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

Causal association between dietary factors and esophageal diseases: A Mendelian randomization study

BACKGROUND

Using Mendelian randomization (MR) approach, our objective was to determine whether there was a causal association between dietary factors and gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), or esophageal cancer (EC).

METHODS

Genome-wide association study (GWAS) data for eighteen types of dietary intake were obtained from the UK Biobank. GWAS data for GERD, BE, and EC were sourced from the FinnGen consortium. We performed univariable and multivariable MR analysis to assess the cause effect between dietary factors and esophageal diseases. MR results were expressed as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Raw vegetable intake was associated with a lower risk of GERD (OR = 0.478; P = 0.011). On the contrary, cooked vegetable intake increased the risk of GERD (OR = 1.911; P = 0.024). Bread intake was associated with increased odds of BE (OR = 6.754; P = 0.007), while processed meat intake was associated with reduced risk of BE (OR = 0.210; P = 0.035). We also observed evidence that increased consumption of dried fruit (OR = 0.087; P = 0.022) and salt added to food (OR = 0.346; P = 0.045) could prevent EC. The results of multivariable MR showed that the protective effect of consumption of salt added to food on EC was no longer significant after adjusting for the consumption of dried fruit.

CONCLUSION

Vegetable consumption was associated with GERD, whereas consumption of bread and processed meat was associated with BE. Dried fruit intake was associated with a lower risk of EC, and the protective effect of consumption of salt added food on EC may also be mediated by consumption of dried fruit. Future research should be performed to investigate the mechanisms behind these cause-and-effect relationships to reduce the burden of disease caused by dietary habits.

Risk factors for Barrett's esophagus: Recent advances

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

Outcomes of 325 one anastomosis gastric bypass operations: an Australian case series

BACKGROUND

The One Anastomosis Gastric Bypass (OAGB) is a relatively novel procedure. Studies have demonstrated that it is at least as effective as other bariatric procedures but with fewer major complications and shorter operating time, yet OAGB is performed less partially due to a paucity of supportive evidence. We report the outcomes of a prospectively maintained database of patients undergoing laparoscopic OAGB.

METHODS

All OAGB procedures performed by two surgeons across two hospitals from 2016 to 2019 were recorded in a prospectively maintained database. Patients with at least 1 year of follow up were included in this study and missing data was obtained from patient records. The primary outcome was percentage excess weight loss (EWL). The secondary outcome was surgical complication rate.

RESULTS

Three hundred and twenty-five patients with a mean pre-operative body mass index of 43.3 kg/m² were included. The majority (85.2%) had a biliopancreatic limb length of 150 cm. The median EWL was 74.2% and 79.4% of patients achieved at least 50% EWL. There were no deaths, the overall re-operation rate was 4.9% and 1.9% of patients developed stomal ulcers. Seven patients went on to have a Roux-en-Y conversion predominantly for symptomatic reflux.

CONCLUSION

OAGB leads to excellent weight loss and is at least as safe as more commonly performed procedures, it may be a suitable treatment for a greater number of patients than it is being offered to at present.

Demographic and lifestyle risk factors for gastroesophageal reflux disease and Barrett's esophagus in Australia

We examined demographic and lifestyle risk factors for incidence of gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE) in an Australian cohort of 20,975 participants aged 40-63 at recruitment (1990-1994). Information on GERD and BE was collected between 2007 and 2010. GERD symptoms were defined as self-reported heartburn or acid regurgitation. BE was defined as endoscopically confirmed columnar-lined esophagus. Risk factors for developing GERD symptoms, BE diagnosis, age at symptom onset, and age at BE diagnosis were quantified using regression. During a mean follow-up of 15.8 years, risk of GERD symptoms was 7.5% (n = 1,318) for daily, 7.5% (n = 1,333) for 2-6 days/week, and 4.3% (n = 751) for 1 day/week. There were 210 (1.0%) endoscopically diagnosed BE cases, of whom 141 had histologically confirmed esophageal intestinal metaplasia. Female sex, younger age, lower socioeconomic position (SEP) and educational attainment, and former smoking were associated with higher GERD risk. Male sex and smoking were associated with earlier GERD symptom onset. Men, older participants, those with higher SEP, and former smokers were at higher BE risk. There was some evidence higher SEP was associated with earlier BE diagnosis. GERD and BE had different demographic risk factors but shared similar lifestyle factors. Earlier GERD symptom onset for men and smokers might have contributed to higher BE risk. The SEP patterns observed for GERD and BE suggest potential inequity in access to care. These findings would be important in the development of clinical risk prediction models for early detection of BE.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

The Nissen-Sleeve (N-Sleeve): Results of a Cohort Study

BACKGROUND

The Montpellier bariatric team has recently proposed some technical alternatives to decrease the rate of gastroesophageal reflux disease (GERD) after bariatric surgery and also to offer patients an alternative in case of contraindication to Roux-en-Y gastric bypass (RYGBP): the Nissen-Sleeve (N-Sleeve).

