primers, and in formalin-fixed paraffin-embedded tumor tissue using SPF(10) L1 primers. In HPV-positive cases, we evaluated p16(INK4a) overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. beta-globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9-100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6-100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin-fixed paraffin-embedded tumor specimens, 99.3% (95% CI = 97.3-99.9%) were HPV negative by SPF(10). By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF(10), 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA-positive case had evidence of HPV oncogene activity as measured by p16(INK4a) overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.

Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: implications for carcinogenesis

Ectopic expression of viral oncoproteins disrupts cellular functions and limits the value of many existing immortalization models as models for carcinogenesis, especially for cancers without definitive viral etiology. Our newly established telomerase-immortalized human esophageal epithelial cell line, NE2-hTERT, retained nearly-diploid and non-tumorigenic characteristics, but exhibited genetic and genomic alterations commonly found in esophageal cancer, including progressive loss of the p16(INK4a) alleles, upregulation of anti-apoptotic proteins, epithelial-mesenchymal transition, whole-chromosome 7 gain and duplicated 5q arm. Our data also revealed a novel positive regulation of p16(INK4a) on cyclin D1. These findings probably represent early crucial events and mechanisms in esophageal carcinogenesis.

Detection of HPV DNA in esophageal cancer specimens from different regions and ethnic groups: a descriptive study

Background

HPV has been found repeatedly in esophageal carcinoma tissues. However, reported detection rates of HPV DNA in these tumors have varied markedly. Differences in detection methods, sample types, and geographic regions of sample origin have been suggested as potential causes of this discrepancy.

Methods

HPV L1 DNA and HPV genotypes were evaluated in 435 esophageal carcinoma specimens collected from four geographic regions with different ethnicities including Anyang in north China, Shantou in south China, Xinjiang in west China, and the United States. The HPV L1 fragment was detected using SPF1/GP6+ primers. HPV genotyping was performed using genotype specific PCR.

Results

Two hundred and forty four of 435 samples (56.1%) tested positive for HPV L1. Significant differences in detection rate were observed neither among the three areas of China nor between China and the US. HPV6, 16, 18, 26, 45, 56, 57, and 58 were identified in L1 positive samples. HPV16 and 57 were the most common types in all regions, followed by HPV26 and HPV18.

Conclusions

HPV infection is common in esophageal carcinoma independent of region and ethnic group of origin. Findings in this study raise the possibility that HPV is involved in esophageal carcinogenesis. Further investigation with a larger sample size over broader geographic areas may be warranted.

Relationship between human papillomavirus 16 and esophageal squamous cell carcinoma in Uygur population in Xinjiang Uygur Autonomous Region

AIM: To investigate the infection rate of human papillomavirus 16 (HPV16) in Uygur patients with esophageal squamous cell carcinoma in Xinjiang.

METHODS: Eighty-two paraffin-embedded specimens of esophageal carcinoma and 80 tumor-adjacent specimens were used in the study. The presence of HPV16 in these specimens was detected by high-sensitivity polymerase chain reaction (PCR) using the type-specific E6 primers.

RESULTS: The infection rates of HPV16 in esophageal squamous cell carcinoma and tumor-adjacent tissue were 31.7% (26/82) and 12.5% (10/80), respectively, showing significant difference between the two groups. HPV16 infection was not correlated with patient's age and sex as well as pathological differentiation and clinical stage of the carcinoma (χ² = 0.301, 0.149, 2.876 and 0.105, respectively; all P > 0.05).

CONCLUSION: HPV 16 infection is possibly correlated with esophageal squamous cell carcinoma in Uygur population in Xinjiang but showed no correlation with patient's age and sex as well as pathological differentiation and clinical stage of the carcinoma.

Meta-analysis of relationship between tumorigenesis of esophageal carcinoma and human papillomavirus infection

AIM: To synthetically evaluate the relationship between human papillomavirus (HPV) infection and the tumorigenesis of esophageal carcinoma.

METHODS: Research articles about HPV infection and the development of esophageal carcinoma were collected from journals published from Jan 1987 to Nov 2008. The searching criteria included all randomized evidence for HPV DNA detection with polymerase chain reaction (PCR) or in situ hybridization (ISH). Meta-analysis was performed to re-analyze those references synthetically.

