Barrett's oesophagus: epidemiology, cancer risk and implications for management

Effects of socioeconomic status on esophageal adenocarcinoma stage at diagnosis, receipt of treatment, and survival: A population-based cohort study

The incidence of esophageal adenocarcinoma (EAC) is increasing worldwide and has overtaken squamous histology in occurrence. We studied the impact of socioeconomic status (SES) on EAC stage at diagnosis, receipt of treatment, and survival. A population-based retrospective cohort study was conducted using Ontario Cancer Registry-linked administrative health data. Multinomial logistic regression was used to examine the association between SES (income quintile) and stage at EAC diagnosis and EAC treatment. Survival times following EAC diagnosis were estimated using Kaplan-Meier method. Cox proportional-hazards regression analysis was used to examine the association between SES and EAC survival. Between 2003–2012, 2,125 EAC cases were diagnosed. Median survival for the lowest-SES group was 10.9 months compared to 11.6 months for the highest-SES group; the 5-year survival was 9.8% vs. 15.0%. Compared to individuals in the highest-SES group, individuals in the lowest-SES category experienced no significant difference in EAC treatment (91.6% vs. 93.3%, P = 0.314) and deaths (78.9% vs. 75.6%, P = 0.727). After controlling for covariates, no significant associations were found between SES and cancer stage at diagnosis and EAC treatment. Additionally, after controlling for age, gender, urban/rural residence, birth country, health region, aggregated diagnosis groups, cancer stage, treatment, and year of diagnosis, no significant association was found between SES and EAC survival. Moreover, increased mortality risk was observed among those with older age (P = 0.001), advanced-stage of EAC at diagnosis (P < 0.001), and those receiving chemotherapy alone, radiotherapy alone, or surgery plus chemotherapy (P < 0.001). Adjusted proportional-hazards model findings suggest that there is no association between SES and EAC survival. While the unadjusted model suggests reduced survival among individuals in lower income quintiles, this is no longer significant after adjusting for any covariate. Additionally, there is an apparent association between SES and survival when considering only those individuals diagnosed with stage 0-III EAC. These analyses suggest that the observed direct relationship between SES and survival is explained by patient-level factors including receipt of treatment, something that is potentially modifiable.

Fatty acids in a high-fat diet potentially induce gastric parietal-cell damage and metaplasia in mice

BACKGROUND

Obesity is associated with risk of adenocarcinoma in the proximal stomach. We aimed to identify the links between dietary fat and gastric premalignant lesions.

METHODS

C57BL/6 mice were fed high fat diet (HFD), and gastric mucosa was histologically analysed. Morphological changes were also analysed using an electron microscope. Transcriptome analysis of purified parietal cells was performed, and non-parietal gastric corpus epithelial cells were subjected to single-cell gene-expression profiling. Composition of gastric contents of HFD-fed mice was compared with that of the HFD itself. Lipotoxicity of free fatty acids (FFA) was examined in primary culture and organoid culture of mouse gastric epithelial cells in vitro, as well as in vivo, feeding FFA-rich diets.

RESULTS

During ~8-20 weeks of HFD feeding, the parietal cells of the stomach displayed mitochondrial damage, and a total of 23% of the mice developed macroscopically distinct metaplastic lesions in the gastric corpus mucosa. Transcriptome analysis of parietal cells indicated that feeding HFD enhanced pathways related to cell death. Histological analysis and gene-expression profiling indicated that the lesions were similar to previously reported precancerous lesions identified as spasmolytic polypeptide-expressing metaplasia. FFAs, including linoleic acid with refluxed bile acids were detected in the stomachs of the HFD-fed mice. In vitro, FFAs impaired mitochondrial function and decreased the viability of parietal cells. In vivo, linoleic acid-rich diet, but not stearic acid-rich diet induced parietal-cell loss and metaplastic changes in mice.

CONCLUSIONS

Dietary lipids induce parietal-cell damage and may lead to the development of precancerous metaplasia.

The evolution and outcome of surveillance of Barrett's oesophagus over four decades in a UK District General Hospital

INTRODUCTION

We present the long-term outcome of Barrett's oesophagus (BO) at a District General Hospital set against the increasing numbers of patients with gastro-oesophageal reflux disease (GORD).

METHODS

Data were collected prospectively over 37 years. Comparison of GORD without Barrett's (NoBO) versus BO was performed from 1/1/1977 to 31/12/2001 when the NoBO database closed and outcomes of all cases of BO diagnosed until 31/12/2011 and followed up until 31/12/2013 have been reported.

RESULTS

During the period 1977-2001 the number of GORD NoBO cases was 11 610, and that of BO cases was 764 (6.2% of all GORD); total number of BO cases in 1977-2011 was 1468. NoBO patients were younger than BO patients: 52.2 versus 61.6 years. There was a male predominance in both groups: NoBO 55% and BO 62% (P<0.0001). The prevalence of oesophageal adenocarcinoma (OAC) was 87/1468 (5.9%) BO cases. Its incidence was 54/1381 (3.9%); the mean interval between the diagnosis of BO and incident OAC was 9 years (range 13 months-25.4 years); there was one OAC per 192 patient-years of follow-up (0.52% per year). Mortality was significantly lower in 37 patients under endoscopic surveillance at the time OAC was diagnosed (51 vs. 88% P=0.0141) partly because of older age and comorbidity of the other 17, in whom serial endoscopy was contraindicated. A proportional hazards model to allow for age estimated that the hazard rate ratio was lower in the surveillance group; however, this difference did not reach statistical significance (0.64, 95% confidence interval 0.30-1.48, P=0.08). Excluding prevalent cancers from both groups, mortality in BO was double that in NoBO (47 vs. 24%).

