Current and past smoking significantly increase risk for Barrett's esophagus

Risk Factors for the Development of Barrett's Esophagus and Esophageal Adenocarcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Barrett's esophagus (BE) is the most widely established precursor to esophageal adenocarcinoma (EAC). Despite current screening guidelines, more than 90% of EAC patients lack a previous diagnosis of BE. We performed a systematic review and meta-analysis to identify the most important risk factors for the development of BE or EAC.

RECENT FINDINGS

PubMed.gov, Ovid Medline, Embase, and Cochrane Library were searched through March 15, 2024. Studies comparing characteristics of patients with endoscopically diagnosed BE or EAC to control groups satisfied our inclusion criteria. Dual extraction provided data for random-effects meta-analyses. Sufficient data were extracted from 54 included studies to perform our meta-analyses. There were five risk factors with significant associations for the development of BE: symptoms of gastroesophageal reflux at least once weekly (OR, 3.56; 95% confidence interval [CI], 2.03-6.25; p = 0.004) tobacco smoking (OR, 1.41; 95% CI, 1.30-1.51; p < 0.001); alcohol use (OR, 1.37; 95% CI, 1.10-1.71; p = 0.008); male gender (OR, 1.36; 95% CI, 1.19-1.57; p < 0.001); and obesity (BMI > 30 kg/m2) (OR, 1.23; 95% CI, 1.09-1.39; p = 0.003). Tobacco smoking was significantly associated with the diagnosis of EAC (OR, 2.15; 95% CI, 1.85-2.43; p < 0.001).

CONCLUSION

Five risk factors showed significant associations with the development of BE and one with the development of EAC, with over a three-fold increase in BE for patients with gastroesophageal reflux more than once weekly. These data could prove useful in developing diagnostic paradigms with higher emphasis on patients experiencing more frequent acid reflux.

Obesity is associated with higher prevalence of gastroesophageal reflux disease and reflux related complications: A global healthcare database study

BACKGROUND

Prior studies have demonstrated that obesity may be associated with the development of gastroesophageal reflux disease (GERD) and GERD-related complications. However, such association has never been assessed in a global-wide real-world patient population.

METHODS

The TriNetX electronic health records network, which involves 92 healthcare organizations in 12 countries, was utilized for this multicenter global health research network study. The cohort with obesity comprised adult patients with body mass index (BMI) of more than 30 kg/m2. We performed 1:1 propensity score matching to decrease confounders effects. The prevalence of GERD and GERD-related complications including erosive esophagitis, Barrett's esophagus (BE), BE with dysplasia, and esophageal adenocarcinoma were assessed.

RESULTS

A total of 2,356,548 patients were included in the obesity and non-obesity groups after propensity score matching. In the group with obesity, patients had a significantly higher prevalence of GERD (30% vs. 24%, OR 1.35, 95% CI 1.34-1.36) compared to the group without obesity. Further analysis showed a higher prevalence of GERD-related complications in the group with obesity with statistical significance: Erosive esophagitis (OR 1.07, 95% CI 1.05-1.08), Barrett's esophagus (1.08, 1.05-1.10), BE with dysplasia (1.11, 1.04-1.18), esophageal cancer (1.32, 1.15-1.51).

CONCLUSION

Globally, obesity was associated with a higher prevalence of GERD and GERD-related complications.

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.

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.

Global burden and epidemiology of Barrett oesophagus and oesophageal cancer

Oesophageal cancer is a global health problem; in 2018 there were more than 572,000 people newly diagnosed with oesophageal cancer worldwide. There are two main histological subtypes of oesophageal cancer, oesophageal adenocarcinoma (EAC) and oesophageal squamous cell carcinoma (ESCC), and there has been a dramatic shift in its epidemiology. While the incidence of EAC and its precursor lesion, Barrett oesophagus, has increased in Western populations over the past four decades, the incidence of ESCC has declined in most parts of the world over the same period. ESCC still accounts for the vast majority of all oesophageal cancer cases diagnosed worldwide each year. Prognosis for patients with oesophageal cancer is strongly related to stage at diagnosis. As most patients are diagnosed with late-stage disease, overall 5-year survival for oesophageal cancer remains <20%. Knowledge of epidemiology and risk factors for oesophageal cancer is essential for public health and clinical decisions about risk stratification, screening and prevention. The goal of this Review is to establish the current epidemiology of oesophageal cancer, with a particular focus on the Western world and the increasing incidence of EAC and Barrett oesophagus.

Diabetes in relation to Barrett's esophagus and adenocarcinomas of the esophagus: A pooled study from the International Barrett's and Esophageal Adenocarcinoma Consortium

BACKGROUND

Diabetes is positively associated with various cancers, but its relationship with tumors of the esophagus/esophagogastric junction remains unclear.

METHODS

Data were harmonized across 13 studies in the International Barrett's and Esophageal Adenocarcinoma Consortium, comprising 2309 esophageal adenocarcinoma (EA) cases, 1938 esophagogastric junction adenocarcinoma (EGJA) cases, 1728 Barrett's esophagus (BE) cases, and 16,354 controls. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% CIs for self-reported diabetes in association with EA, EGJA, and BE. Adjusted ORs were then combined using random-effects meta-analysis.

RESULTS

Diabetes was associated with a 34% increased risk of EA (OR, 1.34; 95% CI, 1.00-1.80; I2  = 48.8% [where 0% indicates no heterogeneity, and larger values indicate increasing heterogeneity between studies]), 27% for EGJA (OR, 1.27; 95% CI, 1.05-1.55; I2  = 0.0%), and 30% for EA/EGJA combined (OR, 1.30; 95% CI, 1.06-1.58; I2  = 34.9%). Regurgitation symptoms modified the diabetes-EA/EGJA association (P for interaction = .04) with a 63% increased risk among participants with regurgitation (OR, 1.63; 95% CI, 1.19-2.22), but not among those without regurgitation (OR, 1.03; 95% CI, 0.74-1.43). No consistent association was found between diabetes and BE.

CONCLUSIONS

Diabetes was associated with increased EA and EGJA risk, which was confined to individuals with regurgitation symptoms. Lack of an association between diabetes and BE suggests that diabetes may influence progression of BE to cancer.

Use of the Electronic Health Record to Target Patients for Non-endoscopic Barrett's Esophagus Screening

BACKGROUND

Clinical prediction models targeting patients for Barrett's esophagus (BE) screening include data obtained by interview, questionnaire, and body measurements. A tool based on electronic health records (EHR) data could reduce cost and enhance usability, particularly if combined with non-endoscopic BE screening methods.

AIMS

To determine whether EHR-based data can identify BE patients.

METHODS

We performed a retrospective review of patients ages 50-75 who underwent a first-time esophagogastroduodenoscopy. Data extracted from the EHR included demographics and BE risk factors. Endoscopy and pathology reports were reviewed for histologically confirmed BE. Screening criteria modified from clinical guidelines were assessed for association with BE. Subsequently, a score based on multivariate logistic regression was developed and assessed for its ability to identify BE subjects.

