A systematic review and meta-analysis of the risk of increasing adiposity on Barrett's esophagus

Gastroesophageal Reflux Disease in Obesity: Bariatric Surgery as Both the Cause and the Cure in the Morbidly Obese Population

Gastrointestinal reflux disease (GERD) is a chronic, highly prevalent condition in the United States. GERD can significantly impact quality of life and lead to complications including aspiration pneumonia, esophageal stricture, Barrett's esophagus (BE) and esophageal cancer. Obesity is a risk factor for GERD, which often improves with weight loss and bariatric surgery. Though the incidence of bariatric surgery, in particular, minimally invasive sleeve gastrectomy, has risen in recent years, emerging data has revealed that the severity or new onset of GERD may follow bariatric surgery. We performed a literature review to provide a detailed analysis of GERD with an emphasis on bariatric surgery as both the cure and the cause for GERD in the morbidly obese population. We also describe the pathophysiological mechanisms, management approach and treatment strategies of GERD following bariatric surgery.

Obesity, sleeve gastrectomy and gastro-esophageal reflux disease

Sleeve gastrectomy (SG) is the most frequently performed operation for morbid obesity in the world. In spite of its demonstrated efficacy, the Achilles' Heel of this procedure seems to be either pre-existing or de novo gastro-esophageal reflux disease (GERD) with its potential complications such as peptic esophagitis, Barrett's esophagus and, in the long-term, esophageal adenocarcinoma. According to factual literature, it appears clear that Roux-en-Y gastric bypass is the preferred choice in case of pre-existing GERD or hiatal hernia discovered during preoperative workup for bariatric surgery. Nonetheless, certain authors propose performance of SG with an associated antireflux procedure such as Nissen fundoplication. Strict endoscopic surveillance is recommended after bariatric surgery. Revisional surgery (conversion of SG into Roux-en-Y gastric bypass (RYGB)) is the treatment of choice for patients who develop GERD after SG when conservative treatment (modified lifestyle and proton pump inhibitors) has failed. Lastly, with regard to the risk of esophageal adenocarcinoma after SG, large scale studies with adequate follow-up are necessary to come to factual conclusions. In all cases, the management of this conundrum remains a major technical challenge that has to be taken in consideration in future years, especially because of the current expansion of bariatric surgery.

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.

Contribution of comorbidities to obesity-related asthma in children

Children with obesity are at increased risk for developing asthma that is difficult to control. A complicating factor to asthma management among these children is likely the commonplace co-morbidities that also result from obesity. We discuss three common obesity-related comorbidities which appear to complicate the effective management of asthma, including hypovitaminosis D, obstructive sleep apnea and gastro-esophageal reflux. Each conditions requires more research to understand their effects on asthma management.

Barrett's esophagus patients are becoming younger: analysis of a large United States dataset

BACKGROUND

Barrett's esophagus (BE), a complication of long-term gastroesophageal reflux disease (GERD), has been reported to affect 6-8% of those with heartburn. Most patients are males, Caucasians and middle aged. However, there are no recent demographic studies that evaluated the proportion trends of BE. We aimed to assess proportion trends of BE over an 11-year period, using a very large national dataset.

METHODS

This was a population-based analysis of the national Explorys dataset. Explorys is an aggregate of electronic medical record database representing over 54 million patients. Proportions of BE's variables such as age, gender, race, BMI, and treatment with PPI were recorded during an 11-year period. BE patients were classified into seven age groups (15-19, 20-29, 30-39, 40-49, 50-59, 60-69, ≥ 70 years old). Secular trends of the proportion of BE were assessed over time for each age group.

RESULTS

The majority of patients diagnosed with BE were ≥ 70 years old across all calendar years. However, the proportion of BE patients who were ≥ 70 years old has significantly decreased between 2006 and 2016 (- 19.9%, p < 0.001). The proportion of patients with BE increased in all age groups but most prominently in the age groups, 30-39: 2.07%, 40-49: 3.64%, 50-59: 6.89%, 60-69: 6.18%, p < 0.001. BE was significantly more common in those who were Caucasian and male. PPI usage fell significantly in those who were ≥ 70 years old (- 20.8%, p < 0.001), but increased in the other remaining age groups.

CONCLUSIONS

The proportion of BE patients who are 70 years and older has significantly dropped. Younger patients' groups have demonstrated the highest increase in the proportion of BE patients, especially those in the age group of 30-39 years old.

Epidemiologic Risk Factors in a Comparison of a Barrett Esophagus Registry (BarrettNET) and a Case-Control Population in Germany

Endoscopic screening for Barrett's esophagus as the major precursor lesion for esophageal adenocarcinoma is mostly offered to patients with symptoms of gastroesophageal reflux disease (GERD). However, other epidemiologic risk factors might affect the development of Barrett's esophagus and esophageal adenocarcinoma. Therefore, efforts to improve the efficiency of screening to find the Barrett's esophagus population "at risk" compared with the normal population are needed. In a cross-sectional analysis, we compared 587 patients with Barrett's esophagus from the multicenter German BarrettNET registry to 1976 healthy subjects from the population-based German KORA cohort, with and without GERD symptoms. Data on demographic and lifestyle factors, including age, gender, smoking, alcohol consumption, body mass index, physical activity, and symptoms were collected in a standardized epidemiologic survey. Increased age, male gender, smoking, heavy alcohol consumption, low physical activity, low health status, and GERD symptoms were significantly associated with Barrett's esophagus. Surprisingly, among patients stratified for GERD symptoms, these associations did not change. Demographic, lifestyle, and clinical factors as well as GERD symptoms were associated with Barrett's esophagus development in Germany, suggesting that a combination of risk factors could be useful in developing individualized screening efforts for patients with Barrett's esophagus and GERD in Germany.

