Barrett's oesophagus and adenocarcinoma

Proposal for an Organ-Specific Chronic Inflammation–Remodeling–Carcinoma Sequence

An organ-specific chronic inflammation–remodeling–carcinoma sequence has been proposed, mainly for the alimentary tract. As representative diseases, gastroesophageal reflux disease, chronic gastritis and inflammatory bowel disease (ulcerative colitis and Crohn’s disease of the colitis type) were adopted for this discussion. Tissue remodeling is such an important part of tumorigenesis in this sequence that an organ-specific chronic inflammation–remodeling–carcinoma sequence has been proposed in detail. Chronic inflammation accelerates the cycle of tissue injury and regeneration; in other words, cell necrosis (or apoptosis) and proliferation result in tissue remodeling in long-standing cases of inflammation. Remodeling encompasses epithelial cell metaplasia and stromal fibrosis, and modifies epithelial–stromal cell interactions. Further, the accumulation of genetic, epigenetic and molecular changes—as well as morphologic disorganization—also occurs during tissue remodeling. The expression of mucosal tissue adapted to chronic inflammatory injury is thought to occur at an early stage. Subsequently, dysplasia and carcinoma develop on a background of remodeling due to continuous, active inflammation. Accordingly, organ-specific chronic inflammation should be ameliorated or well controlled with appropriate monitoring if complete healing is unachievable.

Barrett’s esophagus in 2016: From pathophysiology to treatment

Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett’s esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE.

EAES recommendations for the management of gastroesophageal reflux disease

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most frequent benign disorders of the upper gastrointestinal tract. Management of GERD has always been controversial since modern medical therapy is very effective, but laparoscopic fundoplication is one of the few procedures that were quickly adapted to the minimal access technique. The purpose of this project was to analyze the current knowledge on GERD in regard to its pathophysiology, diagnostic assessment, medical therapy, and surgical therapy, and special circumstances such as GERD in children, Barrett's esophagus, and enteroesophageal and duodenogastroesophageal reflux.

METHODS

The European Association of Endoscopic Surgery (EAES) has tasked a group of experts, based on their clinical and scientific expertise in the field of GERD, to establish current guidelines in a consensus development conference. The expert panel was constituted in May 2012 and met in September 2012 and January 2013, followed by a Delphi process. Critical appraisal of the literature was accomplished. All articles were reviewed and classified according to the hierarchy of level of evidence and summarized in statements and recommendations, which were presented to the scientific community during the EAES yearly conference in a plenary session in Vienna 2013. A second Delphi process followed discussion in the plenary session.

RESULTS

Recommendations for pathophysiologic and epidemiologic considerations, symptom evaluation, diagnostic workup, medical therapy, and surgical therapy are presented. Diagnostic evaluation and adequate selection of patients are the most important features for success of the current management of GERD. Laparoscopic fundoplication is the most important therapeutic technique for the success of surgical therapy of GERD.

CONCLUSIONS

Since the background of GERD is multifactorial, the management of this disease requires a complex approach in diagnostic workup as well as for medical and surgical treatment. Laparoscopic fundoplication in well-selected patients is a successful therapeutic option.

Carcinogenesis of Barrett's esophagus: a review of the clinical literature

Barrett's esophagus (BE) is a premalignant condition of esophageal adenocarcinoma (EAC). Although the incidence of BE has risen rapidly in the West, it is rare in Asia despite a recent increase in the prevalence of gastroesophageal reflux disease. Controversies over the definition of BE are presented because most cases show short-segment BE, especially ultra-short BE, in Asia. Here we review possible risk factors for the development of EAC, particularly possible roles of ethnicity, specialized intestinal metaplasia (SIM), BE length, and environmental factors, such as Helicobacter pylori infection and obesity. Additionally, we summarize recent studies on the effect of chemoprevention including proton pump inhibitors, nonsteroidal anti-inflammatory drugs or aspirin in order to reduce the risk of neoplastic progression in BE patients. Although substantial knowledge of risk factors of dysplasia/EAC in BE is shown, the risk for neoplastic development may be influenced by geographic variation, study population, the presence or absence of SIM or dysplasia at baseline, and the small number of BE patients investigated. Recently, the efficiency of surveillance for BE patients has been discussed from the standpoint of cost-effectiveness. It may be too difficult to draw conclusions because no randomized clinical trials of BE surveillance have been performed.