OBJECTIVES

We present here the results from a cohort of patients that underwent an operation with this newly designed anti-reflux bariatric procedure N-Sleeve: Nissen valve added to a standard SG.

METHODS

Data from a prospective, observational, and monocentric cohort. All consecutive patients presenting to the bariatric surgery department for a laparoscopic sleeve gastrectomy between 2016 and 2018 with GERD were included in the study. The fundus was stapled with a margin from the valve, and the valve was created with tissue at a distance from the greater curvature so as to avoid a double layer stapling of the stomach.

RESULTS

A total of 70 patients were included in the study. Ninety percent of the cohort presented with a hiatal hernia at the time of surgery. No mortality was observed during the follow-up period. Concerning GERD, 76% of all patients had preoperative esophageal syndromes, whereas 21% were asymptomatic with associated esophagitis. Grade A-C esophagitis was present in 99% of the cohort, but no Barrett's esophagus was present. Fifty-six (80%) patients used PPIs regularly. At 1 year of follow-up, one patient was still symptomatic.

CONCLUSIONS

Comparative trials remain necessary between N-Sleeve and standard bariatric procedures to refine the specific indications of each of them and determine the eventual role of the N-Sleeve.

Radio-induced esophageal motility disorders: An unrecognized diagnosis

PURPOSE

Esophageal motility disorders (EMD) after cervical or thoracic radiation therapy (RT) may represent a late impairment and appear under-diagnosed. This study aimed to assess the prevalence of EMD, diagnosed by high-resolution esophageal manometry (HREM) after cervical or thoracic RT. In this retrospective, single-centre study, all patients whom received cervical or thoracic RT and underwent HREM were eligible.

MATERIAL AND METHODS

Oncologic data were collected: site of neoplasia, type of cancer, oncologic management (surgery and chemotherapy). EMD were classified according to the new Chicago Classification.

RESULTS

Twenty patients (14 females), of mean age 62.33±11.14 years were included. Breast cancer was the most represented indication for RT (40%). Other cancers were lung tumor, head and neck tumors and Hogdkin's lymphoma. Dysphagia was the most frequent symptom justifying HREM (70%). Patients received a mean of 51±19.27 Gy, 70% of them (14/20) had radiation therapy concomitantly with chemotherapy. The delay between last radiation therapy session and HERM was 10.68±12.42 years. Twelve (60%) patients had an abnormal pattern at on HERM. Among them, 3 patients (15%) presented with a major motility disorder. The most frequent motility disorder was ineffective esophageal motility in 8 (40%) patients, 1 (5%) patient presented with type II achalasia.

CONCLUSION

EMD should be suspected in patients with a history of cervical or thoracic RT in case of upper GI symptoms with normal endoscopy. In these particular patients, a manometric diagnosis that can explain their symptoms is of particular importance to limit anxiety linked to unexplained troubles.

Long-term endoscopic follow-up after sleeve gastrectomy

BACKGROUND

Endoscopic follow-up after sleeve gastrectomy (SG) sometime reveals worrisome findings as the presence of major digestive lesions such as esophagitis, Barrett's esophagus (BE), and also esophageal cancer.

OBJECTIVES

The aim of this study was to investigate the frequency and severity of esophageal and gastric lesions after SG.

METHODS

Our team collected the results of esogastric endoscopies performed on patients who underwent SG up to five years before in our hospital, from April 2010 to August 2014. Summons were sent by mail to all patients operated on between those dates. The results were collected from January 2018 to June 2019.

RESULTS

Of the 765 patients who underwent SG up to five years before, only 78 (10.2%) agreed to undergo an upper digestive endoscopy. The average age before surgery was 51 years (range: 25-70 years). The mean preoperative body mass index (BMI) was 44.2±4.6kg/m². For 12 out of these 78 patients (15.4%) it was revisional surgery: 9 SG after gastric banding, and 3 revisional SG (Re-SG). With an average follow-up of 6.3±0.8 years, the endoscopic results of the 78 patients were found to be normal in 31 cases (39.7%): gastritis was found in 28 patients (35.9%), severe grade C or D esophagitis was found in 15 cases (19.2%), hiatal hernia in 18 cases (23.1%), a benign gastric polyp in 2 cases (2.6%). Of the 28 patients with gastritis, HelicobacterPylori was detected in 8 cases (28.6%). No cancer was diagnosed, and BE after SG was found in only one case (1.3%) (normal before surgery). Six of 15 patients with esophagitis (40%) had reflux symptoms. Fourteen of these patients (93.3%) developed de novo esophagitis.

CONCLUSION

Only 10.2% of operated patients agreed to a long-term esogastric endoscopy. The frequency and severity of endoscopic anomalies observed with an average follow-up of more than 6 years pleads for a policy of systematic upper endoscopies of long-term control after SG.