Association between visceral abdominal obesity and long-segment Barrett's esophagus in a Japanese population

BACKGROUND

Visceral abdominal obesity is associated with Barrett's esophagus (BE), especially long-segment BE (≥ 3 cm) (LSBE), in white individuals. However, the association between central obesity and LSBE has not been well investigated in Asia. The aim of this study was to investigate the association between central obesity and LSBE in the Japanese population.

METHODS

A total of 38,298 healthy subjects who took medical surveys between April 2006 and November 2018 were enrolled. We investigated the association between LSBE and central obesity indices [visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and the VAT to SAT ratio (VAT/SAT)] using a multivariable logistic regression model.

RESULTS

A total of 37,686 subjects were eligible for the analysis. LSBE rates in the middle and high VAT/SAT groups were higher than those in the low VAT/SAT group [odds ratio (OR) 1.70, 95% confidence interval (CI) 1.07-2.69 for middle vs low; OR 2.02, 95% CI 1.17-3.49 for high vs low). These associational trends between VAT/SAT and LSBE remained in subgroups with and without reflux esophagitis. From subgroup analyses by SAT, we found that the OR between VAT and LSBE is higher in the low SAT subgroup (OR 2.43, 95% CI 1.34-4.40 for middle vs low; OR 2.55, 95% CI 1.01-6.40 for high vs low); but not large or imprecise due to limited event numbers in the middle and high SAT subgroups.

CONCLUSIONS

VAT was associated with LSBE, especially among subjects with low SAT accumulation, who are seemingly not obese. VAT/SAT was associated with LSBE regardless of the presence of reflux esophagitis in a Japanese population.

Prediagnostic circulating markers of inflammation and risk of oesophageal adenocarcinoma: a study within the National Cancer Institute Cohort Consortium

OBJECTIVE

Cross-sectional data indicate that systemic inflammation is important in oesophageal adenocarcinoma. We conducted a prospective study to assess whether prediagnostic circulating markers of inflammation were associated with oesophageal adenocarcinoma and to what extent they mediated associations of obesity and cigarette smoking with cancer risk.

DESIGN

This nested case-control study included 296 oesophageal adenocarcinoma cases and 296 incidence density matched controls from seven prospective cohort studies. We quantitated 69 circulating inflammation markers using Luminex-based multiplex assays. Conditional logistic regression models estimated associations between inflammation markers and oesophageal adenocarcinoma, as well as direct and indirect effects of obesity and smoking on risk of malignancy.

RESULTS

Soluble tumour necrosis factor receptor 2 (sTNFR2) (ORsquartile 4 vs 1=2.67, 95% CI 1.52 to 4.68) was significantly associated with oesophageal adenocarcinoma. Additional markers close to the adjusted significance threshold included C reactive protein, serum amyloid A, lipocalin-2, resistin, interleukin (IL) 3, IL17A, soluble IL-6 receptor and soluble vascular endothelial growth factor receptor 3. Adjustment for body mass index, waist circumference or smoking status slightly attenuated biomarker-cancer associations. Mediation analysis indicated that sTNFR2 may account for 33% (p=0.005) of the effect of waist circumference on oesophageal adenocarcinoma risk. Resistin, plasminogen activator inhibitor 1, C reactive protein and serum amyloid A were also identified as potential mediators of obesity-oesophageal adenocarcinoma associations. For smoking status, only plasminogen activator inhibitor 1 was a nominally statistically significant (p<0.05) mediator of cancer risk.

CONCLUSION

This prospective study provides evidence of a link between systemic inflammation and oesophageal adenocarcinoma risk. In addition, this study provides the first evidence that indirect effects of excess adiposity and cigarette smoking, via systemic inflammation, increase the risk of oesophageal adenocarcinoma.

Pathology, Chemoprevention, and Preclinical Models for Target Validation in Barrett Esophagus

Despite esophageal adenocarcinoma (EAC) being the most widespread among gastrointestinal cancers, with an 11-fold increase in the risk of cancer for patients with Barrett esophagus (BE), its prognosis is still poor. There is a critical need to better perceive the biology of cancer progression and identification of specific targets that are the hallmark of BE's progression. This review explores the established animal models of BE, including genetic, surgical and nonsurgical approaches, potential chemoprevention targets, and the reasoning behind their applications to prevent Barrett-related EAC. The key methodological features in the design feasibility of relevant studies are also discussed. Cancer Res; 78(14); 3747-54. ©2018 AACR.