Cryoablation of persistent Barrett's epithelium after definitive chemoradiation therapy for esophageal adenocarcinoma

BACKGROUND

Dysplastic Barrett's epithelium (BE) persists after chemoradiation therapy for esophageal adenocarcinoma (EAC) arising in Barrett's esophagus. This phenomenon may present a significant risk for development of metachronous adenocarcinoma.

OBJECTIVE

To analyze the safety and efficacy of endoscopic cryoablation therapy for persistent dysplastic BE in patients with complete clinical response after definitive chemoradiation therapy for EAC.

DESIGN

Retrospective cohort study.

SETTING

Single National Cancer Institute Comprehensive Cancer Center experience.

PATIENTS

Radiation and endoscopic oncology treatment records were reviewed between January 2004 and September 2009. Fourteen patients with EAC who had been treated with definitive chemoradiation therapy followed by cryoablation were identified.

INTERVENTION

Cryoablation therapy.

MAIN OUTCOME MEASUREMENTS

Reduction in Prague Classification and dysplasia status following cryoablation therapy. Complications reported at 24 hour after the procedure telephone survey and at subsequent endoscopy.

RESULTS

After complete clinical response of EAC to chemoradiation therapy, the median length of persistent BE was Prague classification C1M4 (C = circumferential extent, M = maximal extent). Cryoablation reduced the median length of persistent BE to Prague classification C0M1 (P = .009 with respect to circumferential extent and P = .004 with respect to maximal extent of BE). All 14 patients had dysplastic BE. Cryoablation resulted in histological downgrading in all 14 patients. Among patients with high-grade dysplasia, 20% (2/10) were reduced to low-grade dysplasia, 60% (6/10) to BE with no dysplasia, and 20% (2/10) to no BE. Among patients with low-grade dysplasia, 75% (3/4) were reduced to BE with no dysplasia, and 25% (1/4) to no BE. The median number of cryoablation treatments administered to the 14 patients evaluated was 1 (mean 1.5, range 1-5). Eighty-six percent (12/14) of patients reported no complaints during the 24 hours after cryoablation. No occurrences of perforation and no esophageal strictures were reported at surveillance endoscopy.

LIMITATIONS

Single-center, retrospective design involving a small number of patients.

CONCLUSION

Our observations suggest that cryoablation therapy is safe and effective for the treatment of persistent BE after definitive chemoradiation.

Obesity, metabolic syndrome and esophageal adenocarcinoma: epidemiology, etiology and new targets

BACKGROUND

Rates of distal and junctional adenocarcinomas are increasing in Western countries.

METHODS

Systematic review of epidemiological evidence linking obesity to esophageal adenocarcinoma (EA) was performed for studies published from 2005 to 2010. The current understanding of obesity's role in the etiology and potential dysplastic progression of Barrett's esophagus (BE) to EA is reviewed.

RESULTS

Accumulating epidemiological studies provide evidence of obesity's role as a driving force behind the increasing rates of EA. The simplest construct is that obesity promotes reflux, causing chronic inflammation and BE, predisposing to adenocarcinoma. However, as obesity is positively associated with the prevalence of many cancers, other mechanisms are important. A link may exist between fat distribution patterns and the risk of BE and EA. Altered metabolic profiles in the metabolic syndrome (MetS) may be a key factor in cell cycle/genetic abnormalities that mark the progression of BE towards cancer. Research highlighting a unique role of MetS in the length of BE, and its association with systemic inflammation and insulin resistance is discussed, as well as adipokine receptor expression in both BE and esophageal epithelium, and how MetS and the systemic response impacts on key regulators of inflammation and tumorigenesis. CONCLUSIONS/IMPACT: Obesity is positively associated with EA. The systemic inflammatory state consequent on the altered metabolism of obese patients, and the associated impact of adipocytokines and pro-coagulant factors released by adipocytes in central fat, may underlie obesity's relationship to this cancer. Novel therapeutic agents that may antagonize adipo-cytokines and potentially offer a promising role in cancer therapy are discussed.

