Human papillomavirus infection in Barrett's oesophagus in the UK: an infrequent event

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.

Viral Pathogens in Oesophageal and Gastric Cancer

Tumour virology was born with the discovery by Peyton Rous in 1911 of a filterable agent in chicken cellular extracts that caused neoplasia in healthy chickens. Universally, 20% of all human cancers have a viral aetiology. Viruses are involved at various stages of the carcinogenesis pathway, depending on the viral pathogen, and likely require co-factors. Multiple risk factors have been associated with oesophageal and gastric malignancy, including carcinogenic pathogens. These viruses and bacteria include human papillomavirus (HPV) [oesophageal cancer], Epstein-Barr virus (EBV) [proximal stomach cancer], and Helicobacter pylori (HP) [non-cardia stomach cancer]. Viruses such as EBV have been firmly established as causal for up to 10% of gastric cancers. HPV is associated with 13 to 35% of oesophageal adenocarcinoma but its role is unclear in oesophageal squamous cell carcinomas. The causal relationship between hepatitis B (HBV), cytomegalovirus (CMV), HPV, and John Cunningham (JCV) and gastric neoplasia remains indeterminate and warrants further study. The expression of viral antigens by human tumours offers preventive and therapeutic potential (including vaccination) and has already been harnessed with vaccines for HPV and HBV. Future goals include viral protein-based immunotherapy and monoclonal antibodies for the treatment of some of the subset of EBV and HPV-induced gastro-esophageal cancers.

Human papillomavirus infection in esophageal squamous cell carcinoma and esophageal adenocarcinoma: a concise review

The causal link between high-risk human papillomavirus (hr-HPV) infection and cervical, anogenital, and some oropharyngeal malignancies has been established by both molecular and epidemiological data. The association between HPV and esophageal squamous cell carcinoma (ESCC) remains controversial, as is the true prevalence of HPV infection in ESCC. The wide range in reported rates reflects variability in the primary literature, with some larger scale case-control studies suggesting the infection rates range from 0% to 78%. Interactions between HPV and the Barrett's metaplasia-dysplasia-carcinoma sequence have been explored, and these studies have shown some conflicting data. Overall, systematic reviews have reported the prevalence of HPV-positive DNA in esophageal adenocarcinoma patients of between 13% and 35%. Postulated reasons for discrepancies in HPV prevalence rates in esophageal cancer include variations in testing methodology and assay sensitivities; technical issues, including the lack of a gold-standard primer; types of specimens utilized (fresh-frozen versus formalin-fixed tissue); geographical variation; cross-contamination; and small sample sizes. Thus, efforts must be undertaken to (1) standardize HPV testing, ideally in a central laboratory and utilizing tests that detect viral transcriptional activity; (2) avoid cross-contamination; and (3) recruit large numbers of patients to accurately ascertain HPV rates in esophageal malignancy.

The role of viruses in adenocarcinoma development

Cancer is a leading public health issue that accounts for million deaths around the world every year. Human cancers contain over 100 types, which are categorized into different groups. Adenocarcinoma is one of those categories of cancer that begins from the glans and involves various tissues such as lung, esophagus, pancreas, prostate and colorectal. A range of risk factors has been identified for the development and progression of adenocarcinomas. One of these risk factors are viruses that serves special mechanisms to affect important host cell factors and tumorigenic pathways, contributing in development and promotion of adenocarcinomas. Here, we summarized the main viruses and their mechanisms implicated in the course of various adenocarcinomas development.

Importance of investigating high-risk human papillomavirus in lymph node metastasis of esophageal adenocarcinoma

High-risk human papillomavirus has been suggested as a risk factor for esophageal adenocarcinoma. Tumor human papillomavirus status has been reported to confer a favorable prognosis in esophageal adenocarcinoma. The size of the primary tumor and degree of lymphatic spread determines the prognosis of esophageal carcinomas. Lymph node status has been found to be a predictor of recurrent disease as well as 5-year survival in esophageal malignancies. In human papillomavirus driven cancers, e.g. cervical, anogenital, head and neck cancers, associated lymph nodes with a high viral load suggest metastatic lymph node involvement. Thus, human papillomavirus could potentially be useful as a marker of micro-metastases. To date, there have been no reported studies regarding human papillomavirus involvement in lymph nodes of metastatic esophageal adenocarcinoma. This review highlights the importance of investigating human papillomavirus in lymph node metastasis of esophageal adenocarcinoma based on data derived from other human papillomavirus driven cancers.