RESULTS

A total of 2931 patients were assessed, and BE was found in 1.9%. Subjects who met screening criteria were more likely to have BE (3.3% vs. 1.1%, p = 0.001), and the criteria predicted BE with an AUROC of 0.65 (95% CI 0.59-0.71). A score based on logistic regression modeling included gastroesophageal reflux disease, sex, body mass index, and ever-smoker status and identified BE subjects with an AUROC of 0.71 (95% CI 0.64-0.77). Both prediction tools produced higher AUROCs in women than in men.

CONCLUSIONS

EHR-based BE risk prediction tools identify BE patients with fair accuracy. While these tools may improve the efficiency of patient targeting for BE screening in the primary care setting, challenges remain to identify high-risk patients for non-invasive BE screening in clinical practice.

Risk factors for Barrett's esophagus in young adults who underwent upper gastrointestinal endoscopy in a health examination center

BACKGROUND

Barrett's esophagus (BE) is a premalignant condition with increased incidence worldwide both in old and young individuals. However, the role of certain potential risk factors remains unclear in young adults (< 50 years). We aimed to determine the risk factors of BE in young adults.

METHODS

A total of 4943 young adults who underwent upper gastrointestinal endoscopy at our health check-up center were enrolled. The diagnosis of BE was based on histological confirmation. We analyzed demographic factors, laboratory data, potential risk factors such as smoking, alcohol consumption, presence of gastroesophageal reflux disease (GERD) symptoms, and metabolic syndrome for the risk of BE by using binary logistic regression analysis.

RESULTS

The prevalence of BE was 1.8% (88/4943). Male sex, the presence of GERD symptoms, and smoking were three significant risk factors related to BE. Furthermore, participants who had smoked for 10 pack-years or more had increased risk of BE with dose-dependent phenomenon (p trend < 0.001). The proportion of BE in male participants with both GERD symptoms and a smoking history of 10 pack-years or more was as high as 10.3% (16/155).

CONCLUSIONS

Significant risk factors of BE in young adults are male sex, the presence of GERD symptoms, and smoking. The risk also increases with an increase in cumulative exposure to smoking.

Barrett's Esophagus and Esophageal Adenocarcinoma: How Common Are They Really?

Since the early 1970s, the incidence of esophageal adenocarcinoma (EA) has increased dramatically in most Western populations while the incidence of esophageal squamous cell carcinoma has decreased. As a result, EA has become the predominant subtype of esophageal cancer in North America and Europe and is an important contributor to overall cancer mortality. Barrett's esophagus (BE), a metaplastic columnar epithelium of the distal esophagus, is the known precursor lesion for EA. EA and BE occur more frequently in white men over 50 years old, as well as in people with frequent symptoms of gastroesophageal reflux, in smokers, and in people who are obese. Conversely, EA and BE are less common in persons using nonsteroidal anti-inflammatory drugs and in person with Helicobacter pylori infection. The 5-year survival rate for patients with EA, although generally poor, has improved during the past decade, and long-term survival is increasingly possible for patients with early or locally advanced disease. This review combines a synthesis of published studies with an analysis of data from the United States National Cancer Institute's Surveillance, Epidemiology, and End Results program to discuss the change in incidence of EA and summarize current knowledge of risk factors.

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

BACKGROUND

Esophageal adenocarcinoma is a disease that has a high mortality rate, the only known precursor being Barrett's esophagus (BE). While screening for BE is not cost-effective at the population level, targeted screening might be beneficial. We have developed a risk prediction model to identify people with BE, and here we present the external validation of this model.

MATERIALS AND METHODS

A cohort study was undertaken to validate a risk prediction model for BE. Individuals with endoscopy and histopathology proven BE completed a questionnaire containing variables previously identified as risk factors for this condition. Their responses were combined with data from a population sample for analysis. Risk scores were derived for each participant. Overall performance of the risk prediction model in terms of calibration and discrimination was assessed.

RESULTS

Scores from 95 individuals with BE and 636 individuals from the general population were analyzed. The Brier score was 0.118, suggesting reasonable overall performance. The area under the receiver operating characteristic was 0.83 (95% CI 0.78-0.87). The Hosmer-Lemeshow statistic was p=0.14. Minimizing false positives and false negatives, the model achieved a sensitivity of 74% and a specificity of 73%.

CONCLUSION

This study has validated a risk prediction model for BE that has a higher sensitivity than previous models.

Alcohol, smoking and risk of oesophago-gastric cancer

Oesophago-gastric cancers (oesophageal and gastric cancers) are common, highly fatal cancers. Oesophageal squamous cell carcinoma (OSCC) and oesophageal adenocarcinoma (OAC) are the two main histological subtypes of oesophageal cancer. Globally, OSCC remains the most common histological subtype of oesophageal cancer, with the highest burden occurring along two geographic belts, one from north central China through the central Asian republics to northern Iran, and one from eastern to southern Africa. In Western countries, the incidence of OAC has increased dramatically over the past 40 years. OAC is now the most common subtype of oesophageal cancer in the United States, United Kingdom, and Australia. Approximately 90% of gastric cancers are adenocarcinoma, with the majority of cases diagnosed in Eastern Asia, Eastern Europe, and some Latin American countries. Smoking is an established risk factor for both oesophageal (OSCC and OAC) and gastric cancers. Alcohol consumption, however, is strongly associated with increased risk of OSCC and probably increases the risk of gastric cancer, but is not associated with OAC. Here, we review the current epidemiological evidence on associations between alcohol consumption, smoking and the risk of developing oesophago-gastric cancer, and emphasize the importance of focusing efforts on controlling the worldwide burden of oesophago-gastric cancer by reducing alcohol and tobacco use.

The Role of Esophagogastroduodenoscopy Surveillance for Patients with Barrett Esophagus

Approximately 10% to 15% of patients who experience chronic gastroesophageal reflux disease have Barrett esophagus, which is associated with an increased risk of esophageal adenocarcinoma. If symptoms persist after 8 weeks of adhering to treatment and lifestyle modifications, or if alarm symptoms develop, patients should be referred for screening upper endoscopy. Those with evidence of Barrett esophagus with dysplasia should be monitored in an endoscopic surveillance program, and those with high-grade dysplasia should consider surgical treatment.

Mechanisms of esophageal adenocarcinoma formation and approaches to chemopreventive intervention

The incidence of esophageal adenocarcinoma (EAC), a debilitating and highly lethal malignancy, has risen dramatically over the past 40 years in the United States and other Western countries. To reverse this trend, EAC prevention and early detection efforts by clinicians, academic researchers and endoscope manufacturers have targeted Barrett's esophagus (BE), the widely accepted EAC precursor lesion. Data from surgical, endoscopic and pre-clinical investigations strongly support the malignant potential of BE. For patients with BE, the risk of developing EAC has been estimated at 11- to 125-fold greater than that of the individual at average risk. Nevertheless, screening for BE in symptomatic patients (ie, with symptoms of reflux) and surveillance in patients diagnosed with BE have not had a substantial impact on the incidence, morbidity or mortality of EAC; the overwhelming majority of EAC patients are diagnosed without a pre-operative diagnosis of BE. This article will discuss the current state of the science of esophageal adenocarcinoma prevention, including ideas about carcinogenesis and its underlying genomic and molecular level mechanisms, and suggest strategies for a systems approach to targeted preventive management.