CONCLUSION

These 37 years of observation suggest, but do not confirm, that endoscopic surveillance may reduce the risk of death from OAC. Modern technology is likely to yield better results, but larger prospective studies are needed to confirm the benefits.

Progression of Barrett's esophagus toward esophageal adenocarcinoma: an overview

In Barrett's esophagus, normal squamous epithelium is replaced by a metaplastic columnar epithelium as a consequence of chronic gastroesophageal reflux disease. There is a strong association with esophageal adenocarcinoma. In view of the increasing incidence of esophageal adenocarcinoma in the western world, it is important that more attention be paid to the progression of Barrett's esophagus toward esophageal adenocarcinoma. Recently, several molecular factors have been identified that contribute to the sequence towards adenocarcinoma. This might help identify patients at risk and detect new targets for the prevention and treatment of esophageal adenocarcinoma in the future.

Contribution of immunomodulators to gastroesophageal reflux disease and its complications: stromal cells, interleukin 4, and adiponectin

Gastroesophageal reflux disease (GERD) has become the most commonly seen gastrointestinal disorder in outpatient clinics. In the United States, around 20% of the general population experience heartburn on a weekly basis. Although clinical complaints can be mild or moderate, patients with GERD may develop further complications, such as peptic strictures, Barrett's esophagus (BE), and even esophageal adenocarcinoma. Pathologically, GERD is developed as a result of chronic and enhanced exposure of the esophageal epithelium to noxious gastric refluxate. In this review article, we provide an overview of GERD and then focus on the roles of stromal cells, interleukin 4, and adiponectin in GERD and BE. The importance of inflammation and immunomodulators in GERD pathogenesis is highlighted. Targeting the immunomodulators or inflammation in general may improve the therapeutic outcome of GERD, in particular, in those refractory to proton pump inhibitors.

Metabolic syndrome is associated with increased risk of Barrett esophagus: A meta-analysis

BACKGROUND

Barrett esophagus (BE) is considered precursor condition of esophageal adenocarcinoma. Its incidence and prevalence are increasing in general population. Studies reported that metabolic syndrome (MS) or diabetes mellitus (DM) is related to increased risk of BE. Current study was to assess and better understand the relationship between MS /DM and BE.

METHODS

Electronic search was conducted in the database Pubmed/Medline (-December, 2015), Embase (-December, 2015), Cochrane Library (-December, 2015), and Web of Knowledge (-December, 2015). Studies included were assessed with summary odds ratios (ORs) with 95% confidence intervals (CIs) and compared exposure group with control group. The heterogeneity was examined by the funnel plot and the Egger's test. Subgroup analyses and sensitive analyses were performed for the detection of possible heterogeneity and impact on stability of analysis results.

RESULTS

Twelve publications met the criteria and included 355,311 subjects were analyzed. The pooled results showed MS was closely associated with increased risk of BE (OR = 1.23; 95%CI 1.03-1.47; P = 0.024), and yet DM did not significantly increase the risk of BE (OR = 1.07; 95%CI 0.82-1.38; P = 0.627). Substantial heterogeneities were detected. No significant publication bias was detected by Egger's test (P = 0.23).

CONCLUSIONS

Based on the results of current meta-analysis, MS is associated with increased risk of BE. Further long-term follow-up prospective study needs to verify the current results, and definite pathophysiological mechanism needs to be further investigated and clearly elucidated.

Acetic acid chromoendoscopy: Improving neoplasia detection in Barrett's esophagus

Barrett’s esophagus (BE) is an important condition given its significant premalignant potential and dismal five-year survival outcomes of advanced esophageal adenocarcinoma. It is therefore suggested that patients with a diagnosis of BE undergo regular surveillance in order to pick up dysplasia at an earlier stage to improve survival. Current “gold-standard” surveillance protocols suggest targeted biopsy of visible lesions followed by four quadrant random biopsies every 2 cm. However, this method of Barrett’s surveillance is fraught with poor endoscopist compliance as the procedures are time consuming and poorly tolerated by patients. There are also significant miss-rates with this technique for the detection of neoplasia as only 13% of early neoplastic lesions appear as visible nodules. Despite improvements in endoscope resolution these problems persist. Chromoendoscopy is an extremely useful adjunct to enhance mucosal visualization and characterization of Barrett’s mucosa. Acetic acid chromoendoscopy (AAC) is a simple, non-proprietary technique that can significantly improve neoplasia detection rates. This topic highlight summarizes the current evidence base behind AAC for the detection of neoplasia in BE and provides an insight into the direction of travel for further research in this area.