Antibodies against human papillomavirus proteins in Barrett's dysplasia and intramucosal esophageal adenocarcinoma

High-risk human papillomavirus (HPV) types 16/18 have been associated with Barrett's dysplasia (BD)/esophageal adenocarcinoma (EAC). Nevertheless, no data exist in relation to serological analysis for HPV antibodies in BD/EAC with site-specific viral DNA status. We prospectively examined antibodies to multiple HPV types in 438 patients representing hospital/reflux controls and Barrett's metaplasia (BM)/BD/intramucosal EAC. Antibody responses to HPV6/11/16/18/31/33/45/52/58 were analyzed using multiplex serology, including antibodies to E6/E7/E1/E2 and L1 antigens. Seropositivity for individual HPV proteins was infrequent in both cases and controls and was ≤10.2%. There was no difference in the seroprevalence of antibodies to any HPV antigen/antibody combination between reclassified cases (BD/EAC) and controls (hospital/reflux/BM) or between HPV16 or HPV18 DNA cases and controls, respectively. Among HPV16 DNA-positive BD/EAC cases, antibodies to HPV16 E7 were significantly more prevalent (3/26, 11.5%) than in hospital and reflux controls plus BM (5/328, 1.5%) (adjusted OR = 10.12, 95% CI: 1.61-63.73, P = 0.014). Among HPV18 DNA-positive cases, antibodies to HPV18 E1 were present in 3/6 (50%) cases versus 5/328 (1.5%) controls (adjusted OR = 44.28, 95% CI: 6.10-321.47, P = 0.0002). Although antibodies against HPV were generally uncommon in cases and controls, immune responses against two early proteins of HPV16/18 were significantly more frequent in viral DNA-positive BD/intramucosal EAC.

Association of Biomarkers for Human Papillomavirus With Survival Among Adults With Barrett High-grade Dysplasia and Esophageal Adenocarcinoma

IMPORTANCE

The presence of high-risk human papillomavirus (HPV) has been associated with a favorable outcome in Barrett high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). Nevertheless, the prognostic significance of other HPV-related biomarkers (ie, retinoblastoma protein [pRb], cyclin D1 [CD1], minichromosome maintenance protein [MCM2] and Ki-67) is unknown.

OBJECTIVE

To examine the association between HPV-related biomarkers and survival in adult patients with Barrett HGD and EAC.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective case-control study examined the hypothesis that the HPV-related cell cycle markers (pRb, CD1, and Ki-67) and the viral surrogate marker (MCM2) may be associated with a favorable prognosis in Barrett HGD and EAC. Pretreatment biopsies were used for HPV DNA determination via polymerase chain reaction and immunohistochemistry for the HPV-related biomarkers. Recruitment of patients occurred in secondary and tertiary referral centers, with 151 patients assessed for eligibility. The study period was from December 1, 2002, to November 28, 2017, and the dates of analysis were from September 9, 2011, to November 28, 2017.

MAIN OUTCOMES AND MEASURES

Disease-free survival and overall survival.

RESULTS

Of 151 patients assessed for eligibility, 9 were excluded. Among the 142 patients with Barrett HGD or EAC (126 [88.7%] men; mean [SD] age, 66.0 [12.1] years; 142 [100%] white), 37 were HPV positive and 105 were HPV negative. No association with disease-free survival was noted for pRb, CD1, Ki-67, and MCM2. In regard to overall survival, only low expression of CD1 had a favorable prognosis (hazard ratio [HR], 0.53; 95% CI, 0.30-0.95; adjusted P = .03). All the biomarkers stratified by HPV status showed significant associations with survival. Patients with HPV-positive, low-expression pRb esophageal tumors were associated with a significantly improved disease-free survival compared with the HPV-negative, high-expression Rb tumors (HR, 0.33; 95% CI, 0.12-0.93; adjusted P = .04). Similarly, HPV-positive, low-expression CD1 was associated with a significantly favorable disease-free survival (HR, 0.26; 95% CI, 0.09-0.76; adjusted P = .01), as was HPV-positive, high-expression MCM2 (HR, 0.27; 95% CI, 0.09-0.78; adjusted P = .02). In regard to overall survival, HPV was significantly associated only with low CD1 (HR, 0.38; 95% CI, 0.15-0.94; adjusted P = .04).