Development and validation of a risk prediction model to diagnose Barrett's oesophagus (MARK-BE): a case-control machine learning approach

Background

Screening for Barrett's Oesophagus (BE) relies on endoscopy which is invasive and has a low yield. This study aimed to develop and externally validate a simple symptom and risk-factor questionnaire to screen for patients with BE.

Methods

Questionnaires from 1299 patients in the BEST2 case-controlled study were analysed: 880 had BE including 40 with invasive oesophageal adenocarcinoma (OAC) and 419 were controls. This was randomly split into a training cohort of 776 patients and an internal validation cohort of 523 patients. External validation included 398 patients from the BOOST case-controlled study: 198 with BE (23 with OAC) and 200 controls. Identification of independently important diagnostic features was undertaken using machine learning techniques information gain (IG) and correlation based feature selection (CFS). Multiple classification tools were assessed to create a multi-variable risk prediction model. Internal validation was followed by external validation in the independent dataset.

Findings

The BEST2 study included 40 features. Of these, 24 added IG but following CFS, only 8 demonstrated independent diagnostic value including age, gender, smoking, waist circumference, frequency of stomach pain, duration of heartburn and acid taste and taking of acid suppression medicines. Logistic regression offered the highest prediction quality with AUC (area under the receiver operator curve) of 0.87. In the internal validation set, AUC was 0.86. In the BOOST external validation set, AUC was 0.81.

Interpretation

The diagnostic model offers valid predictions of diagnosis of BE in patients with symptomatic gastroesophageal reflux, assisting in identifying who should go forward to invasive testing. Overweight men who have been taking stomach medicines for a long time may merit particular consideration for further testing. The risk prediction tool is quick and simple to administer but will need further calibration and validation in a prospective study in primary care.

Funding

Charles Wolfson Trust and Guts UK.

Prevalence and risk factors for Barrett’s esophagus in Taiwan

BACKGROUND

Barrett’s esophagus (BE) is a pre-malignant condition associated with the development of esophageal adenocarcinoma. The prevalence of BE in the general populations of Asian countries ranges from 0.06% to 1%. However, with lifestyle changes in Asian countries and adoption of western customs, the prevalence of BE might have increased.

AIM

To determine the current prevalence of BE in Taiwan, and to investigate risk factors predicting the presence of BE.

METHODS

This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan. Between January 2015 and December 2015, 3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included. Patient characteristics and endoscopic findings were carefully reviewed. Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia (ESEM). BE was defined based on extension of the columnar epithelium ≥ 1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia (IM) in the metaplastic esophageal epithelium. Clinical factors of subjects with BE and subjects without BE were compared, and the risk factors predicting BE were analyzed.

RESULTS

A total of 3385 subjects (mean age, 51.29 ± 11.42 years; 57.1% male) were included in the study, and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination. The majority of these individuals were classified as short segment BE (n = 85). The overall prevalence of BE was 2.6%. Multivariate analysis disclosed that old age [odds ratio (OR) = 1.033; 95% confidence interval (CI): 1.012-1.055; P = 0.002], male gender (OR = 2.106; 95%CI: 1.145-3.872; P = 0.017), ingestion of tea (OR = 1.695; 95%CI: 1.043-2.754; P = 0.033), and presence of hiatal hernia (OR = 3.037; 95%CI: 1.765-5.225; P < 0.001) were significant risk factors predicting BE. The independent risk factor for the presence of IM in ESEM lesions was old age alone (OR = 1.029; 95%CI: 1.006-1.053; P = 0.014).

CONCLUSION

Current prevalence of BE among the general population in Taiwan is 2.6%. Old age, male gender, ingestion of tea and hiatal hernia are significant risk factors for BE.

Systematic Endoscopy 5 Years After Sleeve Gastrectomy Results in a High Rate of Barrett's Esophagus: Results of a Multicenter Study

BACKGROUND

Recent evidence has indicated an increased risk of Barrett's esophagus (BE) in the long term after sleeve gastrectomy (SG).

AIM

The aim of the study is to investigate the spectrum of gastroesophageal reflux disease (GERD) symptoms as well as the prevalence of BE, at minimum 5 years after SG in patients who underwent SG in different bariatric centers of two countries: France and Italy.

PATIENTS AND METHODS

Five high volume outpatient centers dedicated to bariatric surgery that routinely perform upper GI endoscopy before any bariatric procedures were invited to participate in the study. From January 2017 to June 2018, each center during scheduled postoperative evaluation after surgery asked a minimum 10 consecutive patients, which had performed SG at least 5 years before and with no evidence of BE preoperatively, to undergo another upper GI endoscopy.

RESULTS

Ninety (66 F) consecutive patients were enrolled. The mean follow-up was 78 ± 15 months, and the mean total body weight loss was 25 ± 12%. The prevalence of BE was 18.8% with no significant difference among centers. Weight loss failure was significantly associated with BE (p < 0.01). The prevalence of GERD symptoms, erosive esophagitis, and the usage of PPIs increased from 22%, 10%, and 22% before the SG to 76%, 41%, and 52% at the time of follow-up, respectively (p < 0.05).

