Mechanisms and pathophysiology of Barrett oesophagus

Multi-omic profiling identifies KRT1 as a predictor of immune infiltration and prognosis in gastroesophageal junction cancer

Gastroesophageal junction cancer (GEJ) is typically investigated alongside gastric or esophageal cancers. However, separate molecular profiles and immune cell infiltration of GEJ remain largely unknown. This study screened for hub genes in GEJ, studied their function and regulation in biological processes, and investigated their relationship with the infiltration of immune cells into tumors. Datasets were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus public databases. Molecular profiling revealed significant down-regulated expression of key genes in GEJ and enrichment in pathways related to epithelial cell differentiation and development, and structural constituents of skin epidermis. Prognostic analysis showed that patients with low KRT1, Desmocollin 2, and Envoplakin expression had a worse prognosis. There was a strong correlation between the levels of KRT1 and both the tumor mutational burden and immune cell infiltration. Single gene pathway enrichment analysis and in vitro experiments confirmed that cancer cell proliferation, migration, and invasion were suppressed by KRT1 via the AKT/mTOR pathway. In conclusion, this multi-dimensional study analyzed the molecular alterations and oncological mechanisms underlying the progression of GEJ. KRT1 is a promising candidate biomarker for the molecular and immunological characterization of GEJ and for prognosis prediction.

High Risk of Persistence and Risk of Dysplasia After Diagnosis of Ultrashort Barrett's Esophagus

INTRODUCTION

The management of ultrashort (<1 cm) Barrett's esophagus (BE) remains unclear. We aimed to determine the prevalence of ultrashort BE (USBE) at index diagnosis, identify factors associated with persistent BE after USBE diagnosis, and identify risk of dysplasia after initial USBE in a population of US veterans.

METHODS

This was a retrospective cohort study at the Veterans Affairs hospital in Houston, TX, of consecutive patients with new BE diagnosis from November 1990 to June 2022 with follow-up through April 2023. Using a pathology database, we identified patients with a new USBE diagnosis and any subsequent follow-up esophagogastroduodenoscopy (EGD). We examined the association of sociodemographic and clinical risk factors of persistent USBE cohort compared with longer-length segment BE and those with a negative follow-up EGD after index USBE with χ 2 tests and logistic regression models. Last, we calculated the prevalence and incidence of any dysplasia in persistent BE after USBE at index diagnosis compared with BE ≥1 cm. We excluded patients without at least 1 follow-up endoscopy.

RESULTS

Of 739 patients with BE, 167 (22.6%) had USBE on index EGD. Of those with index USBE, 86 (51.5%) had persistent BE and 67 (40.1%) had negative intestinal metaplasia on follow-up EGD. There was a greater proportion of non-Hispanic White and Hispanic than non-Hispanic Black patients with persistent BE after index USBE and the negative follow-up of EGD cohorts ( P = 0.012), but no significant difference in age, sex, smoking status, alcohol status, and body mass index between the 2 groups. White race (adjusted odds ratio [aOR] 3.80; 95% confidence interval [CI] 1.35-10.7) and Hispanic ethnicity (aOR 4.85; 95% CI 1.19-19.7; ref: non-Hispanic Black) were associated with an increased likelihood of persistent BE. During 3,880.7 person-years of follow-up, 112 patients (10 persistent BE after index USBE) developed definite dysplasia/neoplasia. The incidence rate of definite dysplasia/neoplasia was 19.5 per 1,000 person-years (95% CI 10.5-36.3 per 1,000 person-years) in those with persistent BE after USBE and 33.8 per 1,000 person-years (95% CI 27.9-41.1 per 1,000 person-years) in those with longer segment BE ( P value by log-rank test = 0.23; hazard ratio 0.67; 95% CI 0.35-1.29). We did not identify any significant predictors of dysplasia in persistent BE after index endoscopy with USBE.

DISCUSSION

The prevalence of persistent BE after index USBE is high, and there is a risk of developing dysplasia/neoplasia in persistent BE after USBE. We were unable to detect a difference in the risk of dysplasia/neoplasia between persistent BE after index USBE and BE ≥1 cm on index endoscopy in a cohort of US veterans. White race and Hispanic ethnicity are associated with persistent BE after index USBE and may be target demographics for surveillance.

Effect of Aspirin on Biomarkers of Barrett's Esophagus After Successful Eradication with Radiofrequency Ablation

OBJECTIVES/METHODS

Placebo-controlled phase II study evaluated aspirin's effect on CDX2 mRNA and prostanoid production in native and neosquamous epithelium after successful radiofrequency ablation (RFA) in Barrett's esophagus.