Tissue protein biomarker candidates to predict progression of esophageal squamous cell carcinoma and precancerous lesions

Esophageal squamous cell carcinoma (ESCC) is one of the most predominant malignancies worldwide. The 5-year survival rate is still relatively low due to few symptoms presenting with the early disease, diagnosis at middle to late stage, and high risk of recurrence after therapy. Novel protein biomarkers for early detection and treatment of ESCC have the potential to reduce incidence and mortality rates, and significantly prolong the 5-year survival rate. To date, several ESCC biomarkers are being investigated for screening, diagnosis, and treatment to decrease the disease burden. This review summarizes recent developments in candidate protein biomarkers for early diagnosis, predictors for precancerous disease progression, and prognosis of ESCC. Protein biomarkers that enable identification of the different pathologic grades of ESCC will need to be identified. ESCC biomarkers have the potential to improve screening and treatment strategies; multicenter prospective studies with large sample sizes will be required to confirm the usefulness of these candidate biomarkers.

Gastrin stimulates a cholecystokinin-2-receptor-expressing cardia progenitor cell and promotes progression of Barrett's-like esophagus

Objective

The incidence of esophageal adenocarcinoma (EAC) is increasing, but factors contributing to malignant progression of its precursor lesion, Barrett's esophagus (BE), have not been defined. Hypergastrinemia caused by long-term use of proton pump inhibitors (PPIs), has been suggested as one possible risk factor. The gastrin receptor, CCK2R, is expressed in the cardia and upregulated in BE, suggesting the involvement of the gastrin-CCK2R pathway in progression. In the L2-IL-1β mouse model, Barrett's-like esophagus arises from the gastric cardia. Therefore, we aimed to analyze the effect of hypergastrinemia on CCK2R+ progenitor cells in L2-IL-1β mice.

Design

L2-IL-1β mice were mated with hypergastrinemic (INS-GAS) mice or treated with PPIs to examine the effect of hypergastrinemia in BE progression. CCK2R-CreERT crossed with L2-IL-1β mice were used to analyze the lineage progenitor potential of CCK2R+ cells. Cardia glands were cultured in vitro, and the effect of gastrin treatment analyzed. L2-IL-1β mice were treated with a CCK2R antagonist YF476 as a potential chemopreventive drug.

Results

Hypergastrinemia resulted in increased proliferation and expansion of Barrett's-like esophagus. Lineage tracing experiments revealed that CCK2R+ cells are long-lived progenitors that can give rise to such lesions under chronic inflammation. Gastrin stimulated organoid growth in cardia culture, while CCK2R inhibition prevented Barrett's-like esophagus and dysplasia.

Conclusions

Our data suggest a progression model for BE to EAC in which CCK2R+ progenitor cells, stimulated by hypergastrinemia, proliferate to give rise to metaplasia and dysplasia. Hypergastrinemia can result from PPI use, and the effects of hypergastrinemia in human BE should be studied further.

Validation study of a new semi-automated software program for CT body composition analysis

BACKGROUND

Computed tomography (CT) has been increasingly used to quantify abdominal muscle and fat in clinical research studies, and multiple studies have shown importance of body composition in predicting clinical outcome. The purpose of study is to compare newly developed semi-automated software (BodyCompSlicer) to commercially available validated software (Slice-O-Matic) for CT body composition analysis.

METHODS

CT scans of abdomen at L3 level in 30 patients were analyzed by two reviewers and using two softwares (BodyCompSlicer and Slice-O-Matic). Body composition analysis using BodyCompSlicer was semi-automated. The program automatically segmented subcutaneous fat (SF), skeletal muscle (SM), and visceral fat (VF) areas. Reviewers manually corrected the segmentation using computer-mouse interface as necessary. Body composition analysis using Slice-O-Matic was performed by manually segmenting each area using computer-mouse interface (brush tool). After segmentation, SM, SF, and VF areas were calculated using CT attenuation thresholds. Inter-observer and inter-software variability of measurements were analyzed using intraclass correlation coefficients (ICC) and coefficient of variation (COV).

RESULTS

Inter-observer ICC and COV using BodyCompSlicer were 0.997 and 1.5% for SM, 1.000 and 0.8% for SF, and 1.000 and 1.0% for VF, whereas those using Slice-O-Matic were 0.993 and 2.5% for SM, 0.995 and 3.1% for SF, and 0.999 and 2.3% for VF. Inter-software ICCs and COV were 0.995-0.995 and 2.0-2.1% for SM, 0.991-0.994 and 3.4-3.9% for SF, and 0.998-0.998 and 2.8-3.3% for VF. Time to analyze 30 cases was 70-100 min and 150-180 min using BodyCompSlicer and Slice-O-Matic, respectively.

CONCLUSION

BodyCompSlicer is comparable to Slice-O-Matic for CT body composition analysis.