CONCLUSIONS

This multicenter study show a high rate of BE at least 5 years after SG. Weight loss failure was significantly associated with BE. We suggest to provide systematic endoscopy in these patients to rule out this condition.

A phase I pilot study evaluating the beneficial effects of black raspberries in patients with Barrett's esophagus

Black raspberries inhibit a broad range of cancers in preclinical models which has led to clinical evaluations targeting premalignant lesions of the colon, oral cavity and esophagus. A phase I pilot study was conducted in twenty Barrett's esophagus (BE) patients to investigate the effect of lyophilized black raspberries (LBR) on urinary metabolites and markers of lipid peroxidation, DNA damage and tissue markers of cellular proliferation, detoxification, and inflammation. Surveys, biopsies, blood and urine samples were collected before and after 6 months of LBR treatment (32 or 45 g). LBR significantly reduced urinary excretion of 8-epi-prostaglandin F2α, a marker of lipid peroxidation linked to oxidative stress and free radical damage. Urinary levels of the ellagitannin metabolites, urolithin A-glucuronide, urolithin A-sulfate and dimethylellagic acid glucuronide were significantly increased following 12 and 26 weeks of LBR consumption and may prove useful as indicators of compliance in future clinical studies. Immunohistochemical staining of BE biopsies following LBR treatment showed significant increases in mean GST-pi levels, with 55.6% of subjects responding favorably. In summary, LBR significantly decreased urinary lipid peroxidation levels and significantly increased GST-pi, a marker of detoxification, in BE epithelium. Still, LBR may need to be formulated differently, administered at higher concentrations or multiple times a day to increase efficacy.

Esophageal Motor Disorders Are a Strong and Independant Associated Factor of Barrett's Esophagus

Background/Aims

Esophageal motor disorder (EMD) has been shown to be associated with gastroesophageal reflux disease (GERD). However, the association of EMD with a Barrett's esophagus (BE) is controversial. Our objective was to evaluate whether the presence of EMD was an independent factor associated with BE.

Methods

A retrospective case-control study was conducted in GERD patients who all had oeso-gastroduodenal endoscopy and high-resolution esophageal manometry. The clinical data collected was known or potential risk factors for BE: male gender, smoking and alcohol consumption, age, body mass index, presence of hiatal hernia, frequency, and age of GERD. EMD were classified according to the Chicago classification into: ineffective motor syndrome, fragmented peristalsis and absence of peristalsis, lower esophageal sphincter hypotonia.

Results

Two hundred and one patients (101 in the GERD + BE group and 100 in the GERD without BE) were included. In univariate analysis, male gender, alcohol consumption, presence of hiatal hernia, and EMD appeared to be associated with the presence of BE. In a multivariate analysis, 3 independent factors were identified: the presence of EMD (odds ratio [OR], 3.99; 95% confidence interval [CI], 1.71-9.28; P = 0.001), the presence of hiatal hernia (OR, 5.60; 95% CI, 2.45-12.76; P ＜ 0.001), Helicobacter pylori infection (OR, 0.08; 95% CI, 0.01-0.84; P = 0.035).

Conclusions

The presence of EMD (particularly ineffective motor syndrome and lower esophageal sphincter hypotonia) is a strong independent associated factor of BE. Searching systematically for an EMD in patients suffering from GERD could be a new strategy to organize the endoscopic follow-up.

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.

Risk factors for Barrett's esophagus

Barrett's esophagus (BE) is a well-recognized precursor of esophageal adenocarcinoma (EAC) and is defined as ≥1 cm segment of salmon-colored mucosa extending above the gastroesophageal junction into the tubular esophagus with biopsy confirmation of metaplastic replacement of the normal squamous epithelium by intestinal-type columnar epithelium. The incidence of both BE and EAC has been increasing over the past few decades. As a result, preventing the development of BE by identifying and understanding its modifiable and non-modifiable risk factors may help reduce the incidence of EAC. Over the recent past, a tremendous amount of progress has been made towards improving our knowledge of risk factors and pathogenesis of BE. This article reviews the evidence for the various risk factors for developing BE.

Alcohol consumption and corresponding factors: A novel perspective on the risk factors of esophageal cancer

Esophageal cancer is the eighth most common type of cancer in the world, and the sixth most common cause of mortality from cancer. Alcohol consumption is the major risk factor for esophageal cancer, due to the worldwide prevalence and high carcinogenicity of the ethanol metabolite. In epidemiological studies, the efficiency of alcohol intake to enhance the risk of esophageal cancer is altered by daily ethanol consumption, type of alcoholic beverages ingested, time since quitting drinking, age of drinking initiation, differences in population and subtypes of esophageal cancer. Corresponding factors, including gene polymorphisms, tobacco smoking, oral microorganisms and folate deficiency, reveal a synergistic effect in concurrent alcohol users that may lead to an increased risk of developing esophageal cancer. Consequently, esophageal cancer prevention involves multiple aspects, including quitting drinking and smoking, maintaining an adequate oral health and ingesting adequate quantities of folate, particularly in genetically high-risk populations.