RESULTS: A total of 15 trials including 1174 esophageal carcinoma patients and 988 normal controls were collected. Meta-analysis revealed that the combined odds ratios (ORc) for HPV infection in esophageal carcinoma was 4.29 (95%CI: 2.38-7.70) times higher than that of normal esophagus mucosa. The mean positive rates for HPV infection in esophageal carcinoma and normal esophageal mucosa tissues were both significantly higher in areas with high prevalence than in areas with low prevalence (59.26% vs 34.66%, χ² = 66.05, P < 0. 001; 42.50% vs 15.82%, χ² = 66.02, P < 0. 001).

CONCLUSION: HPV infection increases the risk of tumorigenesis of esophageal carcinoma, especially in areas with high prevalence of esophageal carcinoma in China.

Relationship between HPV6b infection and esophageal cancer in Kazakh in Xinjiang Uygur Autonomous Region

AIM: To evaluate the association between HPV6b infection and esophageal cancer (EC) in Kazakh of Xinjiang, China.

METHODS: A case-control study was conducted with 120 cases of EC and 120 controls. The controls were matched by sex, nationality, area of residence and age difference within 5 years. HPV6b infection was identified by PsV neutralization assay from blood-serum. Chi-square was performed to identify risk factors.

RESULTS: The esophageal cancer infection rate was 27.5% in the cases while it was 22.5% in the controls. Infection rate of esophageal cancer in experiment group was not statistically different from the controls (χ² = 0.80, P = 0.371). HPV6b infection rate of the males was not statistically different from the females in both the cases and the controls (χ² = 0.31, 0.01, P = 0.58, 0.92). The infection rates of HPV6b in < 50, 50-59, 60-69 and ≥ 70 age groups, were 31.0%, 29.0%, 20.9% and 35.3%, respectively with no statistical differences detected among these groups in EC group (χ² = 1.67, P = 0.64). The infection rates of HPV6b were 19.4%, 13.5%, 30.6% and 31.3%, respectively in the controls with no statistical differences either (χ² = 3.93,P = 0.27).

CONCLUSION: The infection of HPV6b is common. The EC in Kazakh of Xinjiang has no association with HPV6b infection.

No association of high-risk human papillomavirus with esophageal squamous cell carcinomas among Koreans, as determined by polymerase chain reaction

The incidence of esophageal squamous cell carcinoma varies greatly with race and geographic location. It has been suggested that human papillomavirus (HPV) is involved in the pathogenesis of esophageal cancers, and that the incidence of esophageal cancers associated with HPV depends on the geographic location of the patient population. In studies performed on tumor specimens collected from areas with a low incidence of esophageal squamous cell carcinomas, HPV infection was detected in only a small percentage of tumors, whereas studies performed on specimens obtained from areas with a high incidence of esophageal squamous cell carcinomas provided strong evidence that HPV plays a significant role in esophageal carcinogenesis. To elucidate the putative role of HPV infection in the etiology of esophageal cancer in Korea, a total of 129 formalin-fixed, paraffin-embedded tumor specimens, eight fresh tumor tissues and 40 normal esophageal tissues were screened for HPV infection by polymerase chain reaction using consensus primers for HPV types 16, 18, 31, 33, 35, 52b and 58 and type 16-specific primers. SiHa cell line, formalin-fixed, paraffin-embedded cervical squamous cell carcinoma specimens were used as positive controls for HPV infection. Fragments of human beta-globin gene, which served as the internal controls, were successfully amplified from 102 of the 129 cancer specimens and from all the normal and fresh cancer tissues, while consensus and type 16-specific primers failed to detect HPV DNA sequences in any of the esophageal samples. The DNA extracted from the SiHa cell line and uterine cervical cancers were positive when both the consensus and type-specific primers were used. The results of this study suggest that HPV is not associated with esophageal carcinogenesis in Korea.

Human papillomavirus is a favourable prognostic factor in tonsillar cancer and its oncogenic role is supported by the expression of E6 and E7

From 1970 to 2002 in the Stockholm area, we revealed a parallel three-fold increase in the incidence of tonsillar cancer and the proportion of human papillomavirus (HPV) positive tonsillar cancer cases, indicating a possible role of HPV infection in this disease. We have now examined whether HPV and viral load in pre-treatment tonsillar cancer biopsies correlates to disease prognosis, and whether the presence of HPV-16 E6 and E7 mRNA could be ascertained. The presence of HPV-16, but not viral load, in tonsillar cancer was shown to be a favourable prognostic factor for clinical outcome. Moreover, E6 and/or E7 were expressed in almost all assessable HPV-16 positive cases, supporting an oncogenic role of HPV-16 in tonsillar cancer.