Recent developments in pathogenesis, diagnosis and therapy of Barrett's esophagus

The burden of illness from esophageal adenocarcinoma continues to rise in the Western world, and overall prognosis is poor. Given that Barrett’s esophagus (BE), a metaplastic change in the esophageal lining is a known cancer precursor, an opportunity to decrease disease development by screening and surveillance might exist. This review examines recent updates in the pathogenesis of BE and comprehensively discusses known risk factors. Diagnostic definitions and challenges are outlined, coupled with an in-depth review of management. Current challenges and potential solutions related to screening and surveillance are discussed. The effectiveness of currently available endoscopic treatment techniques, particularly with regards to recurrence following successful endotherapy and potential chemopreventative agents are also highlighted. The field of BE is rapidly evolving and improved understanding of pathophysiology, combined with emerging methods for screening and surveillance offer hope for future disease burden reduction.

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.

Smoking as an independent determinant of Barrett's esophagus and, to a lesser degree, of reflux esophagitis

PURPOSE

To evaluate the role of smoking in Barrett's esophagus (BE) and erosive esophagitis (E) compared to endoscopic controls with no BE or E. Smoking is considered a cause of both BE and E, but results on this topic are quite controversial.

METHODS

Patients with BE (339), E (462) and controls (619: 280 with GERD (gastroesophageal reflux disease)-negative and 339 with GERD-positive anamnesis) were recruited in 12 Italian endoscopy units. Data were obtained from structured questionnaires.

RESULTS

Among former smokers, a remarkable upward linear trend was found in BE for all smoking-related predictors. In particular, having smoked for more than 32 years increased the risk more than two times (OR 2.44, 95 % CL 1.33-4.45). When the analysis was performed in the subgroup of subjects with GERD-negative anamnesis, the risk of late quitters (<9 years) passed from OR 2.11 (95 % CL 1.19-3.72) to OR 4.42 (95 % CL 1.52-12.8). A noticeably positive dose-response relationship with duration was seen also among current smokers. As regards E, no straightforward evidence of association was detected, but for an increased risk of late quitters (OR 1.84, 95 % CL 1.14-2.98) in former smokers and for early age at starting (OR 3.63, 95 % CL 1.19-11.1) in GERD-negative current smokers.

CONCLUSIONS

Smoking seems to be an independent determinant of BE and, to a lesser degree, of E. The elevation in risk is independent from GERD and is already present in light cigarette smokers. Smoking cessation may reduce, but not remove this risk.

A review of the epidemiology of Barrett's oesophagus and oesophageal adenocarcinoma

While the incidence rates of many cancers have decreased in past decades, the incidence of oesophageal adenocarcinoma continues to increase. The only known precursor for oesophageal adenocarcinoma is Barrett's oesophagus. Studies conducted have identified white race, male sex, GORD, cigarette smoking, obesity, and the absence of Helicobacter pylori status as risk factors for oesophageal adenocarcinoma. Other potential associations include dietary factors and the absence of non-steroidal anti-inflammatory drug use. Many individual studies have been limited by sample size and several meta-analyses have pooled data from studies to address this limitation. In this review we present a synthesis of these studies and summarize current knowledge of risk factors for both oesophageal adenocarcinoma and Barrett's oesophagus.

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

BACKGROUND

Cigarette smoking has been associated with an increased risk of oesophageal adenocarcinoma (OAC). However, the impact of smoking and more importantly smoking cessation on Barrett's oesophagus (BO) is unclear.

OBJECTIVE

The aim of the study is to evaluate the association between cigarette smoking and presence of BO in a large prospective cohort of patients with gastro-oesophageal reflux disease (GORD).

METHODS

Patients presenting to the endoscopy unit for upper endoscopy completed a validated GORD questionnaire and information on demographics (age, gender, and ethnicity), cigarette smoking [status (current/past), amount (pack years) and duration of smoking cessation], clinical data [medication history, body mass index (BMI), and family history] and endoscopic findings [BO and hiatal hernia] were recorded. Cigarette smokers (current and past) and nonsmokers were compared using Fisher's Exact test for categorical variables and Mann-Whitney test for continuous variables. Effects of cigarette smoking and smoking cessation on BO risk was assessed by stepwise logistic regression analysis.

RESULTS

A total of 1056 patients were included in the analysis [mean age: 57.2 ± 12.7years, Caucasian 880 (83.3%), male 985 (93.3%), and mean BMI 29.6 (SD: ± 5.6)]. 827 (78.3%) were smokers and 229 (21.6%) were nonsmokers. 474 subjects (44.9%) had a previous history of smoking. Anytime smokers were more likely to have BO (adjusted OR: 3.3; 95 CI: 1.7-6.3; p < 0.01). Higher smoking burden (pack years) was associated with higher risk of BO in this GORD cohort (p for trend < 0.01). Duration of smoking cessation was inversely associated with risk of BO (p for trend: 0.01).

CONCLUSION

This study shows that smokers with reflux symptoms have about threefold higher risk of BO compared with nonsmokers, whereas discontinuing smoking is associated with a significant reduced risk. Smoking cessation appears to be a viable option to reduce BO risk in patients with reflux disease.

Gastro-esophageal reflux disease symptoms and demographic factors as a pre-screening tool for Barrett's esophagus

Background

Barrett’s esophagus (BE) occurs as consequence of reflux and is a risk factor for esophageal adenocarcinoma. The current “gold-standard” for diagnosing BE is endoscopy which remains prohibitively expensive and impractical as a population screening tool. We aimed to develop a pre-screening tool to aid decision making for diagnostic referrals.

Methodology/Principal Findings

A prospective (training) cohort of 1603 patients attending for endoscopy was used for identification of risk factors to develop a risk prediction model. Factors associated with BE in the univariate analysis were selected to develop prediction models that were validated in an independent, external cohort of 477 non-BE patients referred for endoscopy with symptoms of reflux or dyspepsia. Two prediction models were developed separately for columnar lined epithelium (CLE) of any length and using a stricter definition of intestinal metaplasia (IM) with segments ≥2 cm with areas under the ROC curves (AUC) of 0.72 (95%CI: 0.67–0.77) and 0.81 (95%CI: 0.76–0.86), respectively. The two prediction models included demographics (age, sex), symptoms (heartburn, acid reflux, chest pain, abdominal pain) and medication for “stomach” symptoms. These two models were validated in the independent cohort with AUCs of 0.61 (95%CI: 0.54–0.68) and 0.64 (95%CI: 0.52–0.77) for CLE and IM≥2 cm, respectively.

Conclusions

We have identified and validated two prediction models for CLE and IM≥2 cm. Both models have fair prediction accuracies and can select out around 20% of individuals unlikely to benefit from investigation for Barrett’s esophagus. Such prediction models have the potential to generate useful cost-savings for BE screening among the symptomatic population.