The Troublesome Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus and esophageal adenocarcinoma diagnoses have increased markedly in recent decades. Recent research with patients diagnosed with Barrett's esophagus (the only known precursor for esophageal adenocarcinoma) and esophageal adenocarcinoma has identified several modifiable and nonmodifiable potential risk factors. Consistent risk factors for both disorders include increasing age, male sex, white non-Hispanic race/ethnicity, gastroesophageal reflux disease, lack of infection with Helicobacter pylori, smoking, abdominal obesity, and a Western diet. The authors present detailed discussions of these risk factors along with possible explanations for some apparent discrepancies and ideas for future study.

Gastrointestinal Complications of Obesity

Obesity usually is associated with morbidity related to diabetes mellitus and cardiovascular diseases. However, there are many gastrointestinal and hepatic diseases for which obesity is the direct cause (eg, nonalcoholic fatty liver disease) or is a significant risk factor, such as reflux esophagitis and gallstones. When obesity is a risk factor, it may interact with other mechanisms and result in earlier presentation or complicated diseases. There are increased odds ratios or relative risks of several gastrointestinal complications of obesity: gastroesophageal reflux disease, erosive esophagitis, Barrett's esophagus, esophageal adenocarcinoma, erosive gastritis, gastric cancer, diarrhea, colonic diverticular disease, polyps, cancer, liver disease including nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, gallstones, acute pancreatitis, and pancreatic cancer. Gastroenterologists are uniquely poised to participate in the multidisciplinary management of obesity as physicians caring for people with obesity-related diseases, in addition to their expertise in nutrition and endoscopic interventions.

Esophageal squamous papilloma lacks clear clinicopathological associations

AIM

To determine the prevalence of esophageal squamous papillomas (ESPs) in a tertiary teaching hospital and to assess for any clinical associations, including relations with esophageal squamous cell carcinomas (SCCs).

METHODS

Data from a total of 6962 upper gastrointestinal endoscopies over a five year period were retrospectively obtained and analysed.

RESULTS

ESP was found in sixteen patients (0.23%). Eight (50%) patients had a high body mass index, seven (44%) had history of cigarette smoking. Reflux esophagitis was found in four (25%) patients. All ESPs were solitary with a mean endoscopic size of 3.8 mm and located in the mid to lower esophagus. Human papilloma virus (HPV) was tested in three (19%) patients and was negative. Esophageal SCC was found in seven patients (0.10%) during the same period. None of the specimens were tested for HPV, and none had associated papillomatous changes.

CONCLUSION

ESP is an uncommon tumour with unclear clinical associations and malignant potential.

Central Obesity and H. pylori Infection Influence Risk of Barrett's Esophagus in an Asian Population

Background and Aim

The prevalence rates of Barrett’s esophagus (BE) in western countries are higher than Asian ones, but little is known about their difference among risk factors of BE. The aim of this study is to investigate the associations of various risk factors including central obesity, body mass index (BMI), metabolic syndrome and H. pylori infection, with BE.

Methods

A total of 161 subjects with BE were enrolled and compared to age- and gender-matched controls randomly sampled (1:4) from check-up center in same hospital. Central obesity was defined by waist circumference (female>80cm; male>90cm), metabolic syndrome by the modified National Cholesterol Education Program Adult Treatment Panel III criteria in Taiwan. Independent risk factors for BE were identified by multiple logistic regression analyses.

Results

The mean age for BE was 53.8±13.7 years and 75.8% was male. H. pylori infection status was detected by the rapid urease test with the prevalence of 28.4% and 44.4% in the BE patients and controls, respectively. The univariate logistic regression analyses showed the risk was associated with higher waist circumference (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.78–3.60), metabolic syndrome (OR, 2.02; 95% CI, 1.38–2.96) and negative H. pylori infection (OR, 0.50; 95% CI, 0.34–0.74). However, multivariate logistic regression analyses revealed that BE associated with higher waist circumference (adjusted OR, 2.79; 95% CI, 1.89–4.12) and negative H. pylori infection (adjusted OR, 0.46; 95% CI, 0.30–0.70).

Conclusions

Central obesity is associated with a higher risk of BE whereas H. pylori infection with a lower risk in an ethnic Chinese population.

Is Metabolic Syndrome Considered to Be a Risk Factor for Gastroesophageal Reflux Disease (Non-Erosive or Erosive Esophagitis)?: A Systematic Review of the Evidence

CONTEXT

The incidences of both gastroesophageal reflux disease (GERD) and metabolic syndrome (MetS) have increased in recent years, and it has been suggested that there is a probable association between the two. The aim of this review is to clarify whether or not MetS is a risk factor for the incidence of GERD.

EVIDENCE AQUISITION

We searched the PubMed, ProQuest, Ovid, Science Direct, and Google Scholar databases up to February 2015 regarding the relationship between GERD and MetS as found in observational studies. Any studies that evaluated the association between the components of MetS and GERD, as well as any studies examining the association of MetS with Barrett's esophagus or esophageal carcinoma, were excluded.

RESULTS

Thirteen studies met the eligibility criteria. The results of nine studies suggested that there was a higher prevalence of MetS among patients with GERD (P < 0.05) and, thus, it could be considered as an independent risk factor for the incidence of GERD. However, in the one study was not observed significant association between GERD and MetS (P = 0.71). Two studies in which the prevalence of GERD was compared between individuals with and without MetS showed a higher prevalence of GERD in patients with MetS (P < 0.05). However, this finding was not observed in a similar study conducted among female participants, which reported that the different types of MetS were not important factors with regard to the prevalence of erosive esophagitis (P = Not significant).

