Cigarette smoking is a modifiable risk factor for Barrett's oesophagus

Categorizing Risks within Barrett's Esophagus To Guide Surveillance and Interception; Suggesting a New Framework

Barrett's esophagus is a precancerous condition that can progress in a stepwise manner to dysplasia and eventually esophageal adenocarcinoma (EAC). Once diagnosed, patients with Barrett's esophagus are kept on surveillance to detect progression so that timely intervention can occur with endoscopic therapy. Several demographic and clinical risk factors are known to increase progression toward EAC, such as longer Barrett's segments, and these patients are kept on tighter surveillance. While p53 IHC has been advocated as an adjunct to histopathologic diagnosis, use of this biomarker is variable, and no other molecular factors are currently applied. Given the new evidence available, it is time to consider whether other risk factors or tools could be applied in clinical practice to decide on closer or attenuated surveillance. In this commentary, we summarize the most relevant risk factors for Barrett's esophagus progression, highlight the most promising novel risk stratification tools-including nonendoscopic triage and commercial biomarker panels, and propose a new framework suggesting how to incorporate risk stratification into clinical practice.

Cigarette Smoke Enhances the Malignant Phenotype of Esophageal Adenocarcinoma Cells by Disrupting a Repressive Regulatory Interaction Between miR-145 and LOXL2

Although linked to esophageal carcinogenesis, the mechanisms by which cigarette smoke mediates initiation and progression of esophageal adenocarcinomas (EAC) have not been fully elucidated. In this study, immortalized esophageal epithelial cells and EAC cells (EACCs) were cultured with or without cigarette smoke condensate (CSC) under relevant exposure conditions. Endogenous levels of microRNA (miR)-145 and lysyl-likeoxidase 2 (LOXL2) were inversely correlated in EAC lines/tumors compared with that in immortalized cells/normal mucosa. The CSC repressed miR-145 and upregulated LOXL2 in immortalized esophageal epithelial cells and EACCs. Knockdown or constitutive overexpression of miR-145 activated or depleted LOXL2, respectively, which enhanced or reduced proliferation, invasion, and tumorigenicity of EACC, respectively. LOXL2 was identified as a novel target of miR-145 as well as a negative regulator of this miR in EAC lines/Barrett's epithelia. Mechanistically, CSC induced recruitment of SP1 to the LOXL2 promoter; LOXL2 upregulation coincided with LOXL2 enrichment and concomitant reduction of H3K4me3 levels within the promoter of miR143HG (host gene for miR-145). Mithramycin downregulated LOXL2 and restored miR-145 expression in EACC and abrogated LOXL2-mediated repression of miR-145 by CSC. These findings implicate cigarette smoke in the pathogenesis of EAC and demonstrate that oncogenic miR-145-LOXL2 axis dysregulation is potentially druggable for the treatment and possible prevention of these malignancies.

Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus is a metaplastic change of esophageal mucosa, which can be characterized by its salmon-colored lining and the presence of columnar epithelium with goblet cells. It is a well-established precancerous state of esophageal adenocarcinoma, a tumor with very poor survival rates, which incidence is rapidly growing. Despite numerous research, the debate about its diagnosis and management is still ongoing. This article aims to provide an overview of the current recommendations and new discoveries regarding the subject.

Barrett Esophagus: A Review

IMPORTANCE

Barrett esophagus is characterized by the replacement of normal esophageal squamous cell epithelium with columnar metaplasia and affects approximately 5% of people in the US and approximately 1% worldwide. Approximately 3% to 5% of patients with Barrett esophagus will be diagnosed with esophageal adenocarcinoma in their lifetime.

OBSERVATIONS

Barrett esophagus affects approximately 2.3% to 8.3% of people with gastroesophageal reflux disease (GERD) and approximately 1.2% to 5.6% of people without GERD. Characteristics associated with Barrett esophagus include older age (prevalence of approximately 1.1% in individuals older than 50 years compared with 0.3% in those 50 years or younger), male sex, and smoking (prevalence of approximately 12% in people who smoke cigarettes compared with 1.1% in those who do not smoke cigarettes). The histopathology of Barrett esophagus progresses from metaplasia to dysplasia and, without treatment, can progress to adenocarcinoma. People with Barrett esophagus have approximately a 0.2% to 0.5% annual rate of developing esophageal adenocarcinoma. Management of Barrett esophagus primarily consists of acid-suppressive medications to reduce underlying GERD symptoms and surveillance endoscopy every 3 to 5 years. In patients with Barrett esophagus and dysplasia or early cancer, endoscopic therapy consisting of resection and ablation successfully treats 80% to 90% of patients.

