Epidemiologic Risk Factors in a Comparison of a Barrett Esophagus Registry (BarrettNET) and a Case-Control Population in Germany

Role of Obesity, Physical Exercise, Adipose Tissue-Skeletal Muscle Crosstalk and Molecular Advances in Barrett's Esophagus and Esophageal Adenocarcinoma

Both obesity and esophageal adenocarcinoma (EAC) rates have increased sharply in the United States and Western Europe in recent years. EAC is a classic example of obesity-related cancer where the risk of EAC increases with increasing body mass index. Pathologically altered visceral fat in obesity appears to play a key role in this process. Visceral obesity may promote EAC by directly affecting gastroesophageal reflux disease and Barrett’s esophagus (BE), as well as a less reflux-dependent effect, including the release of pro-inflammatory adipokines and insulin resistance. Deregulation of adipokine production, such as the shift to an increased amount of leptin relative to “protective” adiponectin, has been implicated in the pathogenesis of BE and EAC. This review discusses not only the epidemiology and pathophysiology of obesity in BE and EAC, but also molecular alterations at the level of mRNA and proteins associated with these esophageal pathologies and the potential role of adipokines and myokines in these disorders. Particular attention is given to discussing the possible crosstalk of adipokines and myokines during exercise. It is concluded that lifestyle interventions to increase regular physical activity could be helpful as a promising strategy for preventing the development of BE and EAC.

Evolutionary dynamics in Barrett oesophagus: implications for surveillance, risk stratification and therapy

Cancer development is a dynamic evolutionary process characterized by marked intratumoural heterogeneity at the genetic, epigenetic and phenotypic levels. Barrett oesophagus, the pre-malignant condition to oesophageal adenocarcinoma (EAC), is an exemplary system to longitudinally study the evolution of malignancy. Evidence has emerged of Barrett oesophagus lesions pre-programmed for progression to EAC many years before clinical detection, indicating a considerable window for therapeutic intervention. In this Review, we explore the mechanisms underlying clonal expansion and contraction that establish the Barrett oesophagus clonal mosaicism over time and space and discuss intrinsic genotypic and extrinsic environmental drivers that direct the evolutionary trajectory of Barrett oesophagus towards a malignant phenotype. We propose that understanding and exploiting the evolutionary dynamics of Barrett oesophagus will identify novel therapeutic targets, improve prognostic tools and offer the opportunity for personalized surveillance programmes geared to prevent progression to EAC.

[Prevention of gastrointestinal cancer]

Throughout the past decades, considerable progress has been made in the (early) diagnosis and treatment of gastrointestinal cancers. However, the prognosis for advanced stages of gastrointestinal tumors remains limited for many patients and approximately one third of all tumor patients die as a result of gastrointestinal tumors. The prevention and early detection of gastrointestinal tumors is therefore of great importance.For this reason, we summarize the current state of knowledge and recommendations for the primary, secondary and tertiary prevention of esophageal, stomach, pancreas, liver and colorectal cancer in the following.

Differences in Gut Virome Related to Barrett Esophagus and Esophageal Adenocarcinoma

The relationship between viruses (dominated by bacteriophages or phages) and lower gastrointestinal (GI) tract diseases has been investigated, whereas the relationship between gut bacteriophages and upper GI tract diseases, such as esophageal diseases, which mainly include Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC), remains poorly described. This study aimed to reveal the gut bacteriophage community and their behavior in the progression of esophageal diseases. In total, we analyzed the gut phage community of sixteen samples from patients with esophageal diseases (six BE patients and four EAC patients) as well as six healthy controls. Differences were found in the community composition of abundant and rare bacteriophages among three groups. In addition, the auxiliary metabolic genes (AMGs) related to bacterial exotoxin and virulence factors such as lipopolysaccharides (LPS) biosynthesis proteins were found to be more abundant in the genome of rare phages from BE and EAC samples compared to the controls. These results suggest that the community composition of gut phages and functional traits encoded by them were different in two stages of esophageal diseases. However, the findings from this study need to be validated with larger sample sizes in the future.

Global prevalence of Barrett's oesophagus and oesophageal cancer in individuals with gastro-oesophageal reflux: a systematic review and meta-analysis

OBJECTIVES

Chronic gastro-oesophageal reflux might lead to the development of Barrett's oesophagus (BO) or even oesophageal adenocarcinoma. There has been no definitive systematic review and meta-analysis of data to estimate global prevalence of BO or oesophageal adenocarcinoma in individuals with gastro-oesophageal reflux.