The impact of lifestyle on Barrett's Esophagus: A precursor to esophageal adenocarcinoma

BACKGROUND

Barrett's Esophagus (BE), particularly long-segment Barrett's Esophagus, and the age of onset of Barrett's Esophagus are risk factors for esophageal adenocarcinoma. However, it is unknown if lifestyle factors such as alcohol abuse, tobacco use, weight gains that increase the risk of developing BE and esophageal adenocarcinoma affect its length or age at diagnosis.

METHODS

In a retrospective, cross-sectional analysis, we analyzed 158 newly diagnosed adult BE patients at a 600-bed tertiary care center in the United States from 1999 to 2008. We constructed generalized linear models for the outcomes of BE length and age at diagnosis. Predictors of interest included current or prior alcohol abuse, tobacco use, weight gain over the last 5 years, and body mass index (BMI).

RESULTS

71 (45%) had length ≥ 3 cm. Barrett's Esophagus length was positively correlated with hiatal hernia length (r=0.67, p<0.001) and heartburn duration (r=0.36, p<0.001). Multivariate results showed no significant relationship between alcohol abuse, tobacco use, weight gain or BMI and BE length. Patients with weight gain, current tobacco use, and male gender were diagnosed at a significantly younger age than their peers (for example, the adjusted mean age at diagnosis for current tobacco users vs. non-smokers was 49.2 years vs. 54.7 years, p=0.029).

CONCLUSIONS

Lifestyle factors did not appear to affect Barrett's Esophagus length but weight gains, smoking, and male gender were associated with a diagnosis at a significantly younger age.

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.

Inhibition of tumor energy pathways for targeted esophagus cancer therapy

Interest in targeting cancer metabolism has been renewed in recent years with the discovery that many cancer related pathways have a profound effect on metabolism and that many tumors become dependent on specific metabolic processes. Accelerated glucose uptake during anaerobic glycolysis and loss of regulation between glycolytic metabolism and respiration, are the major metabolic changes found in malignant cells. The non-metabolizable glucose analog, 2-deoxy-D-glucose inhibits glucose synthesis and adenosine triphosphate production. The adenosine monophosphate-activated protein kinase (AMPK) is a key sensor of cellular energy and AMPK is a potential target for cancer prevention and/or treatment. Metformin is an activator of AMPK which inhibits protein synthesis and gluconeogenesis during cellular stress. This article reviews the status of clinical and laboratory researches exploring targeted therapies via metabolic pathways for treatment of esophageal cancer.

A newly identified susceptibility locus near FOXP1 modifies the association of gastroesophageal reflux with Barrett's esophagus

BACKGROUND

Important risk factors for esophageal adenocarcinoma and its precursor, Barrett's esophagus, include gastroesophageal reflux disease, obesity, and cigarette smoking. Recently, genome-wide association studies have identified seven germline single-nucleotide polymorphisms (SNP) that are associated with risk of Barrett's esophagus and esophageal adenocarcinoma. Whether these genetic susceptibility loci modify previously identified exposure-disease associations is unclear.

METHODS

We analyzed exposure and genotype data from the BEACON Consortium discovery phase GWAS, which included 1,516 esophageal adenocarcinoma case patients, 2,416 Barrett's esophagus case patients, and 2,187 control participants. We examined the seven newly identified susceptibility SNPs for interactions with body mass index, smoking status, and report of weekly heartburn or reflux. Logistic regression models were used to estimate ORs for these risk factors stratified by SNP genotype, separately for Barrett's esophagus and esophageal adenocarcinoma.

RESULTS

The odds ratio for Barrett's esophagus associated with at least weekly heartburn or reflux varied significantly with the presence of at least one minor allele of rs2687201 (nominal P = 0.0005, FDR = 0.042). ORs (95% CIs) for weekly heartburn or reflux among participants with 0, 1, or 2 minor alleles of rs2687201 were 6.17 (4.91-7.56), 3.56 (2.85-4.44), and 3.97 (2.47-6.37), respectively. No statistically significant interactions were observed for smoking status and body mass index.

CONCLUSION

Reflux symptoms are more strongly associated with Barrett's esophagus risk among persons homozygous for the major allele of rs2687201, which lies approximately 75 kb downstream of the transcription factor gene FOXP1.

IMPACT

The novel gene-exposure interaction discovered in this study provides new insights into the etiology of esophageal adenocarcinoma.

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.

Association between the body mass index and the risk of Barrett's esophagus in Japan

BACKGROUND

We investigated the association between long-segment Barrett's esophagus and obesity in the Japanese population in a multicenter case-control trial.