CONCLUSIONS

It can be concluded that MetS may increase the risk of GERD. Consequently, there might be potential benefits to treating the metabolic abnormalities in these patients.

Influence of body mass index on the prevalence and progression of dysplasia in Barrett's esophagus: a retrospective analysis (.)

OBJECTIVE

High body mass index (BMI) is a risk factor for Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Our aim was to determine if prevalence of dysplasia in BE varies by BMI and study the effect of BMI on progression to high-grade dysplasia (HGD) or EAC.

MATERIALS AND METHODS

This is a retrospective review of patients with endoscopic evidence of BE confirmed by presence of intestinal metaplasia on histology from January 2000 to December 2012 at Cleveland Clinic. Patient demographics, BMI and endoscopic findings such as length of BE, dysplasia in BE and size of hiatal hernia were reviewed. Dysplasia was classified as no dysplasia (NDBE), low-grade dysplasia (LGD), HGD and EAC.

RESULTS

In this cohort of 1239 patients, average BMI was 29.8 ± 6 kg/m(2). There were 228 (18.4%) in group with BMI <25, 236 (19%) in BMI group 25-27.4, 262 (21.1%) in BMI 27.5-29.9, 303 (24.5%) in BMI 30-34.9, 126 (10.2%) in BMI 35-39.9 and 86 (6.8%) in BMI ≥40. Lower BMI groups had lower prevalence of dysplasia while higher BMI groups had higher prevalence of dysplasia (p = 0.002). During mean follow up of 31.6 ± 26 months, there were 14 cases of HGD/EAC in NDBE group and 29 cases of HGD/EAC in LGD group. BMI or BMI change was not associated with progression to HGD/EAC in NDBE.

CONCLUSIONS

High BMI was associated with higher prevalence of dysplasia in BE. But once in a surveillance program, higher BMI is not associated with progression of dysplasia in NDBE.

Epidemiology of Barrett's esophagus and esophageal adenocarcinoma in Spain. A unicentric study

INTRODUCTION

Barrett's esophagus (BE) is an acquired disease defined by the presence of intestinal metaplasia with goblet cells in the distal esophagus. The prevalence of BE has increased dramatically over the last years.

AIMS

The primary aims of the study were to analyze the characteristics of BE and esophageal adenocarcinoma (EAC) in a Spanish health district during a follow-up period.

METHODOLOGY

Sociodemographic factors, alcohol consumption and cigarette smoking were analyzed. We also studied the histological behavior and cause of death in each group.

RESULTS

In the present study 430 patients were included, 338 with BE and 92 with EAC. Incidence rates have risen from 2.25 and 1.25 per 100,000 inhabitants in 1996 to 6.5 and 4.75 per 100,000 in 2011, respectively. In the EAC group, male gender, age and alcohol consumption were higher in comparison to the BE group, and the overall survival was 23 months. In the BE group, the main causes of death were non-esophageal cancer and cardiovascular disease.

CONCLUSIONS

The incidence and prevalence rates of AEC and BE have risen over the past years. Risk factors for these conditions were male gender, age and alcohol consumption. Long BE (> 3 cm) is involved in dysplasia progression. AEC diagnosis mainly occurs after neoplasia is detected and, in a few cases, due to a previous BE. Cardiovascular diseases and non-esophageal cancers have been found to be the main cause of death in BE patients.

Metabolic syndrome is associated with increased risk of Barrett esophagus: A meta-analysis

BACKGROUND

Barrett esophagus (BE) is considered precursor condition of esophageal adenocarcinoma. Its incidence and prevalence are increasing in general population. Studies reported that metabolic syndrome (MS) or diabetes mellitus (DM) is related to increased risk of BE. Current study was to assess and better understand the relationship between MS /DM and BE.

METHODS

Electronic search was conducted in the database Pubmed/Medline (-December, 2015), Embase (-December, 2015), Cochrane Library (-December, 2015), and Web of Knowledge (-December, 2015). Studies included were assessed with summary odds ratios (ORs) with 95% confidence intervals (CIs) and compared exposure group with control group. The heterogeneity was examined by the funnel plot and the Egger's test. Subgroup analyses and sensitive analyses were performed for the detection of possible heterogeneity and impact on stability of analysis results.

RESULTS

Twelve publications met the criteria and included 355,311 subjects were analyzed. The pooled results showed MS was closely associated with increased risk of BE (OR = 1.23; 95%CI 1.03-1.47; P = 0.024), and yet DM did not significantly increase the risk of BE (OR = 1.07; 95%CI 0.82-1.38; P = 0.627). Substantial heterogeneities were detected. No significant publication bias was detected by Egger's test (P = 0.23).

CONCLUSIONS

Based on the results of current meta-analysis, MS is associated with increased risk of BE. Further long-term follow-up prospective study needs to verify the current results, and definite pathophysiological mechanism needs to be further investigated and clearly elucidated.