RESULTS

At 12 months TXB2, PGF2α, PGD2, PGE2, PGE1, and α13PGE2 increased in native squamous but not neosquamous epithelium in individuals randomized to placebo. Aspirin use significantly reduced CDX2 mRNA in native squamous epithelium, and was associated with decreases in PGE1, PGE2 and 13PGE2 in neosquamous epithelium.

CONCLUSIONS

After RFA, native squamous and neosquamous epithelium exhibit different molecular markers and responses to aspirin suggesting that different sources of squamous progenitors contribute to esophageal re-epithelization.

Altered Microbiome Promotes Pro-Inflammatory Pathways in Oesophago-Gastric Tumourigenesis

INTRODUCTION

The upper gastrointestinal microbiome is a dynamic entity that is involved in numerous processes including digestion, production of vitamins and protection against pathogens. Many external and intrinsic factors may cause changes in the proportions of bacteria within the microbial community, termed 'dysbiosis'. A number of these have been identified as risk factors for a range of diseases, including oesophago-gastric carcinoma.

MATERIALS AND METHODS

A narrative review was conducted to elucidate the current evidence on the role of the microbiome in promoting oesophago-gastric tumourigenesis. Significant causes of dysbiosis including age, medications and GORD were examined and key pro-inflammatory pathways implicated in tumourigenesis and their interaction with the microbiome were described.

RESULTS AND DISCUSSION

An association between microbial dysbiosis and development of oesophago-gastric cancer may be mediated via activation of pro-inflammatory pathways, the inflammasome and the innate immune system. Advances in sequencing technology allow microbial communities to be fingerprinted by sequencing the 16S rRNA gene, enabling a deeper understanding of the genera that may be implicated in driving tumourigenesis.

CONCLUSIONS

Developing a greater understanding of the influence of the microbiota on oesophago-gastric tumourigenesis may enable advances to be made in the early detection of malignancy and in the development of novel systemic therapies, leading to improved rates of survival.

Etiologic factors for Barrett's esophagus: toward countermeasures in Asia

INTRODUCTION

Over the past several decades, Europe and the United States have experienced a rapid increase in esophageal adenocarcinoma. Research and countermeasures against Barrett's esophagus, its precancerous lesion, are progressing. Because esophageal adenocarcinoma has an extremely poor prognosis when diagnosed in an advanced stage, recommendations for early cancer detection have been made based on the various proven etiological factors of Barrett's esophagus and the actual cancer risk of Barrett's esophagus. In recent years, there have been indications of an increase in esophageal adenocarcinoma in Japan, and a similar trend of cancer will occur shortly in other Asian countries. Consequently, Asian countries must implement similar countermeasures against Barrett's esophagus and esophageal adenocarcinoma, referencing the knowledge gained thus far in Europe and the United States.

AREAS COVERED

This review summarizes the latest findings on the etiologic factors of Barrett's esophagus and discusses the differences between Westerners and Asians. The current status of Barrett's esophagus in Japan and other Asian countries is also summarized.

EXPERT OPINION

The etiological factors and cancer incidence of Barrett's esophagus in Asia diverge somewhat from those observed in Europe and America. Therefore, it is imperative to implement measures that are tailored to the actual circumstances of Asian people.

Gastrointestinal Cancer Precursor Conditions and Their Detection

Gastrointestinal cancers are a leading cause of cancer morbidity and mortality. Many gastrointestinal cancers develop from cancer precursor lesions, which are commonly found in individuals with hereditary cancer syndromes. Hereditary cancer syndromes have advanced our understanding of cancer development and progression and have facilitated the evaluation of cancer prevention and interception efforts. Common gastrointestinal hereditary cancer syndromes, including their organ-specific cancer risk and surveillance recommendations, are reviewed in this article. The management of common gastroesophageal, pancreatic, and colonic precursor lesions is also discussed, regardless of their genetic background. Further research is needed to advance chemoprevention and immunoprevention strategies.

System transferability of Raman-based oesophageal tissue classification using modern machine learning to support multi-centre clinical diagnostics

BACKGROUND

The clinical potential of Raman spectroscopy is well established but has yet to become established in routine oncology workflows. One barrier slowing clinical adoption is a lack of evidence demonstrating that data taken on one spectrometer transfers across to data taken on another spectrometer to provide consistent diagnoses.

METHODS

We investigated multi-centre transferability using human oesophageal tissue. Raman spectra were taken across three different centres with different spectrometers of the same make and model. By using a common protocol, we aimed to minimise the difference in machine learning performance between centres.