Acetic acid chromoendoscopy: Improving neoplasia detection in Barrett's esophagus

Barrett's esophagus (BE) is an important condition given its significant premalignant potential and dismal five-year survival outcomes of advanced esophageal adenocarcinoma. It is therefore suggested that patients with a diagnosis of BE undergo regular surveillance in order to pick up dysplasia at an earlier stage to improve survival. Current "gold-standard" surveillance protocols suggest targeted biopsy of visible lesions followed by four quadrant random biopsies every 2 cm. However, this method of Barrett's surveillance is fraught with poor endoscopist compliance as the procedures are time consuming and poorly tolerated by patients. There are also significant miss-rates with this technique for the detection of neoplasia as only 13% of early neoplastic lesions appear as visible nodules. Despite improvements in endoscope resolution these problems persist. Chromoendoscopy is an extremely useful adjunct to enhance mucosal visualization and characterization of Barrett's mucosa. Acetic acid chromoendoscopy (AAC) is a simple, non-proprietary technique that can significantly improve neoplasia detection rates. This topic highlight summarizes the current evidence base behind AAC for the detection of neoplasia in BE and provides an insight into the direction of travel for further research in this area.

Rates and predictors of progression to esophageal carcinoma in a large population-based Barrett's esophagus cohort

BACKGROUND AND AIMS

Rates of progression to esophageal adenocarcinoma in subjects with Barrett's esophagus (BE) are lower than previously estimated. Identification of predictors of progression will enable risk stratification of BE subjects, potentially making current surveillance programs more efficient. We aimed to assess the potential of demographic and lifestyle factors, obesity, and medications in predicting progression in BE.

METHODS

BE subjects were identified from the General Practice Research Database using validated diagnostic codes. BE subjects developing esophageal cancer (EC) 12 months after their index BE diagnosis were defined as progressors. Time-to-event analysis was used to assess the overall risk of progression to EC. Cox proportional hazards models and time-varying marginal structural models were used to assess predictors of progression.

RESULTS

Included in the analysis were 9660 BE patients. The mean age (SD) of the study subjects was 63 (13.5) years; 62.6% were men. One hundred three subjects (1.1%) progressed to EC. The mean (SD) follow-up since initial diagnosis was 4.8 (3.3) years. The incidence of EC was 2.23 per 1000 person-years of follow-up. Increasing age, male gender, and being overweight (body mass index, 25-29.9) were found to be independent predictors of progression. When time-varying models were used, proton pump inhibitor (PPI) and statin use were protective against progression.

CONCLUSIONS

In this large population-based cohort of patients with BE, increasing age, male gender, and being overweight predicted progression to EC, whereas PPI and statin use were protective against EC development. These factors may aid in developing a risk score to predict the risk of progression and chemopreventive strategies in patients with BE.

Risk factors for Barrett's esophagus: a scoping review

INTRODUCTION

Cancer of the esophagus is a highly lethal disease with many patients presenting with metastatic spread of their tumor at diagnosis; a consequence of this late presentation is the 5-year survival rate of <20 %. Barrett's esophagus (BE), a premalignant condition of the distal esophagus, is the main risk factor for adenocarcinoma of the esophagus. The development of a risk prediction tool that could assist healthcare professionals in identifying people at increased risk of developing BE would be advantageous. Understanding the factors that influence the risk of developing BE is the first stage of developing a risk prediction tool.

METHODS

A scoping review was undertaken to address the following question 'what factors influence the risk of developing Barrett's esophagus?' Forty-six articles were included in this review.

RESULTS

The majority of articles reviewed were case-control or cohort studies. Samples sizes ranged from 68 to 84,606. Risk factors reported to be statistically significant were divided into three categories: demographic, lifestyle and clinical factors. Strongest risk factors identified include: male gender, increasing age, white race, smoking, obesity and gastro-esophageal reflux disease symptoms, while some aspects of a person's diet appear to act as a protective measure.

CONCLUSION

Risk factors for BE are complex and need to be considered by healthcare professionals when identifying patients that could benefit from endoscopic eradication. These results provide a stepping stone for the future development of a risk prediction model.

Length of Barrett's oesophagus and cancer risk: implications from a large sample of patients with early oesophageal adenocarcinoma

OBJECTIVE

Although it is well understood that the risk of oesophageal adenocarcinoma increases with Barrett length, transition risks for cancer associated with different Barrett lengths are unknown. We aimed to estimate annual cancer transition rates for patients with long-segment (≥3 cm), short-segment (≥1 to <3 cm) and ultra-short-segment (<1 cm) Barrett's oesophagus.

DESIGN

We used three data sources to estimate the annual cancer transition rates for each Barrett length category: (1) the distribution of long, short and ultra-short Barrett's oesophagus among a large German cohort with newly diagnosed T1 oesophageal adenocarcinoma; (2) population-based German incidence of oesophageal adenocarcinoma; and (3) published estimates of the population prevalence of Barrett's oesophagus for each Barrett length category.

RESULTS

Among 1017 patients with newly diagnosed T1 oesophageal adenocarcinoma, 573 (56%) had long-segment, 240 (24%) short-segment and 204 (20%) ultra-short-segment Barrett's oesophagus. The base-case estimates for the prevalence of Barrett's oesophagus among the general population were 1.5%, 5% and 14%, respectively. The annual cancer transition rates for patients with long, short and ultra-short Barrett's oesophagus were 0.22%, 0.03% and 0.01%, respectively. To detect one cancer, 450 patients with long-segment Barrett's oesophagus would need to undergo annual surveillance endoscopy; in short segment and ultra-short segment, the corresponding numbers of patients would be 3440 and 12,364. Similar results were obtained when applying US incidence data.

CONCLUSIONS

The large number of patients, who need to undergo endoscopic surveillance to detect one cancer, raises questions about the value of surveillance endoscopy in patients with short segment or ultra-short segment of Barrett's oesophagus.