CONCLUSIONS AND RELEVANCE

Barrett esophagus affects approximately 5% of people in the US and approximately 1% worldwide and is associated with an increased risk of esophageal adenocarcinoma. First-line therapy for Barrett esophagus consists of proton-pump inhibitors for control of reflux symptoms, but their role in chemoprevention is unclear. Surveillance with upper endoscopy is recommended by practice guidelines to monitor for progression to esophageal adenocarcinoma, but randomized clinical trials are lacking.

Risk factors for Barrett's esophagus: Recent advances

Esophageal adenocarcinoma (EAC) is the most common malignant tumor of the esophagus in the West. During the past few decades, its morbidity has been increasing in China. Barrett's esophagus (BE) is defined as the replacement of normal squamous epithelium in the lower esophagus by metaplasia of columnar epithelium. BE is closely related to the occurrence of EAC. Knowledge regarding the risk factors for the occurrence and development of BE is of great significance for early screening and diagnosis of BE and prevention of EAC. In this paper, we review the clinical, demographics-related, lifestyle-related, and medications-related risk factors for BE to provide more valuable scientific evidence for the prevention and treatment of BE.

Barrett's esophagus: results from an Italian cohort with tight endoscopic surveillance

BACKGROUND AND AIM

Barrett's Esophagus represents a condition that predisposes to the development of esophageal adenocarcinoma. The aim of the present study was to analyze the demographic and clinical characteristics of patients with BE, to establish the presence of risk factors for this condition, and to determine the frequency of dysplastic lesions as well as the evolution towards adenocarcinoma under tight endoscopic control.

METHODS

In this study, we retrospectively collected and analyzed data from a cohort of patients with Barrett's Esophagus identified through endoscopic records of ULSS7 in Northern Italy, who underwent upper esophagogastroduodenoscopy over a 10-year period from July 2008 to December 2020.

RESULTS

A total of 264 patients were identified as having BE and included in the study. Mean follow-up was 6.7 years (range: 3 months-13 years). Demographic characteristics of the study population included mean age of 62.7 years (range 33-90 years), with 62.5% of the study population being aged 60 or older, and a male predominance. Females were significantly older than males (65.7 years, range 37-90 vs 61.9 years, range 33-87, p=0.043, respectively).

CONCLUSIONS

The present study confirms the importance of tight endoscopic control in the management of BE, favoring early detection of BE degeneration towards high-grade dysplasia or adenocarcinoma. In a subset of patients with high-risk factors including male sex, cigarette smoking and heavy alcohol intake, it may be worthwhile to consider endoscopic control over time in order to detect the development of BE.

Lifestyle interventions can reduce the risk of Barrett's esophagus: a systematic review and meta-analysis of 62 studies involving 250,157 participants

Background

Barrett's esophagus (BE) is a well‐established risk factor for esophageal adenocarcinoma. Our objective was to investigate the effectiveness of lifestyle interventions on BE risk.

Methods

We searched PubMed, Embase, and Web of Science up to 30 September 2020. The summary relative risks (RRs) and 95% confidence intervals (CIs) for the highest versus lowest categories of exposure were assessed. Analyses of subgroup, dose–response, sensitivity, and publication bias were conducted.

Results

Sixty‐two studies were included that involved more than 250,157 participants and 22,608 cases. Seven lifestyle factors were investigated: smoking, alcohol, body mass index (BMI), physical activity, sleep time, medication, and diet. We observed statistically significant increased BE risks for smoking (RR = 1.35, 95% CI = 1.16–1.57), alcohol intake (RR = 1.23, 95% CI = 1.13–1.34), body fatness (RR = 1.08, 95% CI = 1.03–1.13), less sleep time (RR = 1.76, 95% CI = 1.24–2.49), and proton pump inhibitors use (RR = 1.64, 95% CI = 1.17–2.29). Reduced risks of BE were found for aspirin (RR = 0.70, 95% CI = 0.58–0.84) and the intake of vitamin C (RR = 0.59, 95% CI = 0.44–0.80), folate (RR = 0.47, 95% CI = 0.31–0.71), and fiber (RR = 0.95, 95% CI = 0.93–0.97). The quality of most included studies was high and the subgroup analysis according to the quality score showed significant results (p < 0.05). There was no publication bias for smoking and alcohol. Although the analysis suggested significant evidence of publication bias for BMI, sensitivity analysis showed that the changes in the recalculated RRs were not significant.

Conclusions

The large meta‐analysis revealed that lifestyle modifications could reduce the risks of BE and, consequently, esophageal adenocarcinoma.

Screening and Prevention of Barrett's Esophagus

Barrett's esophagus (BO) is a risk factor for esophageal adenocarcinoma. However, screening for BO is difficult since it is not yet clear who should be screened and which screening method is cost-effective. Screening methods could be upper endoscopy at the time of the first screening colonoscopy, transnasal endoscopy, esophageal capsule endoscopy, or cytosponge. In order to prevent the development of BO or its neoplastic progression, there are modifiable risk factors like obesity or smoking that can be influenced. In addition, several drugs like proton pump inhibitors, aspirin, nonsteroidal anti-inflammatory drugs and statins have shown promising effects in mostly observational studies. However, data from prospective randomized trials are scarce in order to draw final conclusions.