RESULTS

61 oesophageal samples from 51 patients were interrogated by Raman spectroscopy at each centre and classified into one of five pathologies. The overall accuracy and log-loss did not significantly vary when a model trained upon data from any one centre was applied to data taken at the other centres. Computational methods to correct for the data during pre-processing were not needed.

CONCLUSION

We have found that when using the same make and model of spectrometer, together with a common protocol, across different centres it is possible to achieve system transferability without the need for additional computational instrument correction.

The role of the fibroblast in Barrett's esophagus and esophageal adenocarcinoma

PURPOSE OF REVIEW

Barrett's esophagus (BE) is the number one risk factor for developing esophageal adenocarcinoma (EAC), a deadly cancer with limited treatment options that has been increasing in incidence in the US. In this report, we discuss current studies on the role of mesenchyme and cancer-associated fibroblasts (CAFs) in BE and EAC, and we highlight translational prospects of targeting these cells.

RECENT FINDINGS

New insights through studies using single-cell RNA sequencing (sc-RNA seq) have revealed an important emerging role of the mesenchyme in developmental signaling and cancer initiation. BE and EAC share similar stromal gene expression, as functional classifications of nonepithelial cells in BE show a remarkable similarity to EAC CAFs. Several recent sc-RNA seq studies and novel organoid fibroblast co-culture systems have characterized the subgroups of fibroblasts in BE and EAC, and have shown that these cells can directly influence the epithelium to induce BE development and cancer progression. Targeting the CAFs in EAC with may be a promising novel therapeutic strategy.

SUMMARY

The fibroblasts in the surrounding mesenchyme may have a direct role in influencing altered epithelial plasticity during BE development and progression to EAC.

Decoding spatiotemporal transcriptional dynamics and epithelial fibroblast crosstalk during gastroesophageal junction development through single cell analysis

The gastroesophageal squamocolumnar junction (GE-SCJ) is a critical tissue interface between the esophagus and stomach, with significant relevance in the pathophysiology of gastrointestinal diseases. Despite this, the molecular mechanisms underlying GE-SCJ development remain unclear. Using single-cell transcriptomics, organoids, and spatial analysis, we examine the cellular heterogeneity and spatiotemporal dynamics of GE-SCJ development from embryonic to adult mice. We identify distinct transcriptional states and signaling pathways in the epithelial and mesenchymal compartments of the esophagus and stomach during development. Fibroblast-epithelial interactions are mediated by various signaling pathways, including WNT, BMP, TGF-β, FGF, EGF, and PDGF. Our results suggest that fibroblasts predominantly send FGF and TGF-β signals to the epithelia, while epithelial cells mainly send PDGF and EGF signals to fibroblasts. We observe differences in the ligands and receptors involved in cell-cell communication between the esophagus and stomach. Our findings provide insights into the molecular mechanisms underlying GE-SCJ development and fibroblast-epithelial crosstalk involved, paving the way to elucidate mechanisms during adaptive metaplasia development and carcinogenesis.

Pathophysiology of gastro-oesophageal reflux disease: implications for diagnosis and management

Gastro-oesophageal reflux disease (GERD) is a common gastrointestinal disorder in which retrograde flow of gastric content into the oesophagus causes uncomfortable symptoms and/or complications. It has a multifactorial and partially understood pathophysiology. GERD starts in the stomach, where the refluxate material is produced. Following the trajectory of reflux, the failure of the antireflux barrier, primarily the lower oesophageal sphincter and the crural diaphragm, enables the refluxate to reach the oesophageal lumen, triggering oesophageal or extra-oesophageal symptoms. Reflux clearance mechanisms such as primary and secondary peristalsis and the arrival of bicarbonate-rich saliva are critical to prevent mucosal damage. Alterations of the oesophageal mucosal integrity, such as macroscopic oesophagitis or microscopic changes, determine the perception of symptoms. The intensity of the symptoms is affected by peripheral and central neural and psychological mechanisms. In this Review, we describe an updated understanding of the complex and multifactorial pathophysiology of GERD. It is now recognized that different GERD phenotypes have different degrees of reflux, severity of mucosal integrity damage and type, and severity of symptoms. These variations are probably due to the occurrence of a predominant pathophysiological mechanism in each patient. We also describe the main pathophysiological mechanisms of GERD and their implications for personalized diagnosis and management.