Human papillomavirus in high- and low-risk areas of oesophageal squamous cell carcinoma in China

To examine the potential roles of human papillomavirus (HPV) in oesophageal squamous cell carcinoma (ESCC) development, we examined the presence of HPV DNA in paraffin-embedded ESCC tissues collected from two areas with different ESCC incidence rates in China, that is, Gansu (n=26) and Shandong (n=33), using PCR with SPF10 primers, or PCR with GP5+/GP6+ primers combined with Southern blot hybridisation. HPV genotype was determined by the INNO-LiPA HPV genotyping kit. HPV DNA was detected in 17 cases (65%) in Gansu, where ESCC incidence is much higher than in Shandong, where HPV was positive in two samples (6%). HPV genotypes 16 and 18 were detected in 79 and 16% of HPV-positive samples, respectively. Real-time PCR analysis suggested the presence of integrated form of HPV DNA in all the HPV-16-positive samples, but its viral load was estimated to be only <1–2 copies cell⁻¹. We could not detect HPV 16/18 E6 protein expression by immunostaining in any of the HPV-16-positive samples. Neither p16^INK4a nor p53 expression was related to HPV presence in ESCCs. Further studies seem warranted to examine the possible aetiological roles of HPV in ESCC.

Unique expression of human papilloma virus type 5 and type 16 in esophageal squamous cell carcinoma-a case report

The role of human papilloma virus (HPV) in esophageal cancers from the low-incidence area (Western population) is unclear. We report a case of esophageal squamous papillomatosis associated with underlying esophageal squamous cell carcinoma (OSCC). The esophagectomy specimen confirmed presence of HPV-5 and HPV-16 suggesting a viral etiology. The significance of this dual infection is not known, but it suggests that esophageal papillomatosis is premalignant and should receive regular endoscopic follow-up. This is the first report of both HPV-5 and HPV-16 DNA detected in an esophageal cancer occurring in the Western population.

High-risk human papilloma virus (HPV) and survival in patients with esophageal carcinoma: a pilot study

BACKGROUND

Human papilloma virus (HPV) in patients with esophageal carcinoma has previously been studied with an average detection rate of 15%, but the role of HPV in relation to survival is less clear. In cervical cancer, lung cancer and tonsil cancer HPV viral load is a predictive factor for survival and outcome of treatment. The primary aim was to study the spectrum of high-risk HPV types in esophageal tumors. Secondary, as a pilot study we investigated the association between HPV status and the survival rates.

METHODS

We compared both the presence and the viral load of high-risk HPV types 16, 18, 31, 33, 39, 45, 52, 58, and 67 in relation to clinical data from patients with esophageal carcinoma. Survival data and tumor samples were retrieved from 100 patients receiving treatment at the Department of Oncology, Uppsala Hospital, Uppsala, Sweden. The tumor samples were investigated for HPV viral load using real-time PCR.

RESULTS

HPV 16 was detected in 16% of the patients; no other HPV type was detected. HPV 16 infection had no significant effect on survival (p = 0.72). Also, HPV 16 did not improve survival after treatment (radiotherapy or chemotherapy).

CONCLUSION

Only HPV 16 was detected among the patients. HPV 16 in esophageal carcinoma patients did not influence survival or improve therapy response. However, given the size of the study there is a need to examine a larger cohort in order to understand in more detail the effect of high risk HPV types in esophageal carcinoma.

Detection of human papillomavirus DNA in squamous cell carcinoma of the esophagus by auto-nested PCR

The aim of the present study was to investigate the presence of human papillomavirus (HPV) in surgical specimens of esophageal squamous cell carcinoma. One hundred and sixty-five paraffin-embedded specimens of esophageal carcinoma were analyzed through high-sensitivity auto-nested polymerase chain reaction (PCR) using the consensus GP5+/GP6+ primer. Twenty-six specimens of esophageal mucosa without malignant disease were also studied as a control group. Two different specific primer sets targeting the E6 region of the HPVs 16 and 18 were used for typing. Direct DNA sequence analysis was conducted to confirm positive PCR results. HPV DNA was detected in 26 esophageal carcinomas (15.75%), but in none of the benign esophageal specimens (P < 0.05). Out of the 26 positive cases, 24 were HPV-16 and one was HPV-18. One tumor contained both HPV-16 and -18 DNA. Positive PCR results were confirmed by the amplified viral sequences. Our findings suggest that the presence of either HPV-16 or -18 might be related to development of the malignant phenotype in the esophagus.