CONCLUSIONS AND RELEVANCE

This study's findings suggest that low expression of CD1 appears to be an independent prognostic marker in Barrett HGD and EAC. Human papillomavirus positivity in combination with pRb, CD1, MCM2, and Ki-67 was associated with a survival benefit in esophageal tumors. These findings suggest the possibility of personalization of therapy for Barrett HGD and EAC based on viral status.

Circulating human papillomavirus DNA detection in Barrett's dysplasia and esophageal adenocarcinoma

There is evidence to suggest that human papillomaviruses (HPV) are associated with Barrett's dysplasia and esophageal adenocarcinoma. In other HPV-linked cancers such as cervical and oropharyngeal cancer, circulating HPV DNA is a potential biomarker to assist in tumor diagnosis and management. This study aimed to determine whether circulating HPV DNA was detectable in patients with Barrett's dysplasia and esophageal adenocarcinoma, and if so, whether there is any correlation with esophageal tissue HPV status. Plasma from 138 patients representing esophageal adenocarcinoma (N = 41), Barrett's dysplasia (N = 48) and hospital controls (N = 49) were analyzed for the presence of circulating HPV DNA using droplet-digital PCR targeting the E7 gene of HPV types 16 and 18. Circulating HPV DNA was detected in 11/138 (8.0%) study subjects including 1/49 (2.0%) hospital controls, 4/48 (8.3%) Barrett's dysplasia patients, and 6/41 (14.6%) esophageal adenocarcinoma patients. Detection of circulating HPV DNA was higher in patients with HPV-positive esophageal tissue (6/35, 17.1%) compared to those with HPV-negative specimens (5/103; 4.9%) (OR = 4.06; 95% CI 1.15-14.25; P = 0.020). The highest rates of detection occurred in esophageal adenocarcinoma patients, particularly those with invasive tumors that had breached the esophageal submucosa, had regional lymph node involvement or metastatic disease. Circulating HPV DNA was detectable in a subset of Barrett's dysplasia and esophageal adenocarcinoma patients. Detection was associated with tissue HPV positivity and possibly disease severity.

Transforming human papillomavirus infection and the esophageal transformation zone: prime time for total excision/ablative therapy?

High-risk human papillomavirus (hr-HPV) infection is causal for almost all cervical malignancy (both squamous and adenocarcinoma), 90% of anal neoplasia, 70% of penile tumors, and 25% of head and neck cancers. The shared immunogenetics of cervical and esophageal malignancy suggests that HPV infection could well be a common denominator in the etiology of both cancers. In this regard, we have demonstrated that transcriptionally active hr-HPV (genotypes 16 and 18) is strongly associated with Barrett's dysplasia and esophageal adenocarcinoma. Increasing hr-HPV viral load and integration status has been linked with greater disease severity along the Barrett metaplasia-dysplasia-adenocarcinoma sequence as has been demonstrated in cervical intraepithelial neoplasia and cancer. HPV infections in both the cervix and esophagus are both focal, i.e., present in greater quantities at the squamocolumnar junction (SCJ). HPV affinity is to junctional tissue, as basal cells are particularly accessible at the squamocolumnar transformation zone and especially susceptible to this viral infection. We have postulated that progressive acid damage to the esophagus increases the likelihood of mucosal breaks enabling the virus to enter the basal layer of the transformation zone. The SCJ is the transformation zone of the esophagus and is strikingly similar to the transition zone (ectoendocervical SCJ) of the uterine cervix where almost all high-grade cervical lesions and cancers arise including 80% of adenocarcinomas. These transition zone cells exhibit features of squamous epithelium as well as glandular cells, which have been described in both Barrett's esophagus and cervical mucosa. Barrett's esophagus (BE) is derived from a discrete population of embryonic cells residing at the SCJ. There is loss of SCJ immune-phenotype following excision without regeneration at other junctional sites. Prevention of cervical cancer in up to 80-95% of patients with screen-detected CIN is dependent on the excision/ablation of the entire transformation zone. The persistence of hr-HPV 16/18 following eradication of CIN is a significant risk factor for recurrence. Similarly, we have demonstrated that persistent hr-HPV infection 16/18 and p53 overexpression are associated with treatment failure after endoscopic ablation of BD/EAC. Thus, we believe that excision/ablation of the SCJ in patients with BD/intramucosal EAC should be performed to reduce the potential malignant risk. We propose to test this hypothesis by a multicenter randomized controlled trial whereby patients (both HPV positive and those which are virus negative) will be allocated into two arms: complete excision of the SCJ via endoscopic mucosal resection (EMR) in addition to radiofrequency ablation (RFA) ± EMR of BD/intramucosal EAC (experimental arm) versus current standard of care (RFA ± EMR) of said lesions. Treatment efficacy in both groups will be evaluated by comparing disease elimination, regression/progression, and recurrence (if any). All patients would be entered into an intensive endoscopic surveillance protocol (biannually) for at least 2 years with lesional/neosquamous biopsies to compare the recurrence rate of both dysplasia/neoplasia in both arms. Viral (HPV DNA/p16INK4A/E6/E7 mRNA) and host biomarkers (e.g., p53) will be analyzed both at baseline and posttreatment intervals. A positive study would initiate development of tools best suited for SCJ destruction.

