Lifetime alcohol consumption and risk of Barrett's Esophagus

Prevalence and beverage-related risk factors of gastroesophageal reflux disease: An original study in Chinese college freshmen, a systemic review and meta-analysis

BACKGROUND

Beverage-drinking behavior could be a potential risk factor for gastroesophageal reflux disease (GERD) in young populations. However, GERD prevalence in this population has not been investigated, and beverage consumption's association with GERD remains inconclusive. This study aimed to evaluate the prevalence and beverage-related risk factors of GERD among Chinese college freshmen and in youth around the world.

METHODS

A cross-sectional survey was conducted in Chinese college freshmen in September 2019 using random cluster sampling method. Participants completed questionnaires on demographic information, food intake frequency, and GER symptoms. Multivariate logistic regression models were applied to assess the association between beverages and GERD. Studies were retrieved from multiple databases for systemic review. The prevalence of GERD in young populations and beverage-related risk factors were pooled using random-effect models.

KEY RESULTS

Based on the 3345 individuals who completed the questionnaires, GERD prevalence in Chinese college freshmen is 5.1%. Multivariate analysis showed students who drink green tea daily, and those who drink coffee regularly were more likely to develop GERD compared with those who never drink tea or coffee. The pooled prevalence of GERD in young populations is 18.0%, and frequent alcohol consumption is positively associated with GERD in general population.

CONCLUSIONS AND INFERENCES

The prevalence of GERD in Chinese college freshmen is significantly lower than that in worldwide youth populations. Alcohol, green tea, and coffee consumption could be potential risk factors for GERD. Future large-scale epidemiological studies are warranted for reliable identification of beverage-related risk factors for GERD in young populations.

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.

Dietary and Lifestyle Factors Related to Gastroesophageal Reflux Disease: A Systematic Review

We performed this review to clarify which dietary and lifestyle factors are related to gastroesophageal reflux disease. Through a systematic search of the PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Chinese BioMedical Literature (CBM) databases, we identified articles with clear definitions of GERD, including nonerosive gastroesophageal reflux disease (NERD), reflux esophagitis (RE) and Barrett’s esophagus (BE), that included dietary and lifestyle factors as independent factors affecting the onset of GERD (expressed as odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs)). Due to heterogeneity among the studies, we used descriptive statistical analyses to analyze and synthesize each outcome based on the disease type. In total, 72 articles were included, conducted in ten Western countries (26 articles in total) and nine Eastern countries (46 articles in total). We categorized dietary factors into 20 items and lifestyle factors into 11 items. GERD is related to many irregular dietary and lifestyle habits (such as a habit of midnight snacking: OR=5.08, 95% CI 4.03–6.4; skipping breakfast: OR=2.7, 95% CI 2.17–3.35; eating quickly: OR=4.06, 95% CI 3.11–5.29; eating very hot foods: OR=1.81, 95% CI 1.37–2.4; and eating beyond fullness: OR=2.85, 95% CI 2.18–3.73). Vegetarian diets (consumption of nonvegetarian food (no/yes); OR=0.34, 95% CI 0.211–0.545) and no intake of meat (OR=0.841, 95% CI 0.715–0.990) were negatively related to GERD, while meat (daily meat, fish, and egg intake: OR=1.088, 95% CI 1.042-1.135) and fat (high–fat diet: OR=7.568, 95% CI 4.557–8.908) consumption were positively related to GERD. An interval of less than three hours between dinner and bedtime (OR=7.45, 95% CI 3.38–16.4) was positively related to GERD, and proper physical exercise (physical exercise >30 minutes (>3 times/week): OR=0.7, 95% CI 0.6–0.9) was negatively correlated with GERD. Smoking (OR=1.19, 95% CI 1.12–1.264), alcohol consumption (OR=1.278, 95% CI 1.207–1.353) and mental state (poor mental state: OR=1.278, 95% CI 1.207–1.353) were positively correlated with GERD. RE (vitamin C: OR=0.46, 95% CI=0.24–0.90) and BE (vitamin C: OR=0.44,95% CI 0.2-0.98; vitamin E: OR=0.46, 95% CI 0.26–0.83) were generally negatively correlated with antioxidant intake. In conclusion, many dietary and lifestyle factors affect the onset of GERD, and these factors differ among regions and disease types. These findings need to be further confirmed in subsequent studies.