DESIGN

We searched MEDLINE, Embase and Embase Classic to identify cross-sectional surveys that reported prevalence of BO or oesophageal adenocarcinoma in adults with gastro-oesophageal reflux. We extracted prevalence for all studies, both for endoscopically suspected and histologically confirmed cases. We calculated pooled prevalence according to study location, symptom frequency and sex, as well as ORs with 95% CIs.

RESULTS

Of the 4963 citations evaluated, 44 reported prevalence of endoscopically suspected and/or histologically confirmed BO. Prevalence of BO among individuals with gastro-oesophageal reflux varied according to different geographical regions ranging from 3% to 14% for histologically confirmed BO with a pooled prevalence of 7.2% (95% CI 5.4% to 9.3%), whereas pooled prevalence for endoscopically suspected BO was 12.0% (95% CI 5.5% to 20.3%). There was heterogeneity in many of our analyses. Prevalence of BO was significantly higher in men, both for endoscopically suspected (OR=2.1; 95% CI 1.6 to 2.8) and histologically confirmed BO (OR=2.3; 95% CI 1.7 to 3.2). Dysplasia was present in 13.9% (95% CI 8.9% to 19.8%) of cases of histologically confirmed BO, 80.7% of which was low-grade.

CONCLUSION

The prevalence of Barrett's oesophagus among individuals with gastro-oesophageal reflux varied strikingly among countries, broadly resembling the geographical distribution of gastro-oesophageal reflux itself. Prevalence of BO was significantly higher in men.

The pharmacotherapeutic management of gastroesophageal reflux disease (GERD)

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a very common worldwide condition, affecting about 15-20% of the whole population, and representing a major burden for health-care systems. Because of its frequency, health physicians - family doctors as well as specialists - should be aware of the different pharmacotherapeutic approaches in managing GERD, according to disease severity.

AREAS COVERED

Authors summarize the pharmacological management of GERD in adults, present the different pharmaceutical classes, and review the evidence on efficacy for each treatment according to the most common clinical scenarios: non-erosive gastroesophageal reflux disease (NERD), erosive esophagitis (EE), and proton-pump inhibitor (PPI) refractory GERD. They also provide an overview of treatments under development.

EXPERT OPINION

To date, PPIs remain the most effective treatment option for both NERD and EE. However, Potassium-Competitive Acid blockers (PCAB) may be considered, with at least similar efficacy in Asian populations. Preliminary data suggest that PCABs could be superior to classic PPIs in patients with severe EE, and may also be of particular interest in the management of PPI-refractory GERD patients. Their definitive role in GERD management, however, still remains to be determined based on properly designed and conducted randomized clinical trials.

Integrated PPI- and WGCNA-Retrieval of Hub Gene Signatures Shared Between Barrett's Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is a deadly cancer with high mortality rate, especially in economically advanced countries, while Barrett's esophagus (BE) is reported to be a precursor that strongly increases the risk of EAC. Due to the complexity of these diseases, their molecular mechanisms have not been revealed clearly. This study aims to explore the gene signatures shared between BE and EAC based on integrated network analysis. We obtained EAC- and BE-associated microarray datasets GSE26886, GSE1420, GSE37200, and GSE37203 from the Gene Expression Omnibus and ArrayExpress using systematic meta-analysis. These data were accompanied by clinical data and RNAseq data from The Cancer Genome Atlas (TCGA). Weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) analysis were conducted to explore the relationship between gene sets and clinical traits as well as to discover the key relationships behind the co-expression modules. A differentially expressed gene-based protein-protein interaction (PPI) complex was used to extract hub genes through Cytoscape plugins. As a result, 403 DEGs were excavated, comprising 236 upregulated and 167 downregulated genes, which are involved in the cell cycle and replication pathways. Forty key genes were identified using modules of MCODE, CytoHubba, and CytoNCA with different algorithms. A dark-gray module with 207 genes was identified which having a high correlation with phenotype (gender) in the WGCNA. Furthermore, five shared hub gene signatures (SHGS), namely, pre-mRNA processing factor 4 (PRPF4), serine and arginine-rich splicing factor 1 (SRSF1), heterogeneous nuclear ribonucleoprotein M (HNRNPM), DExH-Box Helicase 9 (DHX9), and origin recognition complex subunit 2 (ORC2), were identified between BE and EAC. SHGS enrichment denotes that RNA metabolism and splicosomes play a key role in esophageal cancer development and progress. We conclude that the PPI complex and WGCNA co-expression network highlight the importance of phenotypic identifying hub gene signatures for BE and EAC.