Role of chemoprophylaxis with either NSAIDs or statins in patients with Barrett's esophagus

The incidence of esophageal adenocarcinoma, a poor prognosis neoplasia, has risen dramatically in recent decades. Barrett's esophagus represents the best-known risk factor for esophageal adenocarcinoma development. Non-steroidal anti-inflammatory drugs through cyclooxygenase-2 inhibition and prostaglandin metabolism regulation could control cell proliferation, increase cell apoptosis and regulate the expression of growth and angiogenic factors. Statins can achieve equivalent effects through prenylation and subsequently control of cellular signaling cascades. At present, epidemiological studies are small and underpowered. Their data could not justify either medication as a chemo-preventive agent. Population based studies have shown a 43% reduction of the odds of developing an esophageal adenocarcinoma, leaving out or stating a 25% reduction in patients consuming non-aspirin nonsteroidal anti-inflammatory drugs and a 50% reduction in those patients consuming aspirin. They have also stated a 19% reduction of esophageal cancer incidence when statins have been used. Observational studies have shown that non-steroidal anti-inflammatory drugs could reduce the adenocarcinoma incidence in patients with Barrett's esophagus by 41%, while statins could reduce the risk by 43%. The cancer preventive effect has been enhanced in those patients taking a combination of non-steroidal anti-inflammatory drugs and statins (a 74% decrease). Observational data are equivocal concerning the efficacy of non-steroidal anti-inflammatory drug subclasses. Non-steroidal anti-inflammatory drugs clearly have substantial potential for toxicity, while statins are rather safe drugs. In conclusion, both non-steroidal anti-inflammatory drugs and statins are promising chemopreventive agents and deserve further exploration with interventional studies. In the meanwhile, their use is justified only in patients with cardiovascular disease.

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

Although endoscopic surveillance of patients with Barrett's oesophagus has been widely implemented, its effectiveness is debateable. The recently reported low annual oesophageal adenocarcinoma risk in population studies, the failure to identify most Barrett's patients at risk of disease progression, the poor adherence to surveillance and biopsy protocols, and the significant risk of misclassification of dysplasia all tend to undermine the effectiveness of current management, in particular, endoscopic surveillance programmes, to prevent or improve the outcomes of patients with oesophageal adenocarcinoma. The ongoing increase in incidence of Barrett's oesophagus and consequent growth of the surveillance population, together with the associated discomfort and costs of endoscopic surveillance, demand improved techniques for accurately determining individual risk of oesophageal adenocarcinoma. More accurate techniques are needed to run efficient surveillance programmes in the coming decades. In this review, we will discuss the current knowledge on the epidemiology of Barrett's oesophagus, and the challenging epidemiological dilemmas that need to be addressed when assessing the current screening and surveillance strategies.

No significant effects of smoking or alcohol consumption on risk of Barrett's esophagus

BACKGROUND

Smoking, but not higher alcohol consumption, is associated with increased risk of esophageal adenocarcinoma (EAC) and progression from Barrett's esophagus (BE) to EAC. However, it is still unclear whether smoking or alcohol is implicated in the development of BE.

AIM

To evaluate the associations between smoking, alcohol and the risk of BE.

METHODS

The study included eligible patients scheduled for elective esophagogastroduodenoscopy (EGD) and a sample of patients eligible for screening colonoscopy recruited from primary care clinics. We compared 258 patients with definitive BE with two separate control groups: 453 patients from the primary care group ("colonoscopy controls") and 1,145 patients from the elective EGD group ("endoscopy controls") with no endoscopic or histopathologic BE. We calculated odds ratios (OR) and 95 % confidence intervals (95 % CI) using multivariable logistic regression models.

RESULTS

Seventy-seven percent of BE cases, 75 % of colonoscopy controls and 72 % of endoscopy controls were ever smokers. Of these, approximately 45 % were current smokers. Overall, 91 % of study participants were ex or current alcohol drinkers, with the majority drinking beer. We found no association between various measure of smoking exposure (status, intensity, age at initiation, duration, pack-years and cessation) and risk of BE. Alcohol consumption was not associated with increased risk of BE. Conversely, moderate intake was associated with lower risk (14 to <28 drinks/week, OR 0.39, 95 % CI 0.15-1.00).

CONCLUSION

Smoking and alcohol were not strong or consistent risk factors for BE. The likely role of smoking in increasing risk of EAC is through promoting progression from BE to cancer.

Cigarette smoking and the risk of Barrett's esophagus: a systematic review and meta-analysis

BACKGROUND AND AIM

Barrett's esophagus (BE) is a premalignant condition to esophageal adenocarcinoma. It is currently not clear whether cigarette smoking increases the risk of developing BE, and no meta-analysis has been performed on the topic. We conducted a systematic review and meta-analysis, providing a quantitative estimate of the increased risk of BE associated with cigarette smoking, to help clarify whether a relationship exists between smoking and BE.

METHODS

Four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) were searched to May 17, 2013, for observational studies of BE patients. We calculated pooled odds ratios (ORs) and 95% confidence intervals (CIs) using a random effects model for the association of smoking with BE. BE patients were compared with non-gastroesophageal reflux disease (GERD) controls as well as with population-based and GERD controls.

RESULTS

Thirty-nine studies comprising 7069 BE patients were included in the meta-analysis. Having ever-smoked was associated with an increased risk of BE compared with non-GERD controls (OR 1.44; 95% CI 1.20-1.74), population-based controls (OR 1.42; 95% CI 1.15-1.76), but not GERD controls (OR 1.18; 95% CI 0.75-1.86). The meta-analyses of the studies reporting the lowest and highest number of pack-years smoked showed an increased risk of BE (OR 1.41; 95% CI 1.22-1.63) and (OR 1.53; 95% CI 1.27-1.84), respectively.

CONCLUSION

Cigarette smoking was associated with an increased risk of BE. Being an ever-smoker was associated with an increased risk of BE in all control groups. A greater number of pack-years smoked was associated with a greater risk of BE.

Epidemiology and risk factors for oesophageal adenocarcinoma

Oesophageal adenocarcinoma will soon cease to be a rare form of cancer for people born after 1940. In many Western countries, its incidence has increased more rapidly than other digestive cancers. Incidence started increasing in the Seventies in England and USA, 15 years later in Western Europe and Australia. The cumulative risk between the ages of 15 and 74 is particularly striking in the UK, with a tenfold increase in men and fivefold increase in women in little more than a single generation. Prognosis is poor with a 5-year relative survival rate of less than 10%. The main known risk factors are gastro-oesophageal reflux, obesity (predominantly mediated by intra-abdominal adipose tissues) and smoking. Barrett's oesophagus is a precancerous lesion, however, the risk of degeneration has been overestimated. In population-based studies the annual risk of adenocarcinoma varied between 0.12% and 0.14% and its incidence between 1.2 and 1.4 per 1000 person-years. Only 5% of subjects with Barrett's oesophagus die of oesophageal adenocarcinoma. On the basis of recent epidemiological data, new surveillance strategies should be developed. The purpose of this review is to focus on the epidemiology and risk factors of oesophageal adenocarcinoma.

Age at onset of GERD symptoms predicts risk of Barrett's esophagus

OBJECTIVES

Symptoms of gastroesophageal reflux disease (GERD) are the primary risk factor for Barrett's esophagus (BE). However, the significance of age at symptom onset is unknown. We examined the effects of multiple dimensions of GERD exposure on BE risk and whether these associations are modified by other risk factors for BE.