Papillomavirus type 16 E6/E7 and human telomerase reverse transcriptase in esophageal cell immortalization and early transformation

Infection with high-risk human papillomavirus (HPV) has been implicated in the pathogenesis of esophageal squamous cell carcinoma, and up-regulation of telomerase in esophageal adenocarcinoma. We immortalized normal esophageal epithelial cells by over-expression of the HPV16 E6/E7 and human telomerase reverse transcriptase (hTERT) genes. HPV16 E6/E7-induced immortalization was accompanied by reduced RB and p53, but increased p16 and p21, protein expression. hTERT-immortalized cells had unaffected RB and p53, but significantly decreased p16 and p21, protein expression. Aurora-A protein was also up-regulated in E6E7 immortalized cells, and to a less extent in hTERT immortalized cells. Fluorescence in situ hybridization showed that the Aurora-A gene locus was amplified in E6E7 immortalized cells, which might account in part for the Aurora-A over-expression. These molecular changes led to an abrogation of the G2 checkpoint. E6E7 and hTERT immortalized esophageal cells recapitulated many of the molecular changes observed in esophageal carcinomas, where RB and p53 are frequently down-regulated. However, down-regulation of p16 and p21 occurred frequently in esophageal cancer, owing to aberrant gene promoter methylation. We showed in the immortalized cells that aberrant methylation had not yet set in, suggesting that promoter methylation might not be necessary for cellular immortalization. In addition to supporting the role of HPV and telomerase in esophageal carcinogenesis, our cell lines may also be useful in vitro models for further studies of esophageal carcinogenesis.

Early integration of high copy HPV16 detectable in women with normal and low grade cervical cytology and histology

BACKGROUND

Integration of human papillomavirus (HPV) DNA has been considered a late event in cervical carcinogenesis. However, integrated forms of HPV were recently detected in cancer precursor lesions using a new real time polymerase chain reaction (PCR) to detect the deletions at the 3362-3443 region of HPV16 E2 OBJECTIVE: To study the frequency of HPV16 DNA integration in cervical lesions and compare the sensitivity of an additional upstream region of the E2 ORF (2962-3138) in detecting HPV integration.

METHODS

Using the TaqMan based PCR, HPV16 positive DNA samples were analysed in 164 cervical scrapings from women participating in a multicentre screening trial. Biopsy confirmation was available in 62 cases.

RESULTS

Primers targeting the 3362-3443 region detected the majority of E2 deletions. In only 23% of the samples was the E2 upstream region equal or better target than the 3362-3443 region. Mixed (episomal/integrated) pattern was the most prevalent physical state of HPV16, also present in PAP smears with normal morphology. Pure integrated form was most prevalent in HSIL and cancer lesions, but also detectable in low grade abnormalities (NSIL, ASC-US, LSIL). Women with only integrated HPV16 were almost 10 years older than those with episomal HPV16. Viral load of integrated HPV16 was related to cytological abnormality (p = 0.003) but not to histology.

CONCLUSIONS

Integrated HPV16 is present in low grade cervical lesions, mostly mixed with the episomal form. Women with the pure integrated form of HPV16 are older than those with the other forms.

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Immune response in cervical dysplasia induced by human papillomavirus: the influence of human immunodeficiency virus-1 co-infection - review

Human immunodeficiency virus (HIV-1) has become an important risk factor for human papillomavirus (HPV) infection and the development of HPV associated lesions in the female genital tract. HIV-1 may also increase the oncogenicity of high risk HPV types and the activation of low risk types. The Center for Disease Control and Prevention declared invasive cervical cancer an acquired immunodeficiency virus (AIDS) defining illness in HIV positive women. Furthermore, cervical cancer happens to be the second most common female cancer worldwide. The host's local immune response plays a critical factor in controlling these conditions, as well as in changes in the number of professional antigen-presenting cells, cytokine, and MHC molecules expression. Also, the production of cytokines may determine which arm of the immune response will be stimulated and may influence the magnitude of immune protection. Although there are many studies describing the inflammatory response in HPV infection, few data are available to demonstrate the influence of the HIV infection and several questions regarding the cervical immune response are still unknown. In this review we present a brief account of the current understanding of HIV/HPV co-infection, emphasizing cervical immune response.