Barrett oesophagus

Barrett oesophagus (BE), the only known histological precursor of oesophageal adenocarcinoma (EAC), is a condition in which the squamous epithelium of the oesophagus is replaced by columnar epithelium as an adaptive response to gastro-oesophageal reflux. EAC has one of the fastest rising incidences of cancers in Western countries and has a dismal prognosis. BE is usually detected during endoscopic examination, and diagnosis is confirmed by the histological presence of intestinal metaplasia. Advances in genomics and transcriptomics have improved our understanding of the pathogenesis and malignant progression of intestinal metaplasia. As the majority of EAC cases are diagnosed in individuals without a known history of BE, screening for BE could potentially decrease disease-related mortality. Owing to the pre-malignant nature of BE, endoscopic surveillance of patients with BE is imperative for early detection and treatment of dysplasia to prevent further progression to invasive EAC. Developments in endoscopic therapy have resulted in a major shift in the treatment of patients with BE who have dysplasia or early EAC, from surgical resection to endoscopic resection and ablation. In addition to symptom control by optimization of lifestyle and pharmacological therapy with proton pump inhibitors, chemopreventive strategies based on NSAIDs and statins are currently being investigated for BE management.

Maximizing Polyphenol Content to Uncork the Relationship Between Wine and Cancer

Studies have revealed conflicting results regarding the risk of cancer from alcohol consumption. Furthermore, some studies have suggested that wine may have benefits that separate it from other alcoholic beverages. As wine contains a significant amount of chemicals, specifically polyphenols like anthocyanins and proanthocyanidins (PA), that can affect cellular function and promote health, this hypothesis is reasonably supported by recent research. Polyphenols promote several anticancer cellular pathways, including xenobiotic metabolism, support of innate antioxidant production, and stimulation of phase I and II detoxification of carcinogens. However, the multitude of growing and production conditions of grapes, including temperature, water availability, soil type, maceration, and aging can result in a remarkably varying final product based on the available literature. Thus, we hypothesize that wines produced from grapes cultivated between steady daily temperatures at 15–25°C with moderate sun exposure from flowering to harvest, lower vine-water status, resulting either from lower precipitation, and irrigation practices or more permeable soil types, limitation of fertilizers, extended maceration, and aging in oak will impact the concentration of anthocyanins and PA in the finished wine and may have a differential impact on cancer. This higher concentration of polyphenols would, in theory, create a healthier wine, thus explaining the conflicting reports on the benefits or harms of wine.

Smokeless Tobacco and Cigar and/or Pipe Are Risk Factors for Barrett Esophagus in Male Patients With Gastroesophageal Reflux Disease

OBJECTIVE

To investigate the effect of smokeless tobacco (ST), cigar and/or pipe smoking (CP) on the development of Barrett esophagus (BE) in white male patients with gastroesophageal reflux disease (GERD).

PATIENTS AND METHODS

A total of 1015 records of white male adults with BE (cases; n=508) or GERD (controls, n=507) were reviewed for lifestyle factors. Logistic regression analyses were performed after adjusting for lifestyle factors to assess the effects of ST and CP on the risk of developing BE. Differences between patients with BE and those with GERD were compared using chi-square and t tests.

RESULTS

Patients with BE were significantly older than patients with GERD (mean age, 66±12 years for patients with BE and 55±15 years for patients with GERD; P<.001). The odds of developing BE in patients who used CS were 1.7 times higher than that in patients who never smoked cigarettes (odds ratio [OR], 1.7; 95% CI, 1.3-2.2). It was observed that when CS use was combined with either ST or CP use, the odds of having BE significantly increased (OR, 2.5; 95% CI, 1.2-5.2; P=.01 and OR, 1.9; 95% CI, 1.03-3.58; P=.04) in comparison to CS alone. There were no significant differences in body mass index and alcohol consumption between BE and GERD groups.

CONCLUSION

This study suggests that there is indeed an association between CS and BE. We believe that this is the first time that ST and CP were associated with an even higher odds of developing BE. Further studies are needed to investigate whether the use of ST and CP is also associated with an increased risk of developing BE-associated adenocarcinoma.