METHODS

Data were from a cross-sectional study of 683 Veterans Affairs patients undergoing an elective esophagogastroduodenoscopy (EGD) or a study EGD concurrently with colonoscopy from primary care clinics. We compared 236 patients with both endoscopically suspected and histologically confirmed BE to 447 primary-care patients ("primary-care controls") without endoscopically suspected BE on their study EGD. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate logistic regression.

RESULTS

Age at onset <30 years of frequent (at least weekly) GERD symptoms was associated with highest risk of BE (OR=15.1, 95% CI 7.91-28.8), and risk increased linearly with earlier age at onset of symptoms (P-trend=0.001). This association was independent of cumulative GERD symptom duration. People with early onset GERD symptoms who reported ever using proton pump inhibitors were at especially high risk of BE (OR=31.1, 95% CI 13.9-69.7). In people with frequent GERD symptoms, BE risk was almost 80% lower among Helicobacter pylori-positive patients (OR=2.60, 95% CI 1.26-5.40) than those negative for H. pylori (OR=8.24, 95% CI 5.00-13.6).

CONCLUSIONS

Risk of BE increased linearly with earlier age at onset of frequent GERD symptoms. Age at symptom onset may help practitioners decide which patients with GERD symptoms to refer for endoscopic screening for BE.

Risk factors in the development of esophageal adenocarcinoma

OBJECTIVES

It is assumed that esophageal adenocarcinoma is the end result of a stepwise disease process that transitions through gastroesophageal reflux disease (GERD) and Barrett's esophagus. The aim of this study was to examine at what stage known risk factors exert their influence toward the progression to cancer.

METHODS

We enrolled 113 consecutive outpatients without GERD, 188 with GERD, 162 with Barrett's esophagus, and 100 with esophageal adenocarcinoma or high-grade dysplasia (HGD). All patients underwent a standard upper endoscopy and completed a standardized questionnaire about their social history, symptoms, dietary habits, and prescribed medications. We used adjusted logistic regression analysis to assess risk factors between each two consecutive disease stages from the absence of reflux disease to esophageal adenocarcinoma.

RESULTS

Overall, male gender, smoking, increased body mass index (BMI), low fruit and vegetable intake, duration of reflux symptoms, and presence of a hiatal hernia were risk factors for cancer/HGD. However, different combinations of risk factors were associated with different disease stages. Hiatal hernia was the only risk factor to be strongly associated with the development of GERD. For GERD patients, male gender, age, an increased BMI, duration of reflux symptoms, and presence of a hiatal hernia were all associated with the development of Barrett's esophagus. Finally, the development of cancer/HGD among patients with Barrett's esophagus was associated with male gender, smoking, decreased fruit and vegetable intake, and a long segment of Barrett's esophagus, but not with age, BMI, or a hiatal hernia.

CONCLUSIONS

While some risk factors act predominantly on the initial development of reflux disease, others appear to be primarily responsible for the development of more advanced disease stages.

The role of tobacco, alcohol, and obesity in neoplastic progression to esophageal adenocarcinoma: a prospective study of Barrett's esophagus

BACKGROUND

Esophageal adenocarcinoma (EA) incidence in many developed countries has increased dramatically over four decades, while survival remains poor. Persons with Barrett's esophagus (BE), who experience substantially elevated EA risk, are typically followed in surveillance involving periodic endoscopy with biopsies, although few progress to EA. No medical, surgical or lifestyle interventions have been proven to safely lower EA risk.

DESIGN

We investigated whether smoking, obesity or alcohol could predict progression to EA in a prospective cohort of 411 BE patients. Data were collected during personal interview. Adjusted hazard ratios (HR) were estimated using Cox regression.

RESULTS

39% had body mass index (BMI) over 30 and 64% had smoked cigarettes. Main analyses focused on those with at least 5 months of follow-up (33,635 person-months), in whom 45 developed EA. Risk increased by 3% per year of age (trend p-value 0.02), with approximate doubling of risk among males. EA risk increased with smoking pack-years (trend p-value 0.04) and duration (p-value 0.05). Compared to never-smokers, the HR for those in the highest pack-year tertile was 2.29 (95%CI 1.04-5.07). No association was found with alcohol or BMI, whereas a suggestion of increased risk was observed in those with higher waist-hip ratio, especially among males.

CONCLUSION

EA risk significantly increased with increasing age and cigarette exposure. Abdominal obesity, but not BMI, was associated with a modest increased risk. Continued follow-up of this and other cohorts is needed to precisely define these relationships so as to inform risk stratification and preventive interventions.

A clinical risk prediction model for Barrett esophagus

Barrett esophagus is the only known precursor to esophageal adenocarcinoma. As definitive diagnosis requires costly endoscopic investigation, we sought to develop a risk prediction model to aid in deciding which patients with gastroesophageal reflux symptoms to refer for endoscopic screening for Barrett esophagus. The study included data from patients with incident nondysplastic Barrett esophagus (n = 285) and endoscopy control patients with esophageal inflammatory changes without Barrett esophagus ("inflammation controls", n = 313). We used two phases of stepwise backwards logistic regression to identify the important predictors for Barrett esophagus in men and women separately: first, including all significant covariates from univariate analyses and then fitting non-significant covariates from univariate analyses to identify those effects detectable only after adjusting for other factors. The final model pooled these predictors and was externally validated for discrimination and calibration using data from a Barrett esophagus study conducted in western Washington State. The final risk model included terms for age, sex, smoking status, body mass index, highest level of education, and frequency of use of acid suppressant medications (area under the ROC curve, 0.70; 95%CI, 0.66-0.74). The model had moderate discrimination in the external dataset (area under the ROC curve, 0.61; 95%CI, 0.56-0.66). The model was well calibrated (Hosmer-Lemeshow test, P = 0.75), with predicted probability and observed risk highly correlated. The prediction model performed reasonably well and has the potential to be an effective and useful clinical tool in selecting patients with gastroesophageal reflux symptoms to refer for endoscopic screening for Barrett esophagus.

Cigarette smoking increases risk of Barrett's esophagus: an analysis of the Barrett's and Esophageal Adenocarcinoma Consortium

BACKGROUND & AIMS

Cigarette smoking has been implicated in the etiology of esophageal adenocarcinoma, but it is not clear if smoking is a risk factor for Barrett's esophagus. We investigated whether tobacco smoking and other factors increase risk for Barrett's esophagus.

METHODS

We analyzed data from 5 case-control studies included in the international Barrett's and Esophageal Adenocarcinoma Consortium. We compared data from subjects with Barrett's esophagus (n = 1059) with those from subjects with gastroesophageal reflux disease (gastroesophageal reflux disease controls, n = 1332), and population-based controls (n = 1143), using multivariable logistic regression models to test associations with cigarette smoking. We also tested whether cigarette smoking has synergistic effects with other exposures, which might further increase risk for Barrett's esophagus.