METHODS

One hundred thirteen patients with endoscopically detected Barrett's esophagus with a length of more than 2 cm and the same number of sex- and age-matched controls were prospectively enrolled. Barrett's esophagus was diagnosed based on the Prague C and M criteria. The body mass index (BMI) of the subjects was categorized into the following groups: normal, BMI <22.9; overweight, BMI 23.0-24.9, and obese, BMI >25.0. To determine the association between BMI and the risk of Barrett's esophagus, multivariate logistic regression analyses were performed.

RESULTS

The basically adjusted regression model adjusted for smoking and alcohol consumption revealed that overweight and obesity were significantly associated with an elevated risk of Barrett's esophagus (OR 2.4, 95% CI 1.2-4.7, and OR 2.5, 95% CI 1.3-4.6, respectively). The intensity of the association was not attenuated even after adjustment for gastroesophageal reflux disease-related parameters.

CONCLUSIONS

An increased BMI was associated with an increased risk for Barrett's esophagus through a gastroesophageal reflux-independent mechanism in the Japanese population. Further, unlike in Caucasian populations, being even slightly overweight with a BMI of 23.0-24.9 was an independent risk factor in the Japanese population.

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.

Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC), a disease with increasing burden in the Western world, especially in white men. Risk factors for BE include obesity, tobacco smoking, and gastroesophageal reflux disease (GERD). EAC is the most common form of esophageal cancer in the United States. Risk factors include GERD, tobacco smoking, and obesity, whereas nonsteroidal antiinflammatory drugs and statins may be protective. Factors predicting progression from nondysplastic BE to EAC include dysplastic changes on esophageal histology and length of the involved BE segment. Biomarkers have shown promise, but none are approved for clinical use.

Time distribution of recurrence risk of oesophageal squamous cell carcinoma with complete resection (R0) in a Chinese population

OBJECTIVES

We aimed to clarify the correlation between clinic-pathological characteristics and the distribution of recurrence probability during follow-up of oesophageal squamous cell carcinoma (OSCC) patients with complete resection analysis by hazard function, and to try to provide evidence-based data for optimal timing for adjuvant therapy.

METHODS

A single-institution, retrospective study was conducted on 553 Chinese patients with OSCC who underwent R0 resection between January 2005 and October 2007. Survival curves were generated using the Kaplan-Meier method, and hazard function was used to analyse the annual recurrence hazard.

RESULTS

The median recurrence-free survival time of these patients was 3.4 years. In univariate analysis, the favourable prognostic factors were gender, smoking status, a tumour length of ≤4.0 cm, tumour invasion thickness, normal level of squamous cell carcinoma (SCC) antigen, pathological T category and pathological N category. In multivariate analysis, pathological T category and pathological N category were independent prognostic factors. Overall, the recurrence hazard curve for the entire cohort showed that the first major recurrence surge began to increase from the first year at 22.97% and peaked at 1.3 years at 27.4% during follow-up. The second recurrence surge peaked during the seventh year at 13.0%. A lower recurrence risk was observed in patients with the following clinic-pathological characteristics: gender, smoking status and N0.

CONCLUSIONS

We identify the presence of two peaks for recurrence risk in Chinese patients with resectable OSCC, which might contribute to choosing the optimal timing for adjuvant therapy after an operation to decrease or delay the recurrence hazard for patients with resectable OSCC.

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.

The relationship between length of Barrett's oesophagus mucosa and body mass index

BACKGROUND

Length of Barrett's oesophagus (BE) is a risk factor for oesophageal cancer. The underlying mechanisms that determine BE length are nor fully known.

AIM

To determine if there is a correlation between obesity and length of BE.

METHODS

Using a population-based study, 381 patients diagnosed with Barrett's oesophagus between 1999 and 2013 were included. Body mass index (BMI) at the time of BE diagnosis was calculated. Upper endoscopy reports were reviewed to obtain the length of BE. Spearman's correlation coefficient was performed to assess the strength of the relationship between Barrett's length and BMI. A multivariate logistic regression analysis was conducted to further examine the association between BMI and length of BE.

RESULTS

The adjusted odds ratio for each five-point increase in BMI was 1.5 (95% CI 1.24-1.81, P < 0.001). The mean BMI was significantly higher in patients with long segment BE as compared to patients with short segment BE (32.7 vs. 30.3, P = 0.001). There was also a positive trend in long segment BE as patients entered into higher BMI categories (Z = 4.25, P < 0.001). There was a significant correlation between BMI and length of BE (r = 0.25, P < 0.0001).

CONCLUSION

The study demonstrated a correlation between BMI and the length of Barrett's oesophagus mucosa. Thus, increased BMI is associated with longer segment of Barrett's oesophagus.

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.