Advances in the endoscopic diagnosis and treatment of Barrett's neoplasia

Barrett's oesophagus is a well-recognised precursor of oesophageal adenocarcinoma. The incidence of oesophageal adenocarcinoma is continuing to rise in the Western world with dismal survival rates. In recent years, efforts have been made to diagnose Barrett's earlier and improve surveillance techniques in order to pick up cancerous changes earlier. Recent advances in endoscopic therapy for early Barrett's cancers have shifted the paradigm away from oesophagectomy and have yielded excellent results.

The Effect of Campylobacter concisus on Expression of IL-18, TNF-α and p53 in Barrett's Cell Lines

BACKGROUND

Barrett's oesophagus is a pre-malignant condition at gastroesophageal junction in which normal squamous epithelium is replaced by columnar shape epithelium, which predisposes oesophageal adenocarcinoma. It is known that Barrett's oesophagus evolves as a consequence of chronic gastro-oesophageal reflux disease. Although progression of Barrett's oesophagus to adenocarcinoma is still unclear, increasing incidence of oesophageal cancer and mortality worldwide make its study necessary. Several investigations have been made on the aetiology of oesophageal cancer. Most of them assessed genetical or environmental factors. However, potential role of bacteria in the development of oesophageal adenocarcinoma as a new environmental factor has not been addressed. Previous study on Barrett's disease detected presence of Campylobacter concisus as a new emerging pathogen on Barrett's and oesophageal cancer samples compared with healthy individuals. This indicates that this organism might involve in the progression of Barrett's to oesophageal adenocarcinoma.

OBJECTIVES

This study aimed to determine the effects of C. concisus on expression of three biomarkers including interleukin-18 (IL-18), tumour necrosis factor-α (TNF-α) and tumour suppressor gene (p53) in three Barrett's cell lines.

MATERIALS AND METHODS

Quantitative real-time PCR assays were developed to measure expression of pro-inflammatory mediators (IL-18 and TNF-α) and gene expression of p53 in Barrett's cell lines in co-culture with C. concisus.

RESULTS

The mentioned organism was able to modulate considerably expression of p53, TNF-α and IL-18 in a time-dependent manner.

CONCLUSIONS

The results showed that microorganism influences expression of carcinogenesis biomarker and cytokines in cell line models and possibility promotes oesophageal adenocarcinoma.

Emerging optical methods for surveillance of Barrett's oesophagus

The rapid rise in incidence of oesophageal adenocarcinoma has motivated the need for improved methods for surveillance of Barrett's oesophagus. Early neoplasia is flat in morphology and patchy in distribution and is difficult to detect with conventional white light endoscopy (WLE). Light offers numerous advantages for rapidly visualising the oesophagus, and advanced optical methods are being developed for wide-field and cross-sectional imaging to guide tissue biopsy and stage early neoplasia, respectively. We review key features of these promising methods and address their potential to improve detection of Barrett's neoplasia. The clinical performance of key advanced imaging technologies is reviewed, including (1) wide-field methods, such as high-definition WLE, chromoendoscopy, narrow-band imaging, autofluorescence and trimodal imaging and (2) cross-sectional techniques, such as optical coherence tomography, optical frequency domain imaging and confocal laser endomicroscopy. Some of these instruments are being adapted for molecular imaging to detect specific biological targets that are overexpressed in Barrett's neoplasia. Gene expression profiles are being used to identify early targets that appear before morphological changes can be visualised with white light. These targets are detected in vivo using exogenous probes, such as lectins, peptides, antibodies, affibodies and activatable enzymes that are labelled with fluorescence dyes to produce high contrast images. This emerging approach has potential to provide a 'red flag' to identify regions of premalignant mucosa, outline disease margins and guide therapy based on the underlying molecular mechanisms of cancer progression.

Definition of Barrett's esophagus dysplasia: are we speaking the same language?

The definition of Barrett's esophagus (BE) is still a matter of debate. The diagnostic criteria adopted around the world for both BE and BE-related pre-cancerous lesions are inconsistent, particularly between Eastern and Western pathologists. From a clinical perspective, these different clinico-biological approaches may affect how the literature is interpreted, with detrimental effects on the clinical management of patients. The present review focuses on the major discrepancies in the field, covering both the non-neoplastic and the pre-cancerous lesions associated with Barrett's disease.

Barrett's Oesophagus Surveillance versus endoscopy at need Study (BOSS): protocol and analysis plan for a multicentre randomized controlled trial

OBJECTIVES

The absolute annual risk of patients with Barrett's oesophagus (BO) developing oesophageal adenocarcinoma (OAC) is ≤ 0.5%. Screening BO patients for malignant progression using endoscopic surveillance is widely practised. To assess the efficacy and cost-effectiveness of this, we developed a protocol for a randomized controlled trial of surveillance versus 'at need' endoscopy.

METHODS

In a multicentre trial, 3400 BO patients randomized to either 2-yearly endoscopic surveillance or 'at need' endoscopy will be followed up for 10 years. Urgent endoscopy will be offered to all patients who develop symptoms of dysphagia, unexplained weight loss > 7lb (3.2 kg), iron deficiency anaemia, recurrent vomiting, or worsening upper gastrointestinal symptoms. Participants must have endoscopically and histologically confirmed BO, with circumferential BO ≥ 1 cm or maximal tongue/island length ≥ 2 cm. Candidates with existing oesophageal high-grade dysplasia or cancer, or previous upper gastrointestinal cancer will be excluded. Primary outcome will be overall survival. Secondary outcomes will be cost effectiveness (cost per life year saved and quality adjusted life years); cancer-specific survival; time to OAC diagnosis and stage at diagnosis; morbidity and mortality related to any interventions; and frequency of endoscopy.