An Analysis of Weight Gains and Body Mass Index in Patients with Barrett's Esophagus

BACKGROUND

Obesity is a risk factor for developing Barrett's esophagus (BE), a precursor to esophageal cancer. Long BE lengths are associated with greater risk for malignancy. How weight gains from young adulthood (defined as ages 19 to 29 years) affect BE length is unknown.

OBJECTIVE

To examine current body mass index (BMI), weight gains from young adulthood, and evening snacking near bedtime during young adulthood in BE patients.

DESIGN

Cross-sectional analysis of 71 patients from 2001 to 2008 from a 600-bed tertiary care center in the United States who were newly diagnosed with BE by endoscopy and mucosal biopsies.

MAIN OUTCOME MEASURES

Barrett's esophagus length and age at presentation.

STATISTICAL ANALYSES PERFORMED

Pearson's correlation coefficient (r) measured the linear association between continuous variables. The Kruskal-Wallis test was used to compare medians by segment length and the chi-squared test or Fisher's exact test for categorical data. Quantile regression was used for multivariable adjustment.

RESULTS

Younger patients had higher BMIs at diagnosis (r=-0.32, P=0.007). Patients who gained more than 23 kg from young adulthood were diagnosed at an adjusted median age of 18.0 years younger 95% CI (6.1-29.9, P=0.004) than patients with no weight gains. BMI was not correlated with BE length (r=-0.12, P=0.33). Weight gains from young adulthood were not associated with BE length after multivariable adjustment (P=0.19). Patients whose late evening snack or bedtime was less than 4 hours from dinner had longer median BE lengths than those who went to bed later (5 vs 2 cm, P=0.02).

CONCLUSIONS

Longer BE lengths were associated with shorter dinner-bedtime intervals during young adulthood but not with current BMI or weight gains from young adulthood.

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.

Role of body composition and metabolic profile in Barrett's oesophagus and progression to cancer

BACKGROUND AND AIMS

The aim of this study was to evaluate the risk for Barrett's oesophagus (BE) on the basis of body composition, metabolic pathways, adipokines and metabolic syndrome (MS), as well as their role in cancer progression.

METHODS

In patients with and without BE at gastroscopy, data on MS, BMI, waist/hip ratio for abdominal obesity (AO) and body fat percentage by bioimpedance were obtained. Fasting plasma glucose, insulin, HbA1c, lipid, serum adiponectin and leptin levels were measured. The homoeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. Histological findings for BE were correlated with the above parameters. Risk factors for BE identified using univariate analysis were entered into a multivariate logistic regression analysis.

RESULTS

A total of 250 patients and 224 controls (F/M: 189/285, mean age 58.08±15.51 years) were enroled. In the BE and control groups, 39.6 versus 31.3% were overweight, 32 versus 22.8% were obese, 75.6 versus 51.3% had AO, and 28.1 versus 18.9% were metabolically obese, respectively. AO [odds ratio (OR) 3.08], increased body fat percentage (OR 2.29), and higher BMI (overweight: OR 2.04; obese: OR 2.26) were significantly associated with BE. A positive trend was found in Normal Weight Obese Syndrome (OR 1.69). MS was associated with BE (overweight: OR 3.05; obese: OR 5.2; AO: OR 8.08). Insulin levels (P=0.05) and HOMA-IR (P<0.001) were higher in BE. AO was the only independent risk factor associated with BE (OR 1.65; P=0.02) and high-grade dysplasia (OR 2.44) on multivariate analysis.

CONCLUSION

AO was strongly associated with BE and dysplasia. BE was associated with MS and higher insulin/HOMA-IR, suggesting the activation of specific metabolic pathways in patients with altered body composition.

Associations of Serum Adiponectin and Leptin With Barrett's Esophagus

BACKGROUND & AIMS

Central adiposity is a risk factor for Barrett's esophagus (BE). Serum levels of adiponectin and leptin are deregulated in obese states and are implicated as putative mediators in the pathophysiology of esophageal columnar metaplasia. We describe associations between serum adiponectin and leptin levels with BE.

METHODS

Patients were recruited prospectively for a case-control study. Fasting serum levels of adiponectin and leptin were measured in 135 patients with BE and compared with 2 separate control groups: 133 subjects with gastroesophageal reflux disease (GERD) and 1157 colon screening controls.

RESULTS

Multivariate analyses adjusted for age, race, and waist-to-hip ratio showed that patients within the highest tertile of serum adiponectin level had decreased odds of BE compared with screening colonoscopy controls (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.22-0.80). This effect was more pronounced in men (OR, 0.35; 95% CI, 0.17-0.74) compared with women (OR, 0.71; 95% CI, 0.17-3.03). In comparisons of BE cases with GERD controls, subjects within the highest tertile of serum adiponectin level showed decreased odds of BE (OR, 0.65; 95% CI, 0.31-1.36), however, this was not statistically significant. Patients in the highest tertile of serum leptin level did not have a significantly increased risk of BE in comparison with GERD (OR, 1.32; 95% CI, 0.61-2.88) or screening colonoscopy controls (OR, 1.57; 95% CI, 0.82-3.04) in analyses including both sexes. Based on sex-specific analyses, sex did not significantly alter the association of leptin with odds of BE.