Pilot translational study of dietary vitamin C supplementation in Barrett's esophagus

The transcription factor Nuclear factor kappa B (NF-kappaB) is central to the regulation of genes encoding for mediators of inflammation and carcinogenesis. In the esophagus, NF-kappaB is progressively activated from inflammation to Barrett's metaplasia and adenocarcinoma. Vitamin C, an antioxidant, can inhibit NF-kappaB in in vitro models, and the aim of this study was to prospectively assess the effect of supplemental vitamin C on NF-kappaB and associated cytokines in patients with Barrett's esophagus. Twenty-five patients with long-segment Barrett's and specialized intestinal metaplasia received dietary vitamin C (1000 mg/day) orally for four weeks, and had pre- and post-vitamin C endoscopic biopsies. NF-kappaB activity (activated p50 and p65 subunits) of nuclear extracts was assessed using the Active Motif NF-kappaB assay, and cytokines and growth factors were measured using the Evidence Investigator biochip array. NF-kappaB and related pro-inflammatory cytokines and growth factors (IL-8, VEGF, IL-10) were activated in all Barrett's tissue pre-treatment. Down-regulation in activated NF-kappaB and cytokines was observed in 8/25 (35%) patients. Dietary vitamin C supplementation may down-regulate pro-inflammatory markers in a subset of Barrett's patients. Further studies with larger numbers of endpoints will be needed to further evaluate this effect.

The association between body mass index and Barrett's esophagus: a systematic review

Biological plausibility and evidence from case series indicate that an increased body mass index could be a risk factor for Barrett's esophagus. The aim of this study was to assemble and appraise the available evidence on the association of body mass index and Barrett's esophagus in a narrative approach. A systematic literature review identified a nested case-control study and 10 case-control studies, with sample sizes of between 129 and 953. Overall, cases were on average older than controls, more often male and white, but did not differ with regards to body mass index. An increased body mass index (> or =30 and > or =35 kg/m(2)) was associated with greater risk of Barrett's esophagus in four studies (odds ratio range: 2.0-4.0). These studies, however, did not adjust for symptoms suggestive of gastroesophageal reflux disease. No significant association was reported in the other six studies. To conclude, the existing evidence on the association between body mass index and risk of Barrett's esophagus relates primarily to case-control studies and is inconsistent. Gastroesophageal reflux symptoms can be a potential confounder and further research should better address this issue. Evidence from cohort studies may help shed further light on this putative association, which is of relevance to public health and cancer control.

Impact of gastro-esophageal reflux on mucin mRNA expression in the esophageal mucosa

INTRODUCTION

Changes in the expression of mucin genes in the esophageal mucosa associated with uncomplicated gastro-esophageal reflux disease have not been evaluated even though such changes could be associated with reflux-induced mucosal damage. We therefore sought to identify reflux-induced changes in mucin gene expression using a cell line and biopsies from the esophageal mucosa in patients with and without reflux.

METHODS

MUC-1, MUC-3, MUC-4, and MUC-5AC gene expressions were investigated in the HET-1A cell line following exposure to acid (pH 4) and/or bile (120 muM of a bile salt milieu), and in esophageal mucosal biopsies from controls, subjects with non-erosive gastro-esophageal reflux, and subjects with reflux associated with ulcerative esophagitis (erosive). The mucosal biopsies were also evaluated for IL-6 mRNA expression (inflammatory marker) and CK-14 mRNA expression (mucosal basal cell layer marker). Gene expression was determined using real-time reverse transcriptase-polymerase chain reaction analysis.

RESULTS

In the cell line studies, there were differences in mRNA levels for all of the evaluated mucins following treatment with either acid or the acid and bile combination. In the studies which evaluated tissue specimens, IL-6 and CK-14 mRNA levels increased according to degree of reflux pathology. The expression of MUC-1 and MUC-4 in mucosa from patients with erosive reflux was lower than in subjects without reflux and in patients with non-erosive reflux, whereas the expression of MUC-3 and MUC-5AC was increased (although these differences did not reach significance at p < 0.05). When mRNA expression data for tissue samples from all groups were combined, significant correlations were identified between IL-6 vs. CK-14 and IL-6 vs. MUC-3, MUC-3 vs. CK-14 and MUC-3 vs. MUC-5AC, and for MUC-1 vs. MUC-5AC. The correlation between IL-6 and CK-14 was also significant within the control and non-erosive reflux groups. The correlation between IL-6 and MUC-3 was significant within the control and erosive reflux groups, and the correlation between MUC-1 and MUC-5AC was significant within the erosive reflux group.