CONCLUSIONS

This randomized trial will provide data to evaluate the efficacy and cost-effectiveness of screening BO patients for OAC.

Esophageal development and epithelial homeostasis

The esophagus is a relatively simple organ that evolved to transport food and liquids through the thoracic cavity. It is the only part of the gastrointestinal tract that lacks any metabolic, digestive, or absorptive function. The mucosa of the adult esophagus is covered by a multilayered squamous epithelium with a remarkable similarity to the epithelium of the skin despite the fact that these tissues originate from two different germ layers. Here we review the developmental pathways involved in the establishment of the esophagus and the way these pathways regulate gut-airway separation. We summarize current knowledge of the mechanisms that maintain homeostasis in esophageal epithelial renewal in the adult and the molecular mechanism of the development of Barrett's metaplasia, the precursor lesion to esophageal adenocarcinoma. Finally, we examine the ongoing debate on the hierarchy of esophageal epithelial precursor cells and on the presence or absence of a specific esophageal stem cell population. Together the recent insights into esophageal development and homeostasis suggest that the pathways that establish the esophagus during development also play a role in the maintenance of the adult epithelium. We are beginning to understand how reflux of gastric content and the resulting chronic inflammation can transform the squamous esophageal epithelium to columnar intestinal type metaplasia in Barrett's esophagus.

Circulating Serum Exosomal miRNAs As Potential Biomarkers for Esophageal Adenocarcinoma

BACKGROUND

The poor prognosis and rising incidence of esophageal adenocarcinoma highlight the need for improved detection methods. The potential for circulating microRNAs (miRNAs) as biomarkers in other cancers has been shown, but circulating miRNAs have not been well characterized in esophageal adenocarcinoma. We investigated whether circulating exosomal miRNAs have potential to discriminate individuals with esophageal adenocarcinoma from healthy controls and non-dysplastic Barrett's esophagus.

METHODS

Seven hundred fifty-eight miRNAs were profiled in serum circulating exosomes from a cohort of 19 healthy controls, 10 individuals with Barrett's esophagus, and 18 individuals with locally advanced esophageal adenocarcinoma. MiRNA expression was assessed using all possible permutations of miRNA ratios per individual. Four hundred eight miRNA ratios were differentially expressed in individuals with cancer compared to controls and Barrett's esophagus (Mann-Whitney U test, P < 0.05). The 179/408 ratios discriminated esophageal adenocarcinoma from healthy controls and Barrett's esophagus (linear regression, P < 0.05; area under receiver operating characteristic (ROC) > 0.7, P < 0.05). A multi-biomarker panel (RNU6-1/miR-16-5p, miR-25-3p/miR-320a, let-7e-5p/miR-15b-5p, miR-30a-5p/miR-324-5p, miR-17-5p/miR-194-5p) demonstrated enhanced specificity and sensitivity (area under ROC = 0.99, 95% CI 0.96-1.0) over single miRNA ratios to distinguish esophageal adenocarcinoma from controls and Barrett's esophagus.

CONCLUSIONS

This study highlights the potential for serum exosomal miRNAs as biomarkers for the detection of esophageal adenocarcinoma.

Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC), a disease with increasing burden in the Western world, especially in white men. Risk factors for BE include obesity, tobacco smoking, and gastroesophageal reflux disease (GERD). EAC is the most common form of esophageal cancer in the United States. Risk factors include GERD, tobacco smoking, and obesity, whereas nonsteroidal antiinflammatory drugs and statins may be protective. Factors predicting progression from nondysplastic BE to EAC include dysplastic changes on esophageal histology and length of the involved BE segment. Biomarkers have shown promise, but none are approved for clinical use.

Androgens and esophageal cancer: What do we know?

Significant disparities exist between genders for the development and progression of several gastro-intestinal (GI) diseases including cancer. Differences in incidence between men vs women for colon, gastric and hepatocellular cancers suggest a role for steroid sex hormones in regulation of GI carcinogenesis. Involvement of intrinsic gender-linked mechanisms is also possible for esophageal adenocarcinoma as its incidence is disproportionally high among men. However, the cause of the observed gender differences and the potential role of androgens in esophageal carcinogenesis remains unclear, even though the cancer-promoting role of androgen receptors (AR) shown in other cancers such as prostate and bladder suggests this aspect warrants exploration. Several studies have demonstrated expression of ARs in esophageal cancer. However, only one study has suggested a potential link between AR signaling and outcome - poorer prognosis. Two groups have analyzed data from cohorts with prostate cancer and one of these found a decreased incidence of esophageal squamous and adenocarcinoma after androgen deprivation therapy. However, very limited information is available about the effects of androgen and AR-initiated signaling on esophageal cancer cell growth in vitro and in vivo. Possible mechanisms for androgens/AR involvement in the regulation of esophageal cancer growth are considered, and the potential use of AR as a prognostic factor and clinical target is highlighted, although insufficient evidence is available to support clinical trials of novel therapies. As esophageal adenocarcinoma is a gender linked cancer with a large male predominance further studies are warranted to clarify the role of androgens and ARs in shaping intracellular signaling and genomic responses in esophageal cancer.