Contribution of Red Wine Consumption to Human Health Protection

Wine consumption has been popular worldwide for many centuries. Based on in vitro and in vivo studies, a certain amount of everyday wine consumption may prevent various chronic diseases. This is due, in part, to the presence and amount of important antioxidants in red wine, and, therefore, research has focused on them. Wine polyphenols, especially resveratrol, anthocyanins, and catechins, are the most effective wine antioxidants. Resveratrol is active in the prevention of cardiovascular diseases by neutralizing free oxygen radicals and reactive nitrogenous radicals; it penetrates the blood-brain barrier and, thus, protects the brain and nerve cells. It also reduces platelet aggregation and so counteracts the formation of blood clots or thrombi. The main aim of this review is to summarize the current findings about the positive influence of wine consumption on human organ function, chronic diseases, and the reduction of damage to the cardiovascular system.

Alcohol consumption pattern and risk of Barrett's oesophagus and erosive oesophagitis: an Italian case-control study

Knowledge about the association between alcohol and Barrett's oesophagus and reflux oesophagitis is conflicting. In this case-control study we evaluated the role of specific alcoholic beverages (red and white wine, beer and liquors) in 339 Barrett's oesophagus and 462 oesophagitis patients compared with 619 endoscopic controls with other disorders, recruited in twelve Italian endoscopic units. Data on alcohol and other individual characteristics were obtained from structured questionnaires. No clear, monotonic significant dose-response relationship was pointed out for red wine. However, a generalised U-shaped trend of Barrett's oesophagus/oesophagitis risk due to red wine consumption particularly among current drinkers was found. Similar results were also found for white wine. Liquor/spirit consumption seemed to bring about a 1·14-2·30 risk excess, although statistically non-significant, for current Barrett's oesophagus/oesophagitis drinkers. Statistically significant decreasing dose-response relationships were found in Barrett's oesophagus for frequency and duration of beer consumption. Similar, but less clear downward tendencies were also found for oesophagitis patients. In conclusion, although often not statistically significant, our data suggested a reduced risk of Barrett's oesophagus and oesophagitis with a low/moderate intake of wine and beer consumption. A non-significant increased risk of Barrett's oesophagus/oesophagitis was observed with a higher intake of any type of heavy alcohol consumption, but no conclusion can be drawn owing to the high number of non-spirit drinkers and to the small number of drinkers at higher alcohol intake levels.

Gender difference in gastro-esophageal reflux diseases

The incidence of esophageal adenocarcinoma (EAC) has risen sharply in western countries over the past 4 decades. This type of cancer is considered to follow a transitional process that goes from gastro-esophageal reflux disease (GERD) to Barrett's esophagus (BE, a metaplastic condition of the distal esophagus), a precursor lesion and ultimately adenocarcinoma. This spectrum of GERD is strongly predominant in males due to an unidentified mechanism. Several epidemiologic studies have described that the prevalence of GERD, BE and EAC in women is closely related to reproductive status, which suggests a possible association with the estrogen level. Recently, we revealed in an in vivo study that the inactivation of mast cells by the anti-inflammatory function of estrogen may account for the gender difference in the GERD spectrum. Other studies have described the contribution of female steroid hormones to the gender difference in these diseases. Estrogen is reported to modulate the metabolism of fat, and obesity is a main risk factor of GERDs. Moreover, estrogen could confer esophageal epithelial resistance to causative refluxate. These functions of estrogen might explain the approximately 20-year delay in the incidence of BE and the subsequent development of EAC in women compared to men, and this effect may be responsible for the male predominance. However, some observational studies demonstrated that hormone replacement therapy exerts controversial effects in GERD patients. Nevertheless, the estrogen-related endocrine milieu may prevent disease progression toward carcinogenesis in GERD patients. The development of innovative alternatives to conventional acid suppressors may become possible by clarifying the mechanisms of estrogen.

Alcohol consumption and the risk of Barrett's esophagus: a comprehensive meta-analysis

Several studies have been proposed to investigate the association between alcohol consumption and risk of Barrett’s esophagus (BE), but as of yet, no quantitative summary of the literature to clarify the relationship between them. In our study, twenty eligible cohort studies involving 42925 participants were identified. Combined relative risk (RR) ratios for the highest versus lowest alcohol consumption levels were calculated. The alcohol dose-response analysis was performed to investigate the association between the increment consumption of 10 g/d alcohol and the risk of developing BE. Subgroup analyses were used to examine heterogeneity across the studies. A combined RR of 0.98 (0.62–1.34) was found when comparing highest vs. lowest alcohol consumption levels for BE. An inverse association between alcohol and incidence of BE (RR 0.51; 95% CI: 0.055–0.96) was demonstrated in women. Moreover, Asian drinkers had a relative higher risk of BE (RR 1.34; 95% CI: 1.11–1.56) compared with Western drinkers. In conclusion, our results showed that overall alcohol consumption was not associated with increased BE incidence. The limited data available on alcohol consumption supports a tentative inversion of alcohol consumption with BE risk in women, while Asian drinkers tend to have a higher risk of BE.