CONCLUSIONS

The results of this study suggest that the profile of mucin expression in the esophageal mucosa is influenced by the pH and composition of the gastro-esophageal reflux. Further work should explore the response of these genes to acid and bile reflux, and their role in the etiology of mucosal damage in gastro-esophageal reflux.

Meta analysis: Cancer risk in Barrett's oesophagus

BACKGROUND

Risk of cancer in Barrett's oesophagus is reported to vary between studies and also between countries, where the studies were conducted as per several systematic reviews. Cancer incidence has implications on surveillance strategies.

AIM

To perform a meta-analysis to determine the incidence of oesophageal cancer in Barrett's oesophagus.

METHODS

Articles retrieved by MEDLINE search (English language, 1966-2004). Studies had to necessarily include verified Barrett's oesophagus surveillance patients, documented follow-up and cancer identified as the outcome measure. A random effects model of meta-analysis was chosen and results were expressed as mean (95% CI).

RESULTS

Forty-one articles selected for conventional Barrett's oesophagus (length >3 cm); eight included short segment Barrett's oesophagus (one additional article including only short segment Barrett's oesophagus). Cancer incidence was 7/1000 (6-9) person-years duration of follow-up (pyd), with no detectable geographical variation [UK 7/1000 (4-12) pyd, USA 7/1000 (5-9) pyd and Europe 8/1000 (5-12) pyd]. Cancer incidence in the UK was 10/1000 (7-14), when two large studies were excluded. Cancer incidence in SSBO was 6/1000 (3-12) pyd. When short segment Barrett's oesophagus compared to conventional Barrett's oesophagus, there was a trend towards reduced cancer risk [OR 0.55, (95% CI: 0.19-1.6), P = 0.25].

CONCLUSION

We found no geographical variations in Barrett's oesophagus cancer risk, but observed a trend towards reduced cancer risk in short segment Barrett's oesophagus. There is a time trend of decreasing cancer incidence.

Investigation of genomic instability in paediatric Barrett's oesophagus using laser microdissection on paraffin-embedded endoscopic biopsies

OBJECTIVES

To investigate the occurrence of microsatellite instability (MSI) in paediatric Barrett's oesophagus (BE) with the aim of identifying a potential marker for patients at risk for developing dysplasia or adenocarcinoma at a later stage.

PATIENTS AND METHODS

Endoscopic oesophageal biopsies from 6 pediatric patients harbouring BE and 6 age-matched controls were retrospectively investigated. After all of the samples were made anonymous, a 5-microm section was cut and stained with toluidine blue. A precise cell was selected and captured using a laser microdissection microscope. Microsatellite analysis was performed on the DNA extracted from the captured cells. Genomic DNA was amplified by polymerase chain reaction using primers for 5 mononucleotide repeats and analysed by GeneMapper software on an ABI 3730. DNA extracted from a formalin-fixed colonic adenocarcinoma known to have MSI was used as a positive control.

RESULTS

The median age of the patients with BE was 9 years. The relevant complaint was long-standing vomiting in 4 cases and history of dysphagia in 3 cases (1 case had both symptoms). All of the cases had a history of reflux oesophagitis with histological confirmation of oesophagitis. Reflux was associated with a hiatus hernia, obesity, and cerebral palsy in each of 3 cases, and with asthma in 2 patients. Histologically, all of the cases showed the presence of specialized intestinal metaplasia containing goblet cells replacing the squamous oesophageal epithelium. None of the cases tested showed any evidence of MSI.

CONCLUSIONS

A single molecular marker that would allow recognition of those patients at risk for Barrett's adenocarcinoma has not yet been identified. The absence of MSI in our cases could be due to the need for a longer period of BE before genomic instability develops, or MSI may only arise in a proportion of patients. This does not exclude other genetic alterations, however rare they may be.

