Persistence of Human Papillomavirus, Overexpression of p53, and Outcomes of Patients After Endoscopic Ablation of Barrett's Esophagus

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.

Study to investigate the prevalence of human papillomavirus in Barrett's oesophagus using a novel screening methodology

Introduction

Human papillomavirus (HPV) is strongly associated with Barrett’s dysplasia and oesophageal cancer suggesting a role in carcinogenesis. HPV persistence predicts treatment failure after endotherapy for Barrett’s dysplasia. This pilot study applies a novel HPV screening tool (previously only used in the oropharynx) to detect HPV DNA directly and determine the prevalence rates in Barrett’s oesophagus (BO).

Method

DNA was extracted from 20 formalin-fixed BO samples. HPV DNA was detected using real-time PCR and gel electrophoresis.

Results

5 out of 20 patients were identified as positive for HPV. Prevalence was 25% in patients with BO.

Conclusion

This method can be used in BO’s tissue to determine HPV infection. Adoption of this as a screening test could potentially revolutionise future research in this area. If a clear link between HPV and Barrett’s dysplasia can be confirmed, this qPCR method has the potential to aid in monitoring and/or dysplasia detection by stratifying those most at risk and aid in the development of new therapies.

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.

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.

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.

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.

Barrett Esophagus and Intramucosal Esophageal Adenocarcinoma

Barrett esophagus (BE) is a precursor lesion for esophageal adenocarcinoma (EAC). Developments in imaging and molecular markers, and endoscopic eradication therapy, are available to curb the increase of EAC. Endoscopic surveillance is recommended, despite lack of data. The cancer risk gets progressively downgraded, raising questions about the understanding of risk factors and molecular biology involved. Recent data point to at least 2 carcinogenic pathways operating in EAC. The use of p53 overexpression and high-risk human papillomavirus may represent the best chance to detect progressors. Genome-wide technology may provide molecular signatures to aid diagnosis and risk stratification in BE.

Human papillomavirus and gastrointestinal cancer: A review

Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. Exposure to HPV is very common, and an estimated 65%-100% of sexually active adults are exposed to HPV in their lifetime. The majority of HPV infections are asymptomatic, but there is a 10% chance that individuals will develop a persistent infection and have an increased risk of developing a carcinoma. The International Agency for Research on Cancer has found that the following cancer sites have a strong causal relationship with HPV: cervix uteri, penis, vulva, vagina, anus and oropharynx, including the base of the tongue and the tonsils. However, studies of the aetiological role of HPV in colorectal and esophageal malignancies have conflicting results. The aim of this review was to organize recent evidence and issues about the association between HPV infection and gastrointestinal tumours with a focus on esophageal, colorectal and anal cancers. The ultimate goal was to highlight possible implications for prognosis and prevention.

Genomic analysis of HPV-positive versus HPV-negative oesophageal adenocarcinoma identifies a differential mutational landscape

BACKGROUND

High-risk human papillomavirus (hr-HPV) has been implicated in a subset of patients with oesophageal adenocarcinoma (OAC). We therefore hypothesised that HPV associated OAC may have distinct genomic aberrations compared with viral negative oesophageal cancer.

METHODS

Whole exome sequencing was performed to explore the mutational landscape and potential molecular signature of HPV-positive versus HPV-negative OAC. Four hr-HPV-positive and 8 HPV-negative treatment-naive fresh-frozen OAC tissue specimens and matched normal tissue were analysed to identify somatic genomic mutations. Data were subjected to cancer driver gene identification and pathway analysis.

RESULTS

The HPV-positive cohort harboured approximately 50% less non-silent somatic mutations than the virus-negative patients with oesophageal cancer (1.31 mutations/Mb vs 2.56 mutations/Mb, p=0.048). TP53 aberrations were absent in the HPV-positive OAC group whereas 50% of the HPV-negative patients with OAC exhibited TP53 mutations. HPV-negative cancers were enriched with non-silent mutations in cancer driver genes, but not HPV-positive tumours. Enriched A>C transversions at adenine-adenine (AA) dinucleotide was observed in 5/7 Siewert class I OAC samples but none (0/5) in Siewert class II tumours (p=0.027).

CONCLUSIONS

These findings demonstrate distinct genomic differences between HPV-positive and HPV-negative OACs indicating different biological mechanisms of tumour formation.

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.