Association Between Alcohol Consumption and the Risk of Barrett's Esophagus: A Meta-Analysis of Observational Studies

The association between alcohol consumption and Barrett's esophagus (BE) remained uncertain and controversial in the previous studies. We performed a meta-analysis of observational studies to clarify the association.We searched PubMed, Web of Science, and Embase for studies on alcohol consumption and risk of BE published before February 2015. A total of 20 studies reporting the association between alcohol consumption and the risk of BE were identified. Subgroup analyses, meta-regression analyses, sensitivity analyses, and publication bias tests were also performed. Several results from individual studies were pooled using a dose-response meta-analysis.A total of 20 studies involving 45,181 participants and 4432 patients of BE were included in the meta-analysis. No association was found between alcohol consumption and BE (relative risk [RR] = 1.10, 95% confidence interval [CI] 0.96-1.27, I = 48.60%) in our study. In subgroup analysis, alcohol consumption was associated with an increased risk of BE in men (RR = 1.35, 95% CI 1.13-1.61, I = 0.00%) and Asian population (RR = 1.60, 95% CI 1.03-2.49, I = 60.60%). In beverage-specific consumption analysis, liquor was associated with an increased risk of BE (RR = 1.16, 95% CI 1.02-1.32, I = 0.00%). Multivariate meta-regression analysis suggested that geographic area, and adjusted age, sex, body mass index, and smoke, might explain 70.75% of the heterogeneity between the studies. We also found the inverse association (RR = 0.84, 95% CI 0.72-0.98, I = 0.00%) between alcohol consumption and BE among subjects when compared with population controls.Overall, there was no significant association between alcohol consumption and BE. Alcohol consumption may be a risk factor of BE in men and Asian population, and liquor consumption may also increase the risk of BE. Significant inverse association was observed between alcohol consumption and BE, for comparisons with population controls.

The changing role of the pathologist in the management of Barrett's oesophagus

Pathological specimens from columnar-lined oesophagus (CLO) comprise a considerable proportion of the workload of gastrointestinal pathologists in Western countries. There remain controversies concerning the diagnostic role of pathology. More recently, in the UK at least, the diagnosis has been regarded as primarily an endoscopic endeavour, with pathology being corroborative and only diagnostic when endoscopic features are equivocal or when there are additional features that make the endoscopic diagnosis unclear. There is also recognition that demonstration of intestinalisation or 'goblet cells' is not paramount, and should not be required for the diagnosis. There have been notable changes in the management of CLO neoplasia: pathologists are centrally involved in its management. Pathological assessment of endoscopic mucosal resection (EMR) specimens provides the most useful means of determining the management of early neoplasia and of determining indications for surgery. This represents an extraordinarily rapid change in management, in that, <10 years ago, laborious Seattle-type biopsy protocols were recommended, and high grade dysplasia was an indication for resectional surgery. Now, individual patient management is paramount: multi-professional meetings determine management after biopsy and EMR assessment. One significant change is that major resections are undertaken less often, in Western countries, for CLO neoplasia.

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.

Alcohol consumption and the risk of Barrett’s esophagus: A meta-analysis

AIM: To evaluate the possible association between alcohol consumption and Barrett’s esophagus (BE).

METHODS: We performed a systematic literature search of multiple online electronic databases. Inclusion criteria entailed studies about alcohol and BE. Meta-analysis was conducted to evaluate odds ratio (OR) and 95%CIs for the association between alcohol consumption and BE.

RESULTS: Twenty studies comprising 4758 patients with BE were included in the meta-analysis. The risk of BE in patients with alcohol consumption was increased compared with control groups (OR = 1.01; 95%CI: 1.00-1.02), especially in case-control and cohort, European and Asian, and hospital studies, but there was a decreased risk of BE associated with alcohol consumption from American studies (OR = 0.86; 95%CI: 0.77-0.96). At the same time, there was no significant association between BE and alcohol consumption in community studies (OR = 0.97; 95%CI: 0.84-1.12) and the type of alcohol (wine, beer and liquor) studies.