Causal relationships between dietary habits and Barrett's esophagus risk: a univariable and multivariable Mendelian randomization study

Aims: Dietary habits are reported to be associated with Barrett's esophagus (BE) risk; however, whether there is a causal relationship remains controversial. Here, we systematically examined the causal effects of genetically predicted dietary habits on BE risk through a Mendelian randomization (MR) analysis approach. Methods: Data for exposures were obtained from the UK Biobank (UKB), while the summary-level data for outcomes were obtained from a large sample-size GWAS meta-analysis. Genetic variants associated with 17 ordinary dietary habits at the genome-wide significance level were regarded as instrumental variables (IVs). Univariable and multivariable MR analyses were conducted to explore the causal relationships between dietary habits and BE risk. Sensitivity analyses were implemented to evaluate robustness of the results and determine the potential pleiotropy bias. Results: Univariable MR (UVMR) analysis showed that genetic predisposition to alcohol intake frequency, cooked vegetable intake, beef intake, bread intake, fresh fruit intake, salad/raw vegetable intake, and dried fruit intake were associated with BE risk, with all P values <0.05. After adjusting confounders, the effects of four dietary habits on BE risk persisted; multivariable MR (MVMR) analysis revealed that alcohol intake frequency (adjusted odds ratio (OR) = 1.74 (1.34, 2.27); P = 3.42 × 10-5) was causally associated with higher BE risk, the cooked vegetable intake (adjusted OR = 2.64 (1.16, 5.97); P = 0.02) had suggestively increased BE risk, while higher consumption of bread (adjusted OR = 0.54 (0.32-0.91); P = 0.02) and fresh fruit (adjusted OR = 0.34 (0.15, 0.77); P = 0.01) were suggestively associated with lower BE risk. Conclusions: These MR analyses demonstrate evidence of causal relationships between dietary habits and BE risk. These findings provide new insights into targeted dietary intervention strategies for BE prevention.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

Association between hiatal hernia and Barrett's esophagus: an updated meta-analysis with trial sequential analysis

BACKGROUND

Barrett's esophagus (BE) is a precursor of esophageal adenocarcinoma. It is critical to recognize the risk factors associated with BE.

OBJECTIVES

The present meta-analysis aims to systematically estimate the association of hiatal hernia with the risk of BE.

DESIGN

A meta-analysis with trial sequential analysis.

DATA SOURCES AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched. The pooled odds ratios (ORs) and adjusted ORs (aORs) with their 95% confidence intervals (CIs) were calculated for the combined estimation of unadjusted data and data adjusted for confounders, respectively. Heterogeneity was quantified using the Cochrane Q test and I² statistics. Subgroup, meta-regression, and leave-one-out sensitivity analyses were employed to explore the sources of heterogeneity.

RESULTS

Forty-seven studies with 131,517 participants were included. Based on the unadjusted data from 47 studies, hiatal hernia was significantly associated with an increased risk of any length BE (OR = 3.91, 95% CI = 3.31-4.62, p < 0.001). The heterogeneity was significant (I² = 77%; p < 0.001) and the definition of controls (p = 0.014) might be a potential contributor to heterogeneity. Based on the adjusted data from 14 studies, this positive association remained (aOR = 3.26, 95% CI = 2.44-4.35, p < 0.001). The heterogeneity was also significant (I² = 65%; p < 0.001). Meta-analysis of seven studies demonstrated that hiatal hernia was significantly associated with an increased risk of long-segment BE (LSBE) (OR = 10.01, 95% CI = 4.16-24.06, p < 0.001). The heterogeneity was significant (I² = 78%; p < 0.001). Meta-analysis of seven studies also demonstrated that hiatal hernia was significantly associated with an increased risk of short-segment BE (OR = 2.76, 95% CI = 2.05-3.71, p < 0.001). The heterogeneity was not significant (I² = 30%; p = 0.201).

CONCLUSION

Hiatal hernia should be a significant risk factor for BE, especially LSBE.

REGISTRATION

PROSPERO registration number CRD42022367376.

Be like water, my cells: cell plasticity and the art of transformation

Cellular plasticity defines the capacity of cells to adopt distinct identities during development, tissue homeostasis and regeneration. Dynamic fluctuations between different states, within or across lineages, are regulated by changes in chromatin accessibility and in gene expression. When deregulated, cellular plasticity can contribute to cancer initiation and progression. Cancer cells are remarkably plastic which contributes to phenotypic and functional heterogeneity within tumours as well as resistance to targeted therapies. It is for these reasons that the scientific community has become increasingly interested in understanding the molecular mechanisms governing cancer cell plasticity. The purpose of this mini-review is to discuss different examples of cellular plasticity associated with metaplasia and epithelial-mesenchymal transition with a focus on therapy resistance.