Survival Rates for Patients With Barrett High-grade Dysplasia and Esophageal Adenocarcinoma With or Without Human Papillomavirus Infection

IMPORTANCE

High-risk human papillomavirus (HPV) has been associated with Barrett dysplasia and esophageal adenocarcinoma. Nevertheless, the prognostic significance of esophageal tumor HPV status is unknown.

OBJECTIVE

To determine the association between HPV infection and related biomarkers in high-grade dysplasia or esophageal adenocarcinoma and survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective case-control study. The hypothesis was that HPV-associated esophageal tumors would show a favorable prognosis (as in viral-positive head and neck cancers). Pretreatment biopsies were used for HPV DNA determination via polymerase chain reaction, in situ hybridization for E6 and E7 messenger RNA (mRNA), and immunohistochemistry for the proteins p16INK4A and p53. Sequencing of TP53 was also undertaken. The study took place at secondary and tertiary referral centers, with 151 patients assessed for eligibility and 9 excluded. The study period was from December 1, 2002, to November 28, 2017.

MAIN OUTCOMES AND MEASURES

Disease-free survival (DFS) and overall survival (OS).

RESULTS

Among 142 patients with high-grade dysplasia or esophageal adenocarcinoma (126 [88.7%] male; mean [SD] age, 66.0 [12.1] years; 142 [100%] white), 37 were HPV positive and 105 were HPV negative. Patients who were HPV positive mostly had high p16INK4A expression, low p53 expression, and wild-type TP53. There were more Tis, T1, and T2 tumors in HPV-positive patients compared with HPV-negative patients (75.7% vs 54.3%; difference, 21.4%; 95% CI, 4.6%-38.2%; P = .02). Mean DFS was superior in the HPV-positive group (40.3 vs 24.1 months; difference, 16.2 months; 95% CI, 5.7-26.8; P = .003) as was OS (43.7 vs 29.8 months; difference, 13.9 months; 95% CI, 3.6-24.3; P = .009). Recurrence or progression was reduced in the HPV-positive cohort (24.3% vs 58.1%; difference, -33.8%; 95% CI, -50.5% to -17.0%; P < .001) as was distant metastasis (8.1% vs 27.6%; difference, -19.5%; 95% CI, -31.8% to -7.2%; P = .02) and death from esophageal adenocarcinoma (13.5% vs 36.2%; difference, -22.7%; 95% CI, -37.0% to -8.3%; P = .01). Positive results for HPV and transcriptionally active virus were both associated with a superior DFS (hazard ratio [HR], 0.33; 95% CI, 0.16-0.67; P = .002 and HR, 0.44; 95% CI, 0.22-0.88; P = .02, respectively [log-rank test]). Positivity for E6 and E7 mRNA, high p16INK4A expression, and low p53 expression were not associated with improved DFS. On multivariate analysis, superior DFS was demonstrated for HPV (HR, 0.39; 95% CI, 0.18-0.85; P = .02), biologically active virus (HR, 0.36; 95% CI, 0.15-0.86; P = .02), E6 and E7 mRNA (HR, 0.36; 95% CI, 0.14-0.96; P = .04), and high p16 expression (HR, 0.49; 95% CI, 0.27-0.89; P = .02).