Pathophysiological mechanisms linking obesity and esophageal adenocarcinoma

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

The role of obesity in oesophageal cancer development

The incidence of oesophageal adenocarcinoma has increased dramatically in the developed world in the last half century. Over approximately the same period there has been an increase in the prevalence of obesity. Multiple epidemiological studies and meta-analyses have confirmed that obesity, especially abdominal, visceral obesity, is a risk factor for gastro-oesophageal reflux, Barrett's oesophagus and oesophageal adenocarcinoma. Although visceral obesity enhances gastro-oesophageal reflux, the available data also show that visceral obesity increases the risk of Barrett's oesophagus and adenocarcinoma via reflux-independent mechanisms. Several possible mechanisms could link obesity with the risk of oesophageal adenocarcinoma in addition to mechanical effects increasing reflux. These include reduced gastric Helicobacter pylori infection, altered intestinal microbiome, factors related to lifestyle, the metabolic syndrome and associated low-grade inflammation induced by obesity and the secretion of mediators by adipocytes which may directly influence the oesophageal epithelium. Of these adipocyte-derived mediators, increased leptin levels have been independently associated with progression to oesophageal adenocarcinoma and in laboratory studies leptin enhances malignant behaviours in cell lines. Adiponectin is also secreted by adipocytes and levels decline with obesity: decreased serum adiponectin levels are associated with malignant progression in Barrett's oesophagus and experimentally adiponectin exerts anticancer effects in Barrett's cell lines and inhibits growth factor signalling. At present there are no proven chemopreventative interventions that may reduce the incidence of obesity-associated oesophageal cancer: observational studies suggest that the combined use of a statin and aspirin or another cyclo-oxygenase inhibitor is associated with a significantly reduced cancer incidence in patients with 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.

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.

Body mass index, smoking, and alcohol and risks of Barrett's esophagus and esophageal adenocarcinoma: a UK prospective cohort study

BACKGROUND

The timing of the risk factors cigarette smoking, alcohol and obesity in the development of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) is unclear.

AIMS

To investigate these exposures in the aetiology of BE and EAC in the same population.

METHODS

The cohort included 24,068 men and women, aged 39-79 years, recruited between 1993 and 1997 into the prospective EPIC-Norfolk Study who provided information on anthropometry, smoking and alcohol intake. The cohort was monitored until December 2008 and incident cases identified.

RESULTS

One hundred and four participants were diagnosed with BE and 66 with EAC. A body mass index (BMI) above 23 kg/m(2) was associated with a greater risk of BE [BMI ≥23 vs. 18.5 to <23, hazard ratio (HR) 3.73, 95 % CI 1.37-10.16], and within a normal BMI, the risk was greater in the higher category (HR 3.76, 95 % CI 1.30-10.85, BMI 23-25 vs. 18.5 to >23 kg/m(2)). Neither smoking nor alcohol intake were associated with risk for BE. For EAC, all BMI categories were associated with risk, although statistically significant for only the highest (BMI >35 vs. BMI 18.5 to <23, HR 4.95, 95 % CI 1.11-22.17). The risk was greater in the higher category of a normal BMI (HR 2.73, 95 % CI 0.93-8.00, p = 0.07, BMI 23-25 vs. 18.5 to >23 kg/m(2)). There was an inverse association with ≥7 units alcohol/week (HR 0.51, 95 % CI 0.29-0.88) and with wine (HR 0.49, 95 % CI 0.23-1.04, p = 0.06, drinkers vs. non-drinkers).

CONCLUSIONS

Obesity may be involved early in carcinogenesis and the association with EAC and wine should be explored. The data have implications for aetiological investigations and prevention strategies.

Vegetable, fruit and nitrate intake in relation to the risk of Barrett's oesophagus in a large Dutch cohort

There are few epidemiological data on the dietary risk factors of Barrett's oesophagus, a precursor of oesophageal adenocarcinoma. The present study investigated the association between vegetable, fruit and nitrate intake and Barrett's oesophagus risk in a large prospective cohort. The Netherlands Cohort Study recruited 120,852 individuals aged 55-69 years in 1986. Vegetable and fruit intake was assessed using a 150-item FFQ, and nitrate intake from dietary sources and drinking water was determined. After 16.3 years of follow-up, 433 cases (241 men and 192 women) of Barrett's oesophagus with specialised intestinal metaplasia and 3717 subcohort members were analysed in a case-cohort design using Cox proportional hazards models while adjusting for potential confounders. Men exhibited a lower risk of Barrett's oesophagus in the highest v. the lowest quintile of total (multivariable-adjusted hazard ratio (HR): 0.66, 95% CI 0.43, 1.01), raw (HR 0.63, 95% CI 0.40, 0.99), raw leafy (HR 0.55, 95% CI 0.36, 0.86) and Brassica (HR 0.64, 95% CI 0.41, 1.00) vegetable intake. No association was found for other vegetable groups and fruits. No significant associations were found between vegetable and fruit intake and Barrett's oesophagus risk among women. Total nitrate intake was inversely associated with Barrett's disease risk in men (HR 0.50, 95% CI 0.25, 0.99) and positively associated with it in women (HR 3.77, 95% CI 1.68, 8.45) (P for interaction = 0.04). These results suggest that vegetable intake may contribute to the prevention of Barrett's oesophagus. The possible differential effect in men and women should be evaluated further.