Quantitative analysis of herpes simplex virus in cranial nerve ganglia

A susceptible individual exposed to herpes simplex virus (HSV) will develop latent infection in multiple cranial nerve ganglia. There are a few quantitative studies of the viral load within the trigeminal ganglion, but none that investigate other cranial nerve ganglia. In this study, human trigeminal, geniculate, vestibular (Scarpa's) and cochlear (spiral) ganglia were obtained from willed body donors. Real time quantitative polymerase chain reaction (PCR) analysis of the HSV DNA polymerase gene was performed on ipsilateral ganglion sets from the same individual. Viral load, expressed as HSV genomes per 105 cells, was significantly greater in the vestibular ganglion (mean +/- SD, 176705 +/- 255916) than in the geniculate (9948 +/- 22066), cochlear (3527 +/- 9360), or trigeminal (2017 +/- 5578) ganglia. There was not a significant correlation among ganglia from the same individual. The results support the hypothesis that neuronal subpopulations have variable susceptibility to HSV infection.

Physical status of HPV-16 in esophageal squamous cell carcinoma

BACKGROUND

Infection with high-risk human papillomavirus (HPV) has been implicated as one of the risk factors of esophageal squamous cell carcinoma (ESCC). Integration of viral DNA into host genome is essential for carcinogenesis since it promotes disruption of the HPV E2 gene, leading to abnormal expression of E6 and E7 oncoproteins.

OBJECTIVES AND STUDY DESIGN

To investigate the viral integration status of HPV-16 infection in ESCC, 35 HPV-positive ESCC specimens collected from Chinese patients were subject to real-time quantitative PCR for determination of physical status of HPV-16 by analyzing the ratios of E2 to E6 genes.

RESULTS

Our results showed that only 8.6% (3/35) of the HPV-16 positive specimens harbored exclusively the episomal form (i.e. E2/E6 ratio > or = 1), whereas the remaining 91.4% contained either only the integrated form (5.7%, with E2/E6 ratio = 0) or a mixture of episomal and integrated forms of viral molecules (85.7%, with E2/E6 ratios > 0 but < 1). Amongst the 30 cancer specimens carrying mixed integrated and episomal forms, 28 had E2/integrated E6 ratios of less than 1, indicating a predominance of integrated form of viral genes in these lesions.

CONCLUSION

Our finding of frequent integration of viral DNA in the host genome suggests that integration HPV-16 is common in ESCC from Chinese patients and implies that HPV infection may play a role in the pathogenesis of ESCC.

Human papillomavirus infection and loss of heterozygosity in esophageal squamous cell carcinoma

The incidence/mortality rates of esophageal squamous cell carcinoma (ESCC) vary widely in different parts of China. Human papillomavirus (HPV) infection is considered a possible risk factor. Loss of heterozygosity (LOH) analysis on 87 ESCC specimens collected from three different areas of China showed lower frequency of LOH at marker D3S1621 in Linxian, an area with exceptionally high incidence of ESCC but low HPV infection rate. HPV-positive ESCC from Hong Kong, but not Sichuan, had higher frequency of LOH at D5S82 (APC, MCC), D6S497 (p21/Waf-1, HLA) and D13S260 (BRCA2) than HPV-negative samples. Our results suggest that different genetic pathways of carcinogenesis may be associated with geographic differences in risk factors.

Chapter 9: Role of mucosal human papillomavirus in nongenital cancers

Established associations between human papillomavirus (HPV) and lower genital tract cancers provide a framework from which to evaluate a possible pathogenic role for the virus in cancers at nongenital sites. Proposed associations must fit coherently within the context of our current knowledge of the epidemiology and biology of HPV. In this article, insights obtained from studies of the etiologic link between mucosal-type HPV infection and four specific human cancers are described briefly. Specific characteristics, shared among cancers caused by HPV, are then used by extrapolation to discuss possible associations between certain other nongenital cancers and mucosal HPV infections in a manner intended to supplement, and in no way to supplant, the classic Hill criteria for causal inference.