CONCLUSIONS AND RELEVANCE

Barrett high-grade dysplasia and esophageal adenocarcinoma in patients who are positive for HPV are distinct biological entities with a favorable prognosis compared with viral-negative esophageal tumors. Confirmation of these findings in larger cohorts with more advanced disease could present an opportunity for treatment de-escalation in the hope of reducing toxic effects without deleteriously affecting survival.

Human papillomavirus does not play a role in the Barrett esophagus: a French cohort

The role of human papillomavirus (HPV) in Barrett's esophagus (BE) has been examined but remains unclear. The purpose of the study is to dispute the connection between HPV and BE in a prospective case-control study. Biopsies were performed above and inside the Barrett's segment for BE patients and in the distal third of the esophagus for control patients for histological interpretation and for virological analysis. Biopsies for virological analysis were placed in a virus transport medium and immediately frozen in liquid nitrogen. Virological analysis involved real-time PCR using the SyBr® green protocol with modified SPF10 general primers. A total of 180 patients (119 control and 61 BE, respectively) were included. In BE patients, 31, 18, and 12 patients had, respectively, no dysplasia, low-grade dysplasia, and high grade dysplasia. Overall, nine were found to be HPV positive: five were control patients and four BE patients. HPV positive status was not associated with BE. No factors were associated with HPV, in particular the degree of BE dysplasia. HPV infection appears unlikely to be significant in the etiology of BE compared with control patients. (ClinicalTrials.gov, Number NCT02549053).

Active human papillomavirus involvement in Barrett's dysplasia and oesophageal adenocarcinoma is characterized by wild-type p53 and aberrations of the retinoblastoma protein pathway

We have previously demonstrated that transcriptionally active high-risk HPV (hr-HPV) is strongly incriminated in Barrett's dysplasia (BD) and oesophageal adenocarcinoma (OAC) using mainly fresh frozen tissue. This study aimed to identify biomarkers of active HPV infection in Barrett's metaplasia, (BM)/BD/OAC by immunohistochemical staining (IHC) of formalin-fixed paraffin embedded (FFPE) tissue for aberrations of p53 and the retinoblastoma (pRb) pathway, which are targets for the viral oncoproteins, E6/E7, respectively. Prospectively, BM (n = 81)/BD (n = 72)/OAC (n = 65) FFPE specimens were subjected to IHC staining for pRb, p16^INK4A , cyclin D₁ , p53 and RNA in-situ hybridization for E6/E7 transcripts. HPV DNA was determined via PCR in fresh frozen specimens. Viral load measurement (real-time PCR) and Next Generation Sequencing of TP53 was performed. Of 218 patients, 56 were HPV DNA positive [HPV16 (n = 42), 18 (n = 13), 6 (n = 1)]. Viral load was low. Transcriptionally active HPV (DNA⁺ /RNA⁺ ) was only found in the dysplastic and adenocarcinoma group (n = 21). The majority of HPV DNA⁺ /RNA⁺ BD/OAC were characterized by p 16highINK4A (14/21, 66.7%), pRb_low (15/21, 71.4%) and p53_low (20/21, 95%) and was significantly different to controls [combination of HPV DNA^- /RNA^- (n = 94) and HPV DNA⁺ /RNA^- cohorts (n = 22)]. p53_low had the strongest association with DNA⁺ /RNA⁺ oesophageal lesions (OR = 23.5, 95% CI = 2.94-187.8, p = 0.0029). Seventeen HPV DNA⁺ /RNA⁺ BD/OAC identified as p53_low, were sequenced and all but one exhibited wild-type status. pRb_low /p53_low provided the best balance of strength of association (OR = 8.0, 95% CI = 2.6-25.0, p = 0.0003) and sensitivity (71.4%)/specificity (71.6%) for DNA⁺ /RNA⁺ BD/OAC. Active HPV involvement in BD/OAC is characterized by wild-type p53 and aberrations of the retinoblastoma protein pathway.