CONCLUSION: Our meta-analysis found that alcohol consumption was associated with an increased risk of BE, especially for European and Asian drinkers.

Alcohol and the risk of Barrett's esophagus: a pooled analysis from the International BEACON Consortium

OBJECTIVES

Results from studies examining the association between alcohol consumption and the risk of Barrett's esophagus have been inconsistent. We assessed the risk of Barrett's esophagus associated with total and beverage-specific alcohol consumption by pooling individual participant data from five case-control studies participating in the international Barrett's and Esophageal Adenocarcinoma Consortium.

METHODS

For analysis, there were 1,282 population-based controls, 1,418 controls with gastroesophageal reflux disease (GERD), and 1,169 patients with Barrett's esophagus (cases). We estimated study-specific odds ratios (ORs) and 95% confidence intervals (95% CI) using multivariable logistic regression models adjusted for age, sex, body mass index (BMI), education, smoking status, and GERD symptoms. Summary risk estimates were obtained by random-effects models. We also examined potential effect modification by sex, BMI, GERD symptoms, and cigarette smoking.

RESULTS

For comparisons with population-based controls, although there was a borderline statistically significant inverse association between any alcohol consumption and the risk of Barrett's esophagus (any vs. none, summary OR=0.77, 95% CI=0.60-1.00), risk did not decrease in a dose-response manner (Ptrend=0.72). Among alcohol types, wine was associated with a moderately reduced risk of Barrett's esophagus (any vs. none, OR=0.71, 95% CI=0.52-0.98); however, there was no consistent dose-response relationship (Ptrend=0.21). We found no association with alcohol consumption when cases were compared with GERD controls. Similar associations were observed across all strata of BMI, GERD symptoms, and cigarette smoking.

CONCLUSIONS

Consistent with findings for esophageal adenocarcinoma, we found no evidence that alcohol consumption increases the risk of Barrett's esophagus.

Health behaviours and potentially preventable hospitalisation: a prospective study of older Australian adults

Objective

Several studies have demonstrated the effects of health behaviours on risk of chronic diseases and mortality, but none have investigated their contribution to potentially preventable hospitalisation (PPH). We aimed to quantify the effects on risk of PPH of six health behaviours: smoking; alcohol consumption; physical activity; fruit and vegetables consumption; sitting time; and sleeping time.

Design/Setting

Prospective observational study in New South Wales, Australia.

Subjects

267,006 men and women aged 45 years and over.

Outcome Measures

PPH admissions and mortality during follow-up according to individual positive health behaviours (non-smoking, <14 alcoholic drinks per week, ≥2.5 hours of physical activity per week, ≥2 servings of fruit and 5 servings of vegetables per day, <8 hours sitting and ≥7 hours sleeping per day) and the total number of these behaviours.

Results

During an average of 3 years follow-up, 20971 (8%) participants had at least one PPH admission. After adjusting for potential confounders, participants who reported all six positive health behaviours at baseline had 46% lower risk of PPH admission (95% CI 0.48–0.61), compared to those who reported having only one of these behaviours. Based on these risk estimates, approximately 29% of PPH admissions in Australians aged 45 years and over were attributable to not adhering to the six health behaviours. Estimates were similar for acute, chronic and vaccine-preventable categories of PPH admissions.

Conclusions

Individual and combined positive health behaviours were associated with lower risk of PPH admission. These findings suggest that there is a significant opportunity to reduce PPH by promoting healthy behaviours.

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.

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.

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.

Review: Experimental models for Barrett's esophagus and esophageal adenocarcinoma

Several different cell culture systems and laboratory animal models have been used over the years to study Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Most of the existing models have key differences with the human esophagus and complex pathogenesis of disease. None of the models offers an ideal system for the complex study of environmental exposure, genetic risk, and prevention strategies. In fact, different model systems may be required to answer different specific research questions about the pathogenesis of BE and EAC. Given the high mortality associated with EAC and the fact that current screening strategies miss most cases of EAC, advances in basic and translational science related to esophageal injury, repair, and carcinogenesis are clearly needed. This review describes several of the existing and potential model systems for BE and EAC with their benefits and disadvantages.

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.