The Veneto Region's Barrett's Oesophagus Registry: aims, methods, preliminary results

BACKGROUND

The natural history of Barrett's Oeosphagus is not completely clarified and Barrett's Oeosphagus Registries are considered useful tools to expand our knowledge on this disease. A Barrett's Oeosphagus Registry has been therefore established in the Veneto Region and neighbouring provinces.

AIMS

The aims of the Registry are to assess the demographical, endoscopical and histological characteristics of Barrett's Oeosphagus patients; the prevalence of non-invasive neoplasia and Barrett's Adenocarcinoma and the timing and incidence of Barrett's Oeosphagus progression to malignancy.

METHODS

An interdisciplinary committee of endoscopists, pathologists and information technology experts was established in 2004 to design a website-based Barrett's Oesophagus Registry for the Veneto Region and neighbouring north-eastern Italian provinces. Protocols for endoscopies and biopsies and standard reports were carefully defined.

RESULTS

In the first 18 months, 397 patients with endoscopically visible and histologically proven Barrett's Oeosphagus were enrolled in the Registry; the median age of these patients was 66 years (male:female=3:1). Most patients (75%) had a Short Segment of Barrett's Oesophagus (<or=3 cm) and only 1 in 4 had a Long Segment of Barrett's Oesophagus (>3 cm). Long Segment of Barrett's Oesophagus patients were 5 years older than the Short Segment of Barrett's Oesophagus patients (p<0.05), suggesting a progression from Short Segment of Barrett's Oesophagus to Long Segment of Barrett's Oesophagus. Though no data are available on the incidence of non-invasive neoplasia or Barrett's Adenocarcinoma (i.e., progression to cancer at least 12 months after enrolment), the prevalence of neoplastic lesions (found within 12 months of enrolment) was 5% for Short Segment of Barrett's Oesophagus and 19% for Long Segment of Barrett's Oesophagus, indicating that a careful multiple-biopsy endoscopic protocol is needed, especially when Long Segment of Barrett's Oesophagus are suspected at endoscopy. The prevalence of Barrett's Adenocarcinoma among patients with non-invasive neoplasia was 1/17 cases of low-grade non-invasive neoplasia and 2/3 cases of high-grade non-invasive neoplasia, indicating that these patients require strict endoscopic and bioptic follow-up.

CONCLUSION

A regional Barrett's Oeosphagus Registry is feasible at a relatively low cost and enables significant data to be collected in a relatively short time. The use of a standardised endoscopic nomenclature and report form, a strict biopsy protocol, a standard report for pathologists improves the quality of endoscopic and histological diagnoses.

Expression profile of malignant and nonmalignant lesions of esophagus and stomach: differential activity of functional modules related to inflammation and lipid metabolism

Adenocarcinomas of stomach and esophagus are frequently associated with preceding inflammatory alterations of the normal mucosa. Whereas intestinal metaplasia of the gastric mucosa is associated with higher risk of malignization, Barrett's disease is a risk factor for adenocarcinoma of the esophagus. Barrett's disease is characterized by the substitution of the squamous mucosa of the esophagus by a columnar tissue classified histopathologically as intestinal metaplasia. Using cDNA microarrays, we determined the expression profile of normal gastric and esophageal mucosa as well as intestinal metaplasia and adenocarcinomas from both organs. Data were explored to define functional alterations related to the transformation from squamous to columnar epithelium and the malignant transformation from intestinal metaplasia to adenocarcinomas. Based on their expression profile, adenocarcinomas of the esophagus showed stronger correlation with intestinal metaplasia of the stomach than with Barrett's mucosa. Second, we identified two functional modules, lipid metabolism and cytokine, as being altered with higher statistical significance. Whereas the lipid metabolism module is active in samples representing intestinal metaplasia and inactive in adenocarcinomas, the cytokine module is inactive in samples representing normal esophagus and esophagitis. Using the concept of relevance networks, we determined the changes in linear correlation of genes pertaining to these two functional modules. Exploitation of the data presented herein will help in the precise molecular characterization of adenocarcinoma from the distal esophagus, avoiding the topographical and descriptive classification that is currently adopted, and help with the proper management of patients with Barrett's disease.