The prevalence of viral agents in esophageal adenocarcinoma and Barrett's esophagus: a systematic review

BACKGROUND AND AIMS

Human papilloma virus (HPV), which may reach the esophagus through orogenital transmission, has been postulated to be associated with esophageal adenocarcinoma (EAC). A systematic review of the literature investigating the prevalence of infectious agents in EAC and Barrett's esophagus (BE) was carried out.

METHODS

Using terms for viruses and EAC, the Medline, Embase, and Web of Science databases were systematically searched for studies published, in any language, until June 2016 that assessed the prevalence of viral agents in EAC or BE. Random-effects meta-analyses of proportions were carried out to calculate the pooled prevalence and 95% confidence intervals (CIs) of infections in EAC and BE.

RESULTS

A total of 30 studies were included. The pooled prevalence of HPV in EAC tumor samples was 13% (n=19 studies, 95% CI: 2-29%) and 26% (n=6 studies, 95% CI: 3-59%) in BE samples. HPV prevalence was higher in EAC tissue than in esophageal tissue from healthy controls (n=5 studies, pooled odds ratio=3.31, 95% CI: 1.15-9.50). The prevalence of Epstein-Barr virus (EBV) in EAC was 6% (n=5, 95% CI: 0-27%). Few studies have assessed other infectious agents. For each of the analyses, considerable between-study variation was observed (I=84-96%); however, sensitivity analyses did not show any major sources of heterogeneity.

CONCLUSION

The prevalence of HPV and EBV in EAC is low compared with other viral-associated cancers, but may have been hampered by small sample sizes and detection methods susceptible to fixation processes. Additional research with adequate sample sizes and high-quality detection methods is required.

Human papillomavirus not detected in esophageal adenocarcinoma tumor specimens

BACKGROUND

Human papillomavirus (HPV) has been implicated as playing a causal role in Barrett's esophagus, the metaplastic precursor to esophageal adenocarcinomas (EAC) and gastro-esophageal junction adenocarcinomas (GEJACs). We evaluated the presence of HPV DNA in EACs and GEJACs.

STUDY DESIGN

We analyzed 241 histologically confirmed archived EAC and GEJAC tissue specimens from a population-based study in Australia. Samples were tested by PCR for DNA quality (β-globin) and for the presence of HPV DNA.

RESULTS

DNA yield and quality was satisfactory in 97% (233/241; 201 EAC, 32 GEJAC). Each sample was tested three times for HPV DNA, but none of the 233 tumor specimens tested positive.

CONCLUSIONS

We found no evidence of HPV DNA in esophageal adenocarcinoma tumor cells. HPV is unlikely to cause EAC or GEJAC.

Detection of human papillomavirus in esophageal and gastroesophageal junction tumors: A retrospective study by real-time polymerase chain reaction in an instutional experience from Turkey and review of literature

Esophageal cancer is a poor-prognosis malignancy that ranks eighth among all cancer types, and its prevalence shows differences among geographical regions. Although the most important risk factors for esophageal carcinoma are alcohol and smoking, viral infections, particularly HPV infection, are also considered among etiological agents. Our study aims to detect the presence of HPV in esophageal cancers in our patient population and to investigate its correlation with clinico-pathological parameters. We investigated the presence of HPV-DNA by real-time polymerase chain reaction in a total of 52 patients with esophageal cancer. Subtype analysis was performed in positive cases and was correlated with selected clinico-pathological parameters. Five (9.6%) of 52 tumor samples, 3 squamous cell carcinomas (3/33 cases) and 2 adenocarcinomas (2/19 cases), were HPV-DNA-positive. Subtype analysis could be performed in four HPV-DNA-positive cases, of which three were HPV type-39 and 1 was type-16. The Marmara region, where the present study was carried out, is a region with low-moderate risk for esophageal cancer, and the prevalence of HPV-DNA in these tumors is similar to the prevalence of HPV-DNA reported in the literature for regions with similar risk. In conclusion, we detected HPV DNA in a subset of esophageal and gastroesophageal junction tumors. HPV infection may have a role in esophageal carcinogenesis and high-risk HPV subtypes can particularly be considered among risk factors since the prevalence of high risk HPV infection has also been found to be increased in regions with a high risk for esophageal cancer compared to low-moderate risk regions.