Early metal stent insertion fails to prevent stricturing after single-stage complete Barrett's excision for high-grade dysplasia and early cancer

BACKGROUND

Barrett's esophagus with high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) can be effectively treated by single-session EMR, resulting in complete Barrett's excision (CBE). CBE provides accurate histology for staging and clinical confirmation of neoplasia eradication but is limited by a high risk of esophageal stricture formation.

OBJECTIVE

To evaluate the effectiveness of prophylactic temporary esophageal stenting to prevent post-CBE stricture formation.

DESIGN AND SETTING

Single-center, investigator-initiated feasibility study.

PATIENTS

Circumferential, short-segment Barrett's esophagus (≤C3≤M5) with HGD or IMC.

INTERVENTION

Single-stage CBE and insertion of a fully covered metal esophageal stent at 10 days that was removed at 8 weeks. Patients were followed for a minimum of 2 surveillance endoscopies.

MAIN OUTCOME MEASUREMENT

Symptomatic esophageal stricture formation.

RESULTS

At the end of the follow-up period, 8 patients (57.1%) required esophageal dilation for symptomatic CBE-related (n = 7) or stent-related (n = 4) strictures. A median of 3 surveillance endoscopies were performed over a median endoscopic follow-up of 17 months (range 4-25 months). Single-stage CBE successfully eliminated Barrett's intestinal metaplasia and neoplasia in 71.4% and 92.9% of patients, respectively. Four patients were admitted to the hospital, and 4 patients had early stent removal because of pain or dysphagia.

LIMITATIONS

Single-center feasibility study.

CONCLUSIONS

In a prospective study evaluating prophylactic esophageal stent insertion after single-stage CBE, esophageal strictures formed in more than of half the study cohort, and stents were associated with significant morbidity. An alternative method to reduce stricture formation is required. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01554280.).

Barrett's oesophagus: how should we manage it?

Endoscopic surveillance remains the core management of non-dysplastic Barrett's oesophagus, although questions regarding its efficacy in reducing mortality from oesophageal adenocarcinoma have yet to be definitively answered, and randomised trial data are awaited. One of the main goals of current research is to achieve risk stratification, identifying those at high risk of progression. The recent British Society of Gastroenterology (BSG) guidelines on surveillance have taken a step in this direction with interval stratification on clinicopathological grounds. The majority of Barrett's oesophagus remains undiagnosed, and this has led to investigation of methods of screening for Barrett's oesophagus, ideally non-endoscopic methods capable of reliably identifying dysplasia. Chemoprevention to prevent progression is currently under investigation, and may become a key component of future treatment. The availability of effective endotherapy means that accurate identification of dysplasia is more important than ever. There is now evidence to support intervention with radiofrequency ablation (RFA) for low-grade dysplasia (LGD), but recent data have emphasised the need for consensus pathology for LGD. Ablative treatment has become well established for high-grade dysplasia, and should be employed for flat lesions where there is no visible abnormality. Of the ablative modalities, RFA has the strongest evidence base. Endoscopic resection should be performed for all visible lesions, and is now the treatment of choice for T1a tumours. Targeting those with high-risk disease will, hopefully, lead to efficacious and cost-effective surveillance, and the trend towards earlier intervention to halt progression gives cause for optimism that this will ultimately result in fewer deaths from oesophageal adenocarcinoma.

Screening for Barrett's esophagus and esophageal adenocarcinoma: rationale, recent progress, challenges, and future directions

As the incidence and mortality of esophageal adenocarcinoma continue to increase, strategies to counter this need to be explored. Screening for Barrett's esophagus, which is the known precursor of a large majority of adenocarcinomas, has been debated without a firm consensus. Given evidence for and against perceived benefits of screening, the multitude of challenges in the implementation of such a strategy and in the downstream management of subjects with Barrett's esophagus who could be diagnosed by screening, support for screening has been modest. Recent advances in the form of development and initial accuracy of noninvasive tools for screening, risk assessment tools, and biomarker panels to risk stratify subjects with BE, have spurred renewed interest in the early detection of Barrett's esophagus and related neoplasia, particularly with the advent of effective endoscopic therapy. In this review, we explore in depth the potential rationale for screening for Barrett's esophagus, recent advances that have the potential of making screening feasible, and also highlight some of the challenges that will have to be overcome to develop an effective approach to improve the outcomes of subjects with esophageal adenocarcinoma.

The epidemiology, diagnosis, and treatment of Barrett's carcinoma

BACKGROUND

Roughly 3000 new cases of Barrett's carcinoma arise in Germany each year. In view of recent advances in the epidemiology, diagnosis, and treatment of this disease, an update of the clinical recommendations is in order.

METHODS

This review is based on selected relevant publications, including current reviews, meta-analyses, and guidelines.

RESULTS

The risk of progression of Barrett's esophagus to carcinoma lies between 0.10% and 0.15% per year. Risk factors for progression include male sex, age over 50 years, obesity, longstanding and frequent reflux symptoms, smoking, length of the Barrett's esophagus, and intraepithelial neoplasia. Well-differentiated carcinomas that are confined to the esophageal mucosa can be resected endoscopically with a cure rate above 90%. For more advanced, but still locally confined tumors, surgical resection is the treatment of choice. In stages cT3/4, the prognosis can be improved with neo-adjuvant chemo - therapy or combined radiotherapy and chemotherapy. Metastatic Barrett's carcinoma can be treated by endoscopic, chemotherapeutic, radiotherapeutic, and palliative methods.