Development of a risk prediction model for Barrett's esophagus in an Australian population

Esophageal adenocarcinoma has poor 5-year survival rates. Increased survival might be achieved with earlier treatment, but requires earlier identification of the precursor, Barrett's esophagus. Population screening is not cost effective, this may be improved by targeted screening directed at individuals more likely to have Barrett's esophagus. To develop a risk prediction tool for Barrett's esophagus, this study compared individuals with Barrett's esophagus against population controls. Participants completed a questionnaire comprising 35 questions addressing medical history, symptom history, lifestyle factors, anthropomorphic measures, and demographic details. Statistical analysis addressed differences between cases and controls, and entailed initial variable selection, checking of model assumptions, and establishing calibration and discrimination. The area under the curve (AUC) was used to assess overall accuracy. One hundred and twenty individuals with Barrett's esophagus and 235 population controls completed the questionnaire. Significant differences were identified for age, gender, reflux history, family reflux history, history of hypertension, alcoholic drinks per week, and body mass index. These were used to develop a risk prediction model. The AUC was 0.82 (95% CI 0.78-0.87). Good calibration between predicted and observed risk was noted (Hosmer-Lemeshow test P = 0.67). At the point minimizing false positives and false negatives, the model achieved a sensitivity of 84.96% and a specificity of 66%. A well-calibrated risk prediction model with good discrimination has been developed to identify patients with Barrett's esophagus. The model needs to be externally validated before consideration for clinical practice.

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.

Reduced Risk of Barrett's Esophagus in Statin Users: Case-Control Study and Meta-Analysis

BACKGROUND

Use of statins has been associated with a reduced incidence of esophageal adenocarcinoma in population-based studies. However there are few studies examining statin use and the development of Barrett's esophagus.

AIM

The purpose of this study was to examine the association between statin use and the presence of Barrett's esophagus in patients having their first gastroscopy.

METHODS

We have performed a case-control study comparing statin use between patients with, and without, an incident diagnosis of non-dysplastic Barrett's esophagus. Male Barrett's cases (134) were compared to 268 male age-matched controls in each of two control groups (erosive gastro-esophageal reflux and dyspepsia without significant upper gastrointestinal disease). Risk factor and drug exposure were established using standardised interviews. Logistic regression was used to compare statin exposure and correct for confounding factors. We performed a meta-analysis pooling our results with three other case-control studies.

RESULTS

Regular statin use was associated with a significantly lower incidence of Barrett's esophagus compared to the combined control groups [adjusted OR 0.62 (95 % confidence intervals 0.37-0.93)]. This effect was more marked in combined statin plus aspirin users [adjusted OR 0.43 (95 % CI 0.21-0.89)]. The inverse association between statin or statin plus aspirin use and risk of Barrett's was significantly greater with longer duration of use. Meta-analysis of pooled data (1098 Barrett's, 2085 controls) showed that statin use was significantly associated with a reduced risk of Barrett's esophagus [pooled adjusted OR 0.63 (95 % CI 0.51-0.77)].

CONCLUSIONS

Statin use is associated with a reduced incidence of a new diagnosis of Barrett's esophagus.

Pathophysiological mechanisms linking obesity and esophageal adenocarcinoma

In recent decades there has been a dramatic rise in the incidence of esophageal adenocarcinoma (EAC) in the developed world. Over approximately the same period there has also been an increase in the prevalence of obesity. Obesity, especially visceral obesity, is an important independent risk factor for the development of gastro-esophageal reflux disease, Barrett’s esophagus and EAC. Although the simplest explanation is that this mediated by the mechanical effects of abdominal obesity promoting gastro-esophageal reflux, the epidemiological data suggest that the EAC-promoting effects are independent of reflux. Several, not mutually exclusive, mechanisms have been implicated, which may have different effects at various points along the reflux-Barrett’s-cancer pathway. These mechanisms include a reduction in the prevalence of Helicobacter pylori infection enhancing gastric acidity and possibly appetite by increasing gastric ghrelin secretion, induction of both low-grade systemic inflammation by factors secreted by adipose tissue and the metabolic syndrome with insulin-resistance. Obesity is associated with enhanced secretion of leptin and decreased secretion of adiponectin from adipose tissue and both increased leptin and decreased adiponectin have been shown to be independent risk factors for progression to EAC. Leptin and adiponectin have a set of mutually antagonistic actions on Barrett’s cells which appear to influence the progression of malignant behaviour. At present no drugs are of proven benefit to prevent obesity associated EAC. Roux-en-Y reconstruction is the preferred bariatric surgical option for weight loss in patients with reflux. Statins and aspirin may have chemopreventative effects and are indicated for their circulatory benefits.