CONCLUSIONS

Serum adiponectin was associated inversely with BE and this effect was more pronounced in men, whereas serum leptin showed no evidence of association with BE in comparisons with multiple control groups. The exact mechanism, if any, by which these adipokines promote metaplasia in the esophagus needs to be explored further.

Prevalence of Barrett's Esophagus in Asian Countries: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The prevalence and risk factors of Barrett's esophagus (BE) in Asian countries are unclear. Studies report a wide range of BE prevalence in Asian countries. We conducted a systematic review and meta-analysis to examine the prevalence of BE and its temporal changes and risk factors in Asian countries.

METHODS

Two investigators performed independent literature searches by using PubMed and EMBASE databases, and subsequent data abstraction for studies had to meet several set inclusion and exclusion criteria. Pooled BE prevalence was calculated by using a random-effect model. Estimates of relative risk for possible risk or protective factors were also calculated.

RESULTS

A total of 51 studies (N = 453,147), mainly from Eastern Asia, were included. The pooled prevalence of endoscopic BE was 7.8% (95% confidence interval, 5.0-12.1; 23 studies) and of histologically confirmed BE was 1.3% (95% confidence interval, 0.7-2.2; 28 studies). Most of histologic BE (82.1%) was short-segment BE (<3 cm). There was a trend toward an increase in prevalence of BE over time from 1991 to 2014, especially in Eastern Asian countries. Within BE cohorts, pooled prevalence of low-grade dysplasia, high-grade dysplasia, and esophageal adenocarcinoma was 6.9%, 3.0%, and 2.0%, respectively. Reflux symptoms, male sex, hiatus hernia, and smoking were associated with a significantly increased risk of histologic BE in patients with BE compared with patients without BE. However, half of the patients with histologic BE did not have reflux symptoms.

CONCLUSIONS

BE is not uncommon in Asian countries and seems to share similar risk factors and potential for neoplastic progression to those seen in Western countries.

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.

Role of Obesity in the Pathogenesis and Progression of Barrett's Esophagus

Central obesity is involved in the pathogenesis and progression of Barrett's esophagus to esophageal adenocarcinoma. Involved are likely both mechanical and nonmechanical effects. Mechanical effects of increased abdominal fat cause disruption of the gastroesophageal reflux barrier leading to increased reflux events. Nonmechanical effects may be mediated by inflammation, via classically activated macrophages, pro-inflammatory cytokines, and adipokines such as Leptin, all of which likely potentiate reflux-mediated inflammation. Insulin resistance, associated with central obesity, is also associated with both Barrett's pathogenesis and progression to adenocarcinoma. Molecular pathways activated in obesity, inflammation and insulin resistance overlap with those involved in Barrett's pathogenesis and progression.

Risk factors affecting the Barrett's metaplasia-dysplasia-neoplasia sequence

Esophageal adenocarcinoma has the fastest growing incidence rate of any cancer in the United States, and currently carries a very poor prognosis with 5 years relative survival rates of less than 15%. Current curative treatment options are limited to esophagectomy, a procedure that suffers from high complication rates and high mortality rates. Metaplasia of the esophageal epithelium, a condition known as Barrett’s esophagus (BE), is widely accepted as the precursor lesion for adenocarcinoma of the esophagus. Recently, radio-frequency ablation has been shown to be an effective method to treat BE, although there is disagreement as to whether radio-frequency ablation should be used to treat all patients with BE or whether treatment should be reserved for those at high risk for progressing to esophageal adenocarcinoma while continuing to endoscopically survey those with low risk. Recent research has been targeted towards identifying those at greater risk for progression to esophageal adenocarcinoma so that radio-frequency ablation therapy can be used in a more targeted manner, decreasing the total health care cost as well as improving patient outcomes. This review discusses the current state of the literature regarding risk factors for progression from BE through dysplasia to esophageal adenocarcinoma, as well as the current need for an integrated scoring tool or risk stratification system capable of differentiating those patients at highest risk of progression in order to target these endoluminal therapies.

Metabolic syndrome increases risk of Barrett esophagus in the absence of gastroesophageal reflux: an analysis of SEER-Medicare Data

GOALS

To evaluate the association between metabolic syndrome (MetS) and risk of Barrett esophagus (BE) using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database compared with 2 control groups--Medicare population controls and endoscopy controls.

BACKGROUND

BE principally arises as an adaptation to the proinflammatory state induced by gastroesophageal reflux disease (GERD). The relationship between obesity and BE is presumed to be mediated by GERD. However, evidence suggests central adiposity also increases risk of BE independent of GERD. Central adiposity is one risk factor defining MetS, which confers a systemic proinflammatory state--a potential GERD-independent mechanism by which obesity could increase the risk of BE.

STUDY

MetS was defined as diagnosis of at least 3 of the following conditions: obesity, elevated triglycerides, high blood pressure, and elevated fasting glucose. Multivariable logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals.