CONCLUSION

Early carcinoma can often be cured by endoscopic resection. Locally advanced carcinoma calls for multimodal treatment. Current research focuses on means of preventing the progression of Barrett's esophagus, the scope of applicability of endoscopic techniques, and the optimization of multimodal treatment strategies for advanced disease.

Bile acids but not acidic acids induce Barrett's esophagus

Barrett's esophagus (BE) is associated with the development of esophageal adenocarcinoma (EAC). Bile acids (BAs) refluxing into the esophagus contribute to esophageal injury, which results in BE and subsequent EAC. We developed two animal models to test the role of BAs in the pathogenesis of BE. We surgically generated BA reflux, with or without gastric acid, in rats. In a second experiment, we fed animals separately with BAs and gastric acid. Pathologic changes were examined and the expression of Muc2 and Cdx2 in BE tissue was tested by immunostaining. Inflammatory factors in the plasma, as well as differentiation genes in BE were examined through highly sensitive ELISA and semi-quantitative RT-PCR techniques. We found that BAs are sufficient for the induction of esophagitis and Barrett's-like metaplasia in the esophagus. Overexpression of inflammatory cells, IL-6, and TNF-α was observed both in animals fed with BAs and surgically generated BA reflux. Furthermore, elevated levels of Cdx2, Muc2, Bmp4, Kit19, and Tff2 (differentiation genes in BE) were found in BA-treated rats. In conclusion, BAs, but not gastric acid, are a major causative factor for BE. We confirmed that BAs contribute to the development of BE by inducing the inflammatory response in the esophagus. Inhibiting BAs may be a promising therapy for BE.

Acid suppression and surgical therapy for Barrett's oesophagus

Gastro-oesophageal reflux disease is a common medical problem in developed countries, and is a risk factor for the development of Barrett's oesophagus and oesophageal adenocarcinoma. Both proton pump inhibitor therapy and antireflux surgery are effective at controlling endoscopic signs and symptoms of gastro-oesophageal reflux in patients with Barrett's oesophagus, but often fail to eliminate pathological oesophageal acid exposure. The current available studies strongly suggest that acid suppressive therapy, both pharmacological as well as surgical acid suppression, can reduce the risk the development and progression in patients with Barrett's oesophagus, but are not capable of complete prevention. No significant differences have been found between pharmacological and surgical therapy. For clinical practice, patients should be prescribed a proton pump inhibitor once daily as maintenance therapy, with the dose guided by symptoms. Antireflux surgery can be a good alternative to proton pump inhibitor therapy, but should be primarily offered to patients with symptomatic reflux, and not to asymptomatic patients with the rationale to protect against cancer.

Mechanisms of Barrett's oesophagus (clinical): LOS dysfunction, hiatal hernia, peristaltic defects

Barrett's oesophagus, with the potential to develop into oesophageal adenocarcinoma (OAC), is a major complication of gastrooesophageal reflux disease (GORD). However, about 50% of patients developing OAC had no known GORD beforehand. Hence, while GORD symptoms, oesophagitis, and Barrett's have a number of common determinants (oesophagogastric junction (OGJ) incompetence, impaired oesophageal clearance mechanisms, hiatus hernia) they also have some independent determinants. Further, although excess oesophageal acid exposure plays a major role in the genesis of long-segment Barrett's oesophagus there is minimal evidence supporting this for short-segment Barrett's. Hence, these may have unique pathophysiological features as well. Long-segment Barrett's seems to share most, if not all, of the risk factors for oesophagitis, particularly high-grade oesophagitis. However, it is uncertain if OGJ function and acid clearance are more severely impaired in patients with long-segment Barrett's compared to patients with high-grade oesophagitis. With respect to short-segment Barrett's, the acid pocket may play an important pathogenic role. Conceptually, extension of the acid pocket into the distal oesophagus, also known as intra-sphincteric reflux, provides a mechanism or acid exposure of the distal osophageal mucosa without the occurrence of discrete reflux events, which are more likely to prompt reflux symptoms and lead to the development of oesophagitis. Hence, intra-sphincteric reflux related to extension of the acid/no acid interface at the proximal margin of the acid pocket may be key in the development of short segment Barrett's. However, currently this is still somewhat speculative and further studies are required to confirm this.

Epigenetics in the Pathogenesis of Esophageal Adenocarcinoma

Epigenetic influences, such as DNA methylation, histone acetylation, and up-regulation/down-regulation of genes by microRNAs, change the genetic makeup of an individual without affecting DNA base-pair sequences. Indeed, epigenetic changes play an integral role in the progression from normal esophageal mucosa to Barrett's esophagus to esophageal adenocarcinoma via dysplasia-metaplasia-neoplasia sequence. Many genes involved in esophageal adenocarcinoma display hypermethylation, leading to their down-regulation. The classes of these genes include cell cycle control, DNA and growth factor repair, tumor suppressors, antimetastasis, Wnt-related genes, and proapoptotic genes. Histone acetylation in the pathophysiology of esophageal diseases has not been thoroughly investigated, and its critical role in the development of esophageal adenocarcinoma is less defined. Many microRNAs have been associated with the development of Barrett's esophagus and esophageal adenocarcinoma. Here, we critically addressed the specific steps most closely influenced by microRNAs in the progression from Barrett's esophagus to esophageal adenocarcinoma. However, microRNAs can target up to hundreds of genes, making it difficult to correlate directly with a given phenotype of the disease. Esophageal adenocarcinoma progressing from premalignant condition of Barrett's esophagus carries an extremely poor prognosis. Risk stratification for patients based on their epigenetic profiles may be useful in providing more targeted and directed treatment to patients.