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.

Microbiome, innate immunity, and esophageal adenocarcinoma

With the development of culture-independent technique, a complex microbiome has been established and described in the distal esophagus. The incidence of esophageal adenocarcinoma (EAC) has increased dramatically in the United States. Studies documenting an altered microbiome associated with EAC and its precedents suggest that dysbiosis may be contributing to carcinogenesis, potentially mediated by interactions with toll-like receptors. Investigations attempting to associate viruses with EAC have not been as consistent. Currently available data are cross-sectional and therefore cannot prove causal relationships. Prospectively, microbiome studies open a new avenue to the understanding of the etiology and pathogenesis of reflux disorders and EAC.

Human papillomavirus was not detected by PCR using multiple consensus primer sets in esophageal adenocarcinomas in Chinese patients

The role of human papillomavirus (HPV) infection in the development of esophageal squamous cell carcinoma is well established; however, there are few reports on the role of HPV in esophageal adenocarcinoma. To evaluate the putative role of HPV infection in esophageal adenocarcinoma, 57 formalin-fixed, paraffin-embedded esophageal adenocarcinoma specimens were collected from four hospitals in Shanghai and Anyang, China, between 1999 and 2008. HPV DNA was analyzed using PCR with multiple sets of consensus primers for HPV, GP5+/6+, CPI/CPIIG, SPF10, pU-1M/pU2R, and pU31B/pU2R. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the internal control, was amplified successfully in all 57 specimens. However, HPV amplification was not detected in any specimens with any of the consensus primer sets used. The present study indicates that HPV infection is not likely to be a major factor in the etiology of esophageal adenocarcinoma in the Chinese population.

Transcriptionally active human papillomavirus is strongly associated with Barrett's dysplasia and esophageal adenocarcinoma

OBJECTIVES

The role of human papillomavirus (HPV) in Barrett's esophagus (BE) remains unclear. The few studies that have previously investigated HPV and esophageal adenocarcinoma (EAC) or BE have produced either negative data or positive results of doubtful clinical/etiological significance or have detected only low-risk HPV types. We therefore prospectively determined the prevalence of biologically active HPV in esophageal epithelium of patients representing the Barrett's metaplasia-dysplasia-adenocarcinoma sequence.

METHODS

HPV DNA was estimated by nested PCR and viral transcriptional activity detected by E6/7 oncogene mRNA expression and p16INK4A immunohistochemistry in fresh frozen and paraffin-embedded esophageal biopsies of patients with BE, Barrett's dysplasia (BD), and EAC, as well as controls. Biopsies were obtained from the transformation zone (squamocolumnar junction (SCJ)) and the lesion, or corresponding site in controls, i.e., 2 cm above the gastroesophageal junction (GEJ).

RESULTS

Of the 261 patients, 81 were positive for HPV DNA. In controls and BE, the virus was mostly detected at the transformation zone. Compared with controls (18.0%), HPV positivity was significantly more common in BD (68.6%, incidence rate ratio (IRR) 2.94, 95% confidence interval (CI) 1.78-4.85, P<0.001) and EAC (66.7%, IRR 2.87, 95% CI 1.69-4.86, P<0.001), but not in BE (22.1%, IRR 1.06, 95% CI 0.60-1.85, P=0.85). Of the patients, 92.6% were high-risk (HR) HPV, i.e., types 16 and 18. Again, p16INK4A positivity was greatest in BD and EAC and much less in BE patients (44.1%, IRR 17.0 (95% CI 4.86-59.6, P<0.001), 44.4%, 17.0 (95% CI 4.87-59.4, P<0.001), and 10.6%, 3.93 (95% CI 1.01-15.3, P=0.048) respectively). In 66 HPV DNA-positive patients tested for E6/E7 mRNA, none of the control (n=16) or BE (n=13) individuals were positive, whereas 9/22 BD and 9/15 EAC patients demonstrated oncogene expression (P<0.001). When HPV DNA, p16INK4A, and E6/E7 mRNA were all positive, there was a very strong association with disease severity (SCJ: odds ratio (OR) 104, 95% CI 20.3-529, P<0.001; lesion: OR 62.2, 95% CI 12.4-311, P<0.001) than when all were negative.