RESULTS

Subjects with Barrett's esophagus were significantly more likely to have ever smoked cigarettes than the population-based controls (odds ratio [OR] = 1.67; 95% confidence interval [CI]: 1.04-2.67) or gastroesophageal reflux disease controls (OR = 1.61; 95% CI: 1.33-1.96). Increasing pack-years of smoking increased the risk for Barrett's esophagus. There was evidence of a synergy between ever-smoking and heartburn or regurgitation; the attributable proportion of disease among individuals who ever smoked and had heartburn or regurgitation was estimated to be 0.39 (95% CI: 0.25-0.52).

CONCLUSIONS

Cigarette smoking is a risk factor for Barrett's esophagus. The association was strengthened with increased exposure to smoking until ∼20 pack-years, when it began to plateau. Smoking has synergistic effects with heartburn or regurgitation, indicating that there are various pathways by which tobacco smoking might contribute to development of Barrett's esophagus.

Risk factors and chemoprevention in Barrett's esophagus--an update

OBJECTIVE

Barrett's esophagus (BO) is a precursor of esophageal adenocarcinoma (OAC), a cancer with a poor prognosis and an increasing incidence. Hence there is an interest in mapping causal factors underlying BO and finding strategies to reduce the risk of dysplasia progression in patients with BO. Here we review current knowledge on established as well as less risk factors for the development of BO. Additionally, we summarize today's status on the use of chemoprevention aiming to reduce the risk of cancer progression in BO patients.

METHODS

We searched Medline and the Cochrane Library using the MeSH terms "Barrett's esophagus" and "Barrett esophagus," both alone and combined with the terms "risk factor," "aetiology," "diet," or "prevention." Focus was on original contributions, systematic reviews, and meta-analyses.

RESULTS

Established risk factors for the development of BO include gastro-esophageal reflux, obesity, male gender, Caucasian ethnicity, and increasing age. Smoking might increase the risk of BO, while aspirin/NSAIDs, Helicobacter pylori infection, and specific "healthy" dietary factors may lower the risk. The potential value of using chemoprevention with proton pump inhibitors, aspirin/NSAIDs, or statins is still uncertain.

CONCLUSIONS

There is today a substantial knowledge of risk factors of BO. Certain diet may be protective of BO, albeit yet to be proven. The efficiency of chemoprevention in BO is currently addressed further in randomized clinical trials.

Current status and future perspectives on the etiology of esophageal adenocarcinoma

Esophageal adenocarcinoma is the most common type of esophageal cancer in most Western countries and is an important contributor to overall cancer mortality. Most cases of esophageal adenocarcinoma are believed to arise from Barrett’s esophagus. Esophageal adenocarcinoma occurs more frequently in white men over 50 years old, as well as in people with frequent symptoms of gastroesophageal reflux, in smokers and in people who are obese. Higher consumption of fruit and vegetables, use of non-steroidal anti-inflammatory drugs, and infection with Helicobacter pylori have all been shown to reduce the risk of esophageal adenocarcinoma. Here, we review the epidemiological evidence for the major risk factors of esophageal adenocarcinoma and also discuss perspectives for future research.

The use of nonsteroidal anti-inflammatory drugs and the risk of Barrett's oesophagus

BACKGROUND

Epidemiological studies have consistently reported inverse associations between nonsteroidal anti-inflammatory drugs (NSAIDs) and oesophageal adenocarcinoma, but few have investigated associations with the precursor lesion, Barrett's oesophagus.

AIM

To investigate the relationship between NSAID use and risk of Barrett's oesophagus.

METHODS

We conducted a large population-based case-control study that collected information on patterns of intake for aspirin and non-aspirin NSAIDs during the past 5 years and other exposures from 285 patients with nondysplastic Barrett's oesophagus, 108 patients with dysplastic Barrett's oesophagus, and two separate control groups: 313 endoscopy patients with acute inflammatory changes ('inflammation controls') and 644 population controls. We calculated odds ratios (ORs) and 95% CIs using unconditional logistic regression.

RESULTS

Use of aspirin was not associated with nondysplastic Barrett's oesophagus when compared with population (OR=1.01, 95% CI 0.71-1.43) or inflammation controls (OR=1.16, 95% CI 0.80-1.68). Whereas we observed significant risk reductions for use of non-aspirin NSAIDs when nondysplastic Barrett's oesophagus cases were compared with population controls (OR=0.69, 95% CI 0.49-0.97), the effect was weaker and nonsignificant when cases were compared with inflammation controls (OR=0.82, 95% CI 0.57-1.18), and no dose-response effects were present in either analysis. We found no evidence that aspirin or non-aspirin NSAID use conferred risk reductions for dysplastic Barrett's oesophagus, regardless of the control series. We excluded effect modification by known risk factors as an explanation for these null findings.

CONCLUSIONS

We found little support for an inverse association between use of NSAIDs and Barrett's oesophagus. The question of whether or not these medications prevent the onset of Barrett's oesophagus remains open.

Helicobacter pylori infection and the risks of Barrett's oesophagus: a population-based case-control study

Infection with Helicobacter pylori is associated with significantly reduced risks of oesophageal adenocarcinoma; however, few studies have examined the association between H. pylori and Barrett's oesophagus (BO), the precursor lesion. We explored the relationship between H. pylori infection and BO and sought to identify potential modifiers. We compared the prevalence of positive H. pylori serology among 217 adults with simple BO (without dysplasia), 95 with dysplastic BO and 398 population controls sourced from the metropolitan Brisbane area. We determined H. pylori serostatus using enzyme-linked immunosorbent assay. To estimate relative risks, we calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariable logistic regression in the entire sample and stratified by factors known to cause BO. The prevalence of H. pylori seropositivity was 12%, 3%, and 18%, respectively, among patients with simple BO, dysplastic BO and population controls. BO patients were significantly less likely to have antibodies for H. pylori (Simple BO: OR = 0.51, 95% CI: 0.30-0.86; Dysplastic BO: OR = 0.10, 95% CI: 0.03-0.33) than population controls. For simple BO, the association was diminished after adjustment for frequency of gastro-oesophageal reflux (GOR) symptoms. Adjustment for frequency of GOR symptoms did not substantially alter the observed effect for dysplastic BO. Although there was some variation in the magnitude of risk estimates across strata of age, sex, GOR symptoms and use of proton pump inhibitors or H2-receptor antagonists, the differences were uniformly nonsignificant. Helicobacter pylori infection is inversely associated with BO, and our findings suggest that decreased acid load is not the only mechanism underlying the H. pylori protective effect.