Functional Food in Relation to Gastroesophageal Reflux Disease (GERD)

Gastroesophageal reflux disease (GERD) is a common esophageal disorder characterized by troublesome symptoms associated with increased esophageal acid exposure. The cornerstones of therapy in this regard include treatment with acid-suppressive agents, lifestyle modifications, and dietary therapy, although the latter has not been well defined. As concerns regarding long-term proton pump inhibitor (PPI) use continue to be explored, patients and healthcare providers are becoming increasingly interested in the role of diet in disease management. However, dietary interventions lack evidence of the synthesis effect of functional foods. The following is a review of dietary therapy for GERD, emphasizing food components' impact on GERD pathophysiology and management. Although the sequential dietary elimination of food groups is a common practice, the literature supports broader intervention, including reduced overall sugar intake, increased dietary fiber, and changes in overall eating practices. While the primary concern of food companies is to provide safe products, the caloric, nutritional, and functional composition of foods is also generating interest in the food industry due to consumers' concerns.

Shared features of metaplasia and the development of adenocarcinoma in the stomach and esophagus

Introduction: Plasticity is an inherent property of the normal gastrointestinal tract allowing for appropriate response to injury and healing. However, the aberrancy of adaptable responses is also beginning to be recognized as a driver during cancer development and progression. Gastric and esophageal malignancies remain leading causes of cancer-related death globally as there are limited early disease diagnostic tools and paucity of new effective treatments. Gastric and esophageal adenocarcinomas share intestinal metaplasia as a key precancerous precursor lesion.

Methods: Here, we utilize an upper GI tract patient-derived tissue microarray that encompasses the sequential development of cancer from normal tissues to illustrate the expression of a set of metaplastic markers.

Results: We report that in contrast to gastric intestinal metaplasia, which has traits of both incomplete and complete intestinal metaplasia, Barrett's esophagus (i.e., esophageal intestinal metaplasia) demonstrates hallmarks of incomplete intestinal metaplasia. Specifically, this prevalent incomplete intestinal metaplasia seen in Barrett's esophagus manifests as concurrent development and expression of both gastric and intestinal traits. Additionally, many gastric and esophageal cancers display a loss of or a decrease in these characteristic differentiated cell properties, demonstrating the plasticity of molecular pathways associated with the development of these cancers.

Discussion: Further understanding of the commonalities and differences governing the development of upper GI tract intestinal metaplasias and their progression to cancer will lead to improved diagnostic and therapeutic avenues.

P53 Deficiency Accelerate Esophageal Epithelium Intestinal Metaplasia Malignancy

Barrett's esophagus (BE) is a precancerous lesion of esophageal adenocarcinoma (EAC). It is a pathological change in which the squamous epithelium distal esophagus is replaced by columnar epithelium. Loss of P53 is involved in the development of BE and is taken as a risk factor for the progression. We established a HET1A cell line with P53 stably knockdown by adenovirus vector infection, followed by 30 days of successive acidic bile salt treatment. MTT, transwell assay, and wound closure assay were applied to assess cell proliferation and migration ability. The expression of key factors was analyzed by RT-qPCR, western blotting and immunohistochemical staining. Our data show that the protein expression level of P53 reduced after exposure to acidic bile salt treatment, and the P53 deficiency favors the survival of esophageal epithelial cells to accommodate the stimulation of acidic bile salts. Furthermore, exposure to acidic bile salt decreases cell adhesions by repressing the JAK/STAT signaling pathway and activating VEGFR/AKT in P53-deficient esophageal cells. In EAC clinical samples, P53 protein expression is positively correlated with that of ICAM1 and STAT3 and negatively correlated with VEGFR protein expression levels. These findings elucidate the role of P53 in the formation of BE, explain the mechanism of P53 deficiency as a higher risk of progression for BE formation, and provide potential therapeutic targets for EAC.

Surveillance Endoscopy After Foregut Surgery: Is It Necessary?

Patients undergoing foregut surgeries can have de novo findings or worsening of underlying upper gastrointestinal pathologies including Barrett’s esophagus and gastric intestinal metaplasia. These changes carry a potentially increased risk for malignancy development in the future raising the question of the utility of post-operative surveillance endoscopy after esophagectomy, bariatric and metabolic surgeries (Sleeve gastrectomy and Roux-en-Y Gastric Bypass), achalasia treatment, and anti-reflux surgery. In this narrative review, we conduct a literature exploration of available data on post-operative endoscopic surveillance findings following the procedures summarizing the prevalence of upper gastrointestinal pathologies and recommendations on the utility of postoperative endoscopy from established medical societies.