CONCLUSIONS

Transcriptionally active HR-HPV was strongly associated with BD and EAC, but was largely biologically irrelevant in BE and controls, suggesting a potential role in esophageal carcinogenesis. These data provide robust justification for further detailed longitudinal, interventional, and molecular studies.

Human papillomavirus and the risk of Barrett's esophagus

Human papillomavirus (HPV) is strongly associated with squamous esophageal cancer. The potential role of HPV in Barrett's esophagus (BE) has been examined but remains unclear. The aim of the study was to determine the prevalence of HPV in esophageal and gastric tissues obtained from patients with and without BE. We designed a cross-sectional study was conducted with prospective enrollment of eligible patients scheduled for esophagogastroduodenoscopy (EGD). All participants had biopsies of endoscopic BE, squamous-lined esophagus, and stomach. Immunohistochemistry (IHC) on formalin-fixed and paraffin-embedded tissue was conducted using monoclonal antibodies. Polymerase chain reaction (PCR) for HPV was performed on DNA extracted from esophageal biopsies snapped frozen within 30 minutes after endoscopic capture. The Roche HPV Linear Array Assay with PGMY primers that has high sensitivity for detecting 37 types of HPV was used. A total of 127 subjects were included: 39 with definitive BE had IHC done on samples from non-dysplastic BE, squamous esophagus, gastric cardia, and gastric body; and 88 control patients without BE had IHC done on squamous esophageal samples, gastric cardia, and gastric body. HPV was not detected in any of the samples in either group. For confirmation, HPV DNA PCR was performed on randomly selected samples from 66 patients (both esophagus and BE from 13 patients with BE, and 53 esophagus from patients without BE); no sample had HPV DNA detected via PCR in the presence of adequate quality control. HPV infection does not play a role in the formation of non-dysplastic Barrett's esophagus in men in the United States.

Vaccination against human papilloma virus (HPV): epidemiological evidence of HPV in non-genital cancers

Recently, the vaccine against human papillomavirus (HPV) was introduced in the national vaccination programmes of several countries worldwide. The established association between HPV and the progression of cervical neoplasia provides evidence of the expected protection of the vaccine against cervical cancer. During the last two decades several studies have also examined the possible involvement of HPV in non-genital cancers and have proposed the presence of HPV in oesophageal, laryngeal, oropharyngeal, lung, urothelial, breast and colon cancers. The possible involvement of HPV in these types of cancer would necessitate the introduction of the vaccine in both boys and girls. However, the role of HPV in the pathogenesis of these types of cancer has yet to be proven. Moreover, the controversial evidence of the possible impact of the vaccination against HPV in the prevention of non-genital cancers needs to be further evaluated. In this review, we present an overview of the existing epidemiological evidence regarding the detection of HPV in non-genital cancers.

Esophageal verrucous carcinoma arising from hyperkeratotic plaques associated with human papilloma virus type 51

Esophageal verrucous carcinoma is a rare variant of esophageal squamous cell carcinoma. We report a case of esophageal verrucous carcinoma associated with human papilloma virus (HPV) type 51. The patient had long-standing dysphagia and odynophagia, and white esophageal plaques showing hyperkeratosis on biopsy. At repeat endoscopy, the esophagus was covered with verrucous white plaques and areas of nodular mucosa with white fronds, with a distal 10-cm smooth mass protruding into the lumen. Biopsies demonstrated an atypical squamoproliferative lesion but no frank malignancy. HPV type 51 DNA was detected in endoscopic biopsy specimens by polymerase chain reaction. Because the size of the lesion favored an underlying verrucous carcinoma, our patient underwent minimally invasive esophagectomy with gastric pull-up and cervical anastomosis. The pathologic diagnosis was a well-differentiated esophageal verrucous carcinoma. One year after esophagectomy, the patient feels well and is free of disease. Although HPV DNA was not detected in the cancer tissue obtained at surgery, our case suggests an association between HPV type 51 and esophageal verrucous carcinoma. The clinical evolution in this case highlights the importance of endoscopic surveillance in patients with exuberant esophageal hyperkeratosis, and of definitive surgical resection when malignancy is suspected even if frank malignancy is not demonstrated on superficial biopsies.