Whole genome expression array profiling highlights differences in mucosal defense genes in Barrett's esophagus and esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) has become a major concern in Western countries due to rapid rises in incidence coupled with very poor survival rates. One of the key risk factors for the development of this cancer is the presence of Barrett's esophagus (BE), which is believed to form in response to repeated gastro-esophageal reflux. In this study we performed comparative, genome-wide expression profiling (using Illumina whole-genome Beadarrays) on total RNA extracted from esophageal biopsy tissues from individuals with EAC, BE (in the absence of EAC) and those with normal squamous epithelium. We combined these data with publically accessible raw data from three similar studies to investigate key gene and ontology differences between these three tissue states. The results support the deduction that BE is a tissue with enhanced glycoprotein synthesis machinery (DPP4, ATP2A3, AGR2) designed to provide strong mucosal defenses aimed at resisting gastro-esophageal reflux. EAC exhibits the enhanced extracellular matrix remodeling (collagens, IGFBP7, PLAU) effects expected in an aggressive form of cancer, as well as evidence of reduced expression of genes associated with mucosal (MUC6, CA2, TFF1) and xenobiotic (AKR1C2, AKR1B10) defenses. When our results are compared to previous whole-genome expression profiling studies keratin, mucin, annexin and trefoil factor gene groups are the most frequently represented differentially expressed gene families. Eleven genes identified here are also represented in at least 3 other profiling studies. We used these genes to discriminate between squamous epithelium, BE and EAC within the two largest cohorts using a support vector machine leave one out cross validation (LOOCV) analysis. While this method was satisfactory for discriminating squamous epithelium and BE, it demonstrates the need for more detailed investigations into profiling changes between BE and EAC.

Risk factors for Barrett's esophagus in Indian patients with gastroesophageal reflux disease

BACKGROUND AND AIMS

Barrett's esophagus (BE) is reported to be infrequent in Asians, with no data from India regarding its prevalence and risk factors. We investigated the frequency and risk factors of columnar mucosa with or without specialized intestinal metaplasia (SIM) in Indian patients with gastroesophageal reflux disease (GERD).

METHODS

A total of 278 GERD patients over 2 years underwent gastroscopy and completed a questionnaire for possible BE risk factors. Patients with columnar mucosa on endoscopy underwent four-quadrant biopsy; BE was histologically defined as columnar mucosa with or without SIM. Patients without columnar mucosa at endoscopy were considered as controls and compared to patients with BE and those with SIM.

RESULTS

Forty-six patients with GERD had columnar mucosa on histology (16.54%); 25 (8.99%) of these had SIM. The risk factors for BE were the presence of hiatus hernia (odds ratio [OR]: 3.14; 95% confidence interval [CI]: 1.2-8.17) and a history of eructation (OR: 2.28; CI: 1.11-4.66). The risk factors for SIM were age ≥ 45 years (OR: 2.63; CI: 1.03-6.71), hiatus hernia (OR: 3.95; CI: 1.24-12.56), and a history of eructation (OR: 3.41; CI: 1.19-9.78). Sex, severity of symptoms, dietary factors, tobacco or alcohol use, and body mass index were not associated with BE. The median circumferential segment length was 2 (1-10) cm, and the maximal length was 3 (2-11) cm in both groups.

CONCLUSION

BE is not an uncommon finding among Indian GERD patients. Age ≥ 45 years, history of eructation, and the presence of hiatus hernia are associated with SIM.

Lifetime alcohol consumption and risk of Barrett's Esophagus

OBJECTIVES

Alcohol is a carcinogen that may increase the risk of Barrett's esophagus (BE) through direct contact with esophageal mucosa. However, few studies have investigated this association and findings have been inconsistent. We sought to examine the association between measures of total and beverage-specific alcohol consumption and BE risk.

METHODS

We conducted a large population-based case-control study that collected information on lifetime alcohol consumption and other exposures from 285 patients with nondysplastic BE, 108 patients with dysplastic BE, and two separate control groups: 313 endoscopy patients with acute inflammatory changes ("inflammation controls") and 644 population controls. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for categories of average alcohol consumption using unconditional multivariate logistic regression.

RESULTS

Relative to life-long nondrinkers and consumption of <1 drink/week, consumption of 7-20 drinks/week (OR=0.53, 95% CI: 0.31-0.91) and 21-41 drinks/week (OR=0.37, 95% CI: 0.19-0.73) of total alcohol throughout the life was inversely associated with nondysplastic BE, for comparisons with population controls. Lifetime total alcohol consumption was also inversely associated with dysplastic BE (7-20 drinks/week OR=0.52, 95% CI: 0.19-1.43; 21-41 drinks/week OR=0.22, 95% CI: 0.07-0.73). Similarly, reduced risk estimates were found for comparisons with inflammation controls. The inverse associations were observed separately for beer and wine consumption, with a significant linear trend observed with beer consumption. The risks associated with liquor consumption were up to twofold higher; however, they were not statistically significant. We found no evidence for effect modification by factors known (or suspected) to cause BE.

CONCLUSIONS

Overall, alcohol consumption does not increase the risk of BE. Significant inverse associations were observed for beer consumption, the underlying reasons for which remain unclear.

Influence of obesity on the risk of esophageal disorders

Obesity is associated with an increased risk of esophageal disorders, including esophageal adenocarcinoma, Barrett esophagus and GERD. For reasons yet unknown, the association between obesity and esophageal adenocarcinoma seems to be stronger than that for other types of obesity-related cancers. Predominantly abdominal or intra-abdominal adiposity (representing visceral fat and other fat within the abdominal cavity), which is more frequently observed in men than in women, is more strongly linked with these esophageal disorders than BMI alone, a finding that might contribute to the striking male predominance of esophageal adenocarcinoma. Research has identified potential mechanisms underlying the strong link between obesity and esophageal conditions. These findings are summarized in this Review, but more research remains to be carried out before these mechanisms are established.

Smoking and Barrett's esophagus in women who undergo upper endoscopy

BACKGROUND

Cigarette use is associated with esophageal adenocarcinoma, and cross-sectional studies suggest an association between smoking and Barrett's esophagus.

AIMS

We sought to examine prospectively the effect of smoking on the risk for Barrett's esophagus.

METHODS

This was a prospective cohort study among 20,863 women within the Nurses' Health Study who underwent upper gastrointestinal endoscopy for any reason between 1980 and 2006. We assessed the association between smoking and pathologically-confirmed Barrett's esophagus (n = 377). Self-reported data on smoking and potential confounding variables were collected from biennial questionnaires.

RESULTS

Compared with women who never smoked, former smokers of 1-24 cigarettes/day had a multivariate odds ratio for Barrett's esophagus of 1.25 (95% CI 0.99-1.59), former smokers of ≥ 25 cigarettes/day had a multivariate odds ratio of 1.52 (95% CI 1.04-2.22), current smokers of 1-24 cigarettes/day had a multivariate odds ratio of 0.89 (95% CI 0.54-1.45), and current smokers of ≥ 25 cigarettes/day had a multivariate odds ratio of 0.92 (95% CI 0.34-2.54). The risk for Barrett's esophagus increased significantly with increasing pack-years smoked among former (P = 0.008) but not current smokers (P = 0.99), especially when considering exposure ≥ 25 years before index endoscopy. Results were similar among women reporting regular heartburn/acid-reflux one or more times a week, and were not accounted for by changes in weight.

CONCLUSIONS

Heavy, remote smoking is associated with an increased risk for Barrett's esophagus. This finding suggests a long latency period between exposure and development of the disease, even after discontinuation of smoking.