The past 10 years of gastroenterology and hepatology-reflections and predictions

In November 2004, the very first issue of this journal featured articles on the pathogenesis of ulcerative colitis, mechanisms leading to chronic pancreatitis, and treatment of recurrent Clostridium-difficile-associated diarrhoea. Although those topics might seem familiar, much has changed in the intervening years in our understanding, diagnosis and treatment of many different diseases across the field of gastroenterology and hepatology. Nonetheless, many challenges remain. Here, we have asked five of our Advisory Board members-international experts across different subspecialties in gastroenterology and hepatology-to reflect on the progress and frustrations of the past 10 years. They also comment on where effort and money should be invested now, as well as their predictions for progress in the next 10 years.

Endoscopic surveillance of gastrointestinal premalignant lesions: current knowledge and future directions

PURPOSE OF REVIEW

Provide an evidence-based resource for the surveillance of gastrointestinal premalignant lesions, focusing on the scientific articles reported recently.

RECENT FINDINGS

No randomized controlled clinical trials exist to definitively support the efficacy of surveillance programs for Barrett's esophagus and gastric intestinal metaplasia. However, surveillance of these premalignant lesions is recommended by some of the leading organizations. To optimize the usefulness of surveillance programs, targeting high-risk patients might maximize its benefits. A Barrett's esophagus segment of at least 3 cm and evidence of intestinal metaplasia can help stratify those patients at highest risk for progression to esophageal adenocarcinoma. The location, extent, and severity of intestinal metaplasia are indicators of risk of developing gastric cancer. Patients with extensive intestinal metaplasia should be offered endoscopic surveillance. Quality in the baseline colonoscopy is crucial to decrease the risk of interval colorectal cancers. The importance of serrated polyps, as well as their surveillance intervals, is emphasized.

SUMMARY

To optimize the usefulness of surveillance programs, targeting high-risk patients might maximize its benefits. Future research is needed to design more effective surveillance strategies. Recently, emerging imaging techniques hold promise for improving sensitivity of endoscopic surveillance of premalignant conditions in the gastrointestinal tract.

The use of imaging and biomarkers in diagnosing Barrett's esophagus and predicting the risk of neoplastic progression

Long-standing gastroesophageal reflux disease can result in transformation of the normal squamous lining of the esophagus into columnar epithelium (with goblet cells). This condition, Barrett's esophagus (BE), is considered a risk factor for esophageal cancer (EAC) and may be the cause of the increased incidence of EAC over the last few decades. Currently, endoscopy with biopsies revealing dysplasia is the best predictor for neoplastic progression in patients with BE. However, the use of more sophisticated imaging techniques and biomarkers with or without histological assessment may be helpful in more accurate prediction of malignant transformation in these patients. New approaches to the evaluation of BE such as epigenetics, miRNA analysis, detection of DNA content abnormalities and loss of heterozygosity have great potential to shed light on the complex gastroesophageal reflux disease -BE-EAC sequence.

Involvement of luminal nitric oxide in the pathogenesis of the gastroesophageal reflux disease spectrum

Over the last 3 decades, the incidence of esophageal adenocarcinoma has dramatically increased in Western countries; a similar increase may be observed in Asian countries in the near future. Esophageal adenocarcinoma arises from a sequential gastroesophageal reflux disease (GERD) spectrum from reflux erosive esophagitis, to Barrett's esophagus, and finally to esophageal adenocarcinoma. At present, gastric acid and bile are assumed to be primarily involved in the etiology of the GERD spectrum. We reported in 2002 that, at the gastroesophageal junction in humans, abundant amounts of nitric oxide (NO) are generated luminally through the entero-salivary re-circulation of dietary nitrate. Since then, we have carried out a series of experiments to demonstrate that NO diffuses into the adjacent epithelium at cytotoxic levels. This diffusion results in disruption of the epithelial barrier function, exacerbation of inflammation, acceleration of columnar transformation in the esophagus (Barrett's esophagus) via the induction of caudal-type homeobox 2, and the shifting of carcinogenic N-nitroso compound formation from the luminal to epithelial compartment. These results suggest that, in addition to conventionally recognized causative factors, luminal NO could also be involved in the pathogenesis of the GERD spectrum. In addition, we recently showed that there is a prominent gender-related difference in NO-related cytotoxicity in the esophagus and that estrogen attenuated the esophageal tissue damage via the estrogen receptor in female rats. The role of estrogen in attenuating the esophageal tissue damage in NO-related esophageal damage could explain the well-recognized male predominance in the GERD spectrum in humans.

Histopathology in barrett esophagus and barrett esophagus-related dysplasia

Pathologic specimens, both biopsies and endoscopic mucosal resections, for Barrett esophagus and Barrett-associated dysplasia and malignancy are common for pathologists in North America, and the incidence in South Asian countries seems to be increasing. Dysplasia and malignancy arising in intestinalized gastric-type mucosa raises issues in the interpretation of dysplasia and the evaluation of the depth of invasion of malignancies that are not seen in squamous dysplasia and squamous cell carcinoma. We review the North American approach to these lesions.