Systematic review with meta-analysis: race-specific effects of alcohol and tobacco on the risk of oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma (OSCC) is associated with alcohol use, tobacco use and African or Asian descent. However, little is known about how racial background modifies the effects of alcohol or tobacco.

AIM

To investigate how racial and geographical background modifies the effect of alcohol and tobacco on OSCC via a systematic review and meta-analysis of published literature.

METHODS

We performed a literature search in multiple online databases regardless of language. Eligible studies were population-based assessments of the effect of tobacco and/or alcohol on the risk of OSCC allowing stratification by race. The quality of studies was assessed by the Newcastle-Ottawa Scale. Meta-analyses were performed to estimate summary effects using random effect models.

RESULTS

Systematic review identified 9668 unique citations of which 34 were eligible. The majority were of high quality. The effect of current smoking vs. never-smoking was weaker among Asians than among Europeans [European: odds ratio (OR) = 4.21, 95% confidence interval (CI) 3.13, 5.66; Asian: OR = 2.31, 95% CI 1.78, 2.99], with the 95% CIs not crossing, indicating statistical significance. Asians also trended towards weaker effects of long-duration cigarette use and of heavy daily cigarette use. There was no difference in the effect of alcohol on OSCC risk by race.

CONCLUSIONS

Contrary to our hypothesis, a weaker effect of tobacco for OSCC was observed among Asians than among Europeans. Differences in other factors must explain the higher incidence of OSCC among Asians. More studies are needed to understand the cause of the disparate incidence of OSCC between races.

Association between markers of obesity and progression from Barrett's esophagus to esophageal adenocarcinoma

BACKGROUND & AIMS

Individuals with Barrett's esophagus (BE) have an increased risk of developing esophageal adenocarcinoma (EA). Obesity contributes to the development of BE and its progression to cancer. We investigated the roles of obesity-induced hyperinsulinemia and dysregulation of adipokines in these processes.

METHODS

We measured fasting levels of glucose, insulin, leptin, and adiponectin in 392 patients enrolled in the Seattle Barrett's Esophagus Study. We calculated homeostatic model assessment scores (a measure of insulin sensitivity) and identified subjects with metabolic syndrome. We evaluated the association between these measures and the risk of EA using Cox regression models adjusted for known risk factors.

RESULTS

Increasing homeostatic model assessment scores were associated with an increasing risk for EA; the strongest association was observed within the first 3 years after participants entered the study (hazard ratio [HR], 2.45; 95% confidence interval [CI], 1.43-4.1; P trend = .001). Leptin level also was associated significantly with an increased risk of EA within 3 years (HR, 2.51; 95% CI, 1.09-5.81; P trend = .03) and 6 years (HR, 2.07; 95% CI, 1.01-4.26; P trend = .048) of baseline. The level of high-molecular-weight adiponectin had a nonlinear inverse association with risk of EA; the strongest associations were observed in the second tertile (HR, 0.34; 95% CI, 0.14-0.82). Metabolic syndrome was not associated with risk of EA.

CONCLUSIONS

Among patients with BE, increased levels of leptin and insulin resistance are associated with increased risk for EA, whereas increased levels of high-molecular-weight adiponectin is associated inversely with EA. These biomarkers might be used to determine cancer risk among patients with BE.

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.

Body mass index in relation to oesophageal and oesophagogastric junction adenocarcinomas: a pooled analysis from the International BEACON Consortium

BACKGROUND

Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms.

METHODS

Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender.

RESULTS

The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk.

CONCLUSIONS

These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

Alcohol consumption and digestive tract cancer

PURPOSE OF REVIEW

The data indicating that alcohol is an important factor increasing the risk to develop gastrointestinal cancer are consolidating. The purpose of this review is to summarize current evidence.

RECENT FINDINGS

Acetaldehyde is the first metabolite of ethanol metabolism and has direct carcinogenic and mutagenic effects by modifying DNA via generation of DNA adducts. Oxidative stress has a prominent role in triggering chronic inflammation and carcinogenesis through formation of reactive oxygen species. Recently published large prospective cohort studies with sufficient statistical power and meta-analyses could refine the knowledge regarding the impact of alcohol on gastrointestinal cancer. Functional genetic variants of alcohol-metabolizing enzymes proved to be associated with increased risk for esophageal and gastric cancer.The highest risk increase for malignancy was observed in the upper aerodigestive tract (oral cavity, pharynx, larynx) and esophagus (squamous cell carcinoma), weaker correlations were established regarding gastric, pancreatic, and colorectal neoplasias.

SUMMARY

Alcohol overconsumption is a serious avoidable risk factor for the development of gastrointestinal tract cancer, both alone but even more in combination with other risk factors such as tobacco and obesity.

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.

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.