Barrett's esophagus

Barrett's esophagus is an acquired metaplastic abnormality in which the normal stratified squamous epithelium lining of the esophagus is replaced by an intestinal-like columnar epithelium. While in itself a benign and asymptomatic disorder, the clinical importance of this relatively common condition relates to its role as a precursor lesion to esophageal adenocarcinoma, the incidence of which has dramatically increased in Western populations in recent years. Although known to arise as a consequence of chronic gastroesophageal reflux, the cellular and molecular mechanisms underlying development Barrett's esophagus and its progression to cancer remain unclear.

High intake of folate from food sources is associated with reduced risk of esophageal cancer in an Australian population

Folate plays a key role in DNA synthesis and methylation. Limited evidence suggests high intake may reduce risks of esophageal cancer overall; however, associations with esophageal cancer subtypes and Barrett's esophagus (BE), a precancerous lesion, remain unexplored. We evaluated the relation between intake of folate, B vitamins, and methyl-group donors (methionine, choline, betaine) from foods and supplements, polymorphisms in key folate-metabolizing genes, and risk of BE, esophageal adenocarcinoma (EAC), and esophageal squamous cell carcinoma (ESCC) in 2 population-based case-control studies in Australia. BE patients without (n = 266) or with (n = 101) dysplasia were compared with population controls (n = 577); similarly, EAC (n = 636) or ESCC (n = 245) patients were compared with population controls (n = 1507) using multivariable adjusted logistic regression. Increasing intake of folate from foods was associated with reduced EAC risk (P-trend = 0.01) and mitigated the increased risks of ESCC associated with smoking and alcohol consumption. In contrast, high intake of folic acid from supplements was associated with a significantly elevated risk of BE with dysplasia. High intakes of riboflavin and methionine from food were associated with increased EAC risk, whereas increasing betaine intake was associated with reduced risks of BE without (P-trend = 0.004) or with dysplasia (P-trend = 0.02). Supplemental thiamin, riboflavin, niacin, and vitamin B-12 were associated with increased EAC risk. There were no consistent associations between genetic polymorphisms studied and BE or EAC risk. High intake of folate-containing foods may reduce risk of EAC, but our data raise the possibility that folic acid supplementation may increase risks of BE with dysplasia and EAC.

Global epidemiology of Barrett's esophagus

Barrett's esophagus (BE) is defined as a metaplastic change of the distal esophageal epithelium from squamous to columnar type epithelium with the presence of intestinal metaplasia. There is a striking geographic variation in the prevalence rates of BE. Most epidemiological data on BE are derived from patients undergoing endoscopy and do not reflect prevalence rates in the general population. BE is much more common in the West when compared with Asia and Africa. Although BE is less common in Asia, the demographics are similar to the West, being predominantly found in older men with longer duration of reflux symptoms. Some studies from the West have suggested an increase in prevalence rates of BE. An increase in prevalence rates will have significant implications for health resource utilization and costs, due to the small but significant risk of developing esophageal adenocarcinoma. Endoscopic surveillance with the aim of detecting early lesions has been advocated. Compared with conventional white-light endoscopy with blind four-quadrant biopsies, the use of image-enhanced endoscopy, including chromoendoscopy, may improve detection of subtle mucosal irregularities and facilitate targeted biopsies. However, a truly cost-effective surveillance strategy remains to be determined.

A prospective cohort study on overweight, smoking, alcohol consumption, and risk of Barrett's esophagus

BACKGROUND

Barrett's esophagus (BE) is a precursor lesion of esophageal adenocarcinoma. Besides gastroesophageal reflux, possible risk factors for BE include overweight, cigarette smoking, and alcohol consumption. Our objective was to study these associations by using prospective data.

METHODS

The prospective Netherlands Cohort Study, initiated in 1986, consists of 120,852 men and women, aged 55 to 69 years at baseline. At baseline, all subjects completed a questionnaire on dietary habits and lifestyle. After 16.3 years of follow-up, 370 BE cases with specialized intestinal metaplasia and 3,866 subcohort members were available for case-cohort analysis. Cox proportional hazards models were used to calculate incidence rate ratios (RR) and 95% CIs.

RESULTS

Body mass index (BMI) at baseline was associated with risk of BE in women [multivariable adjusted RR per 1 kg/m(2), 1.07 (1.03-1.11)] but not in men [RR per 1 kg/m(2), 0.99 (0.93-1.05)]. The association in women was not specifically due to abdominal overweight. Former cigarette smokers were at increased risk of BE (RR = 1.33, 95% CI: 1.00-1.77), but current smokers were not. Smoking duration showed a positive association with BE risk (P(trend) = 0.03). For alcohol consumption, the RR per 10 g ethanol/d was 0.95 (0.87-1.03).

CONCLUSIONS

Increased BMI was a risk factor for BE in women but not in men. Several aspects of cigarette smoking were positively associated with BE risk. Alcohol consumption was not associated with an increased risk of BE.

IMPACT

Future research should focus on risk factors both for development and for progression of BE to esophageal adenocarcinoma.

When to consider endoscopic ablation therapy for Barrett's esophagus

PURPOSE OF REVIEW

To evaluate timing and patient selection for endoscopic ablative therapy in Barrett's esophagus.

RECENT FINDINGS

There has been an explosion in the literature describing ablative therapy in Barrett's esophagus. Most recent data describe radiofrequency ablation (RFA), but other data pertain to photodynamic therapy (PDT) and other modalities. Most studies are cohort or case series. Reversion to squamous epithelium is the most common primary outcome. Cancer incidence data are scarce. RFA appears well tolerated. The main side-effect is chest pain, which can be managed with oral analgesics. Stricture occurs in 0-8% and is amenable to endoscopic dilatation. Infrequent side-effects include bleeding and perforation. Complete reversion to squamous epithelium occurs in more than 90% of nondysplastic and low-grade dysplasia and more than 80% in high-grade dysplasia patients, and the treatment appears durable for at least 2-5 years of available follow-up. Treatment of low-grade or nondysplastic disease may be cost-effective. PDT data suggest that all-cause mortality is similar to surgery for dysplastic Barrett's esophagus. The stricture rate appears higher, and rates of complete reversion to neosquamous epithelium are lower than that of RFA, although definitive comparisons are lacking.

SUMMARY

The excellent efficacy, side-effect profile, and cost-effectiveness appear to make RFA the intervention of choice in cases of high-grade dysplasia. RFA for low-grade dysplasia may be of value in young patients and/or those with long segment or multifocal disease. Treatment of nondysplastic Barrett's esophagus is of uncertain value. PDT appears to have a higher stricture rate and to be more expensive than RFA.

Barrett's oesophagus and oesophageal adenocarcinoma: time for a new synthesis

The public health importance of Barrett's oesophagus lies in its association with oesophageal adenocarcinoma. The incidence of oesophageal adenocarcinoma has risen at an alarming rate over the past four decades in many regions of the Western world, and there are indications that the incidence of this disease is on the rise in Asian populations in which it has been rare. Much has been learned of host and environmental risk factors that affect the incidence of oesophageal adenocarcinoma, and data indicate that patients with Barrett's oesophagus rarely develop oesophageal adenocarcinoma. Given that 95% of oesophageal adenocarcinomas arise in individuals without a prior diagnosis of Barrett's oesophagus, what strategies can be used to reduce late diagnosis of oesophageal adenocarcinoma?