RESULTS

In 2198 incident BE cases, prior MetS was significantly associated with BE (odds ratio, 1.20; 95% confidence interval: 1.07, 1.36) compared with population controls. However, GERD status modified the association; among those without prior GERD, MetS increased risk of BE by 34%; however, no association was observed among those with a prior GERD diagnosis (P-value for effect modification <0.001). MetS was not associated with risk of BE compared with endoscopy controls.

CONCLUSIONS

MetS increased the risk of BE compared with population controls, an association driven by and confined to the non-GERD stratum. MetS may mediate an association between central adiposity and BE for those without GERD.

Screening for Barrett's esophagus and esophageal adenocarcinoma: rationale, recent progress, challenges, and future directions

As the incidence and mortality of esophageal adenocarcinoma continue to increase, strategies to counter this need to be explored. Screening for Barrett's esophagus, which is the known precursor of a large majority of adenocarcinomas, has been debated without a firm consensus. Given evidence for and against perceived benefits of screening, the multitude of challenges in the implementation of such a strategy and in the downstream management of subjects with Barrett's esophagus who could be diagnosed by screening, support for screening has been modest. Recent advances in the form of development and initial accuracy of noninvasive tools for screening, risk assessment tools, and biomarker panels to risk stratify subjects with BE, have spurred renewed interest in the early detection of Barrett's esophagus and related neoplasia, particularly with the advent of effective endoscopic therapy. In this review, we explore in depth the potential rationale for screening for Barrett's esophagus, recent advances that have the potential of making screening feasible, and also highlight some of the challenges that will have to be overcome to develop an effective approach to improve the outcomes of subjects with esophageal adenocarcinoma.

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

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

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.

Obesity and risk of esophageal adenocarcinoma and Barrett's esophagus: a Mendelian randomization study

BACKGROUND

Data from observational studies suggest that body mass index (BMI) is causally related to esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE). However, the relationships may be affected by bias and confounding.

METHODS

We used data from the Barrett's and Esophageal Adenocarcinoma Genetic Susceptibility Study: 999 patients with EAC, 2061 patients with BE, and 2169 population controls. We applied the two-stage control function instrumental variable method of the Mendelian randomization approach to estimate the unbiased, unconfounded effect of BMI on risk of EAC and BE. This was performed using a genetic risk score, derived from 29 genetic variants shown to be associated with BMI, as an instrument for lifetime BMI. A higher score indicates propensity to obesity. All tests were two-sided.

RESULTS

The genetic risk score was not associated with potential confounders, including gastroesophageal reflux symptoms and smoking. In the instrumental variable analyses (IV), EAC risk increased by 16% (IV-odds ratio [OR] = 1.16, 95% confidence interval [CI] = 1.01 to 1.33) and BE risk increased by 12% (IV-OR = 1.12, 95% CI = 1.00 to 1.25) per 1kg/m(2) increase in BMI. BMI was statistically significantly associated with EAC and BE in conventional epidemiologic analyses.

CONCLUSIONS

People with a high genetic propensity to obesity have higher risks of esophageal metaplasia and neoplasia than people with low genetic propensity. These analyses provide the strongest evidence to date that obesity is independently associated with BE and EAC, and is not due to confounding or bias inherent in conventional epidemiologic analyses.

Barrett’s oesophagus: Evidence from the current meta-analyses

Guidelines have been published regarding the management of Barrett’s oesophagus (columnar-lined oesophagus). These have examined the role of surveillance in an effort to detect dysplasia and early cancer. The guidelines have provided criteria for enrolment into surveillance and some risk stratification with regard to surveillance interval. The research basis for the decisions reached with regard to cancer risk is weak and this manuscript has examined the available data published from meta-analyses up to 25^th April 2013 (much of which has been published since the guidelines and their most recent updates have been written). There were 9 meta-analyses comparing patients with Barrett’s oesophagus to control populations. These have demonstrated that Barrett’s oesophagus is more common in males than females, in subjects who have ever smoked, in subjects with obesity, in subjects with prolonged symptoms of gastro-oesophageal reflux disease, in subjects who do not have infection with Helicobacter pylori and in subjects with hiatus hernia. These findings should inform public health measures in reducing the risk of Barrett’s oesophagus and subsequent surveillance burden and cancer risk. There were 8 meta-analyses comparing different groups of patients with Barrett’s oesophagus with regard to cancer risk. These have demonstrated that there was no statistically significant benefit of antireflux surgery over medical therapy, that endoscopic ablative therapy was effective in reducing cancer risk that there was similar cancer risk in patients with Barrett’s oesophagus independent of geographic origin, that the adenocarcinoma incidence in males is twice the rate in females, that the cancer risk in long segment disease showed a trend to be higher than in short segment disease, that there was a trend for higher cancer risk in low-grade dysplasia over non-dysplastic Barrett’s oesophagus, that there is a lower risk in patients with Helicobacter pylori infection and that there is a significant protective effect of aspirin and statins. There were no meta-analyses examining the role of intestinal metaplasia. These results demonstrate that guidance regarding surveillance based on the presence of intestinal metaplasia, segment length and the presence of low-grade dysplasia has a weak basis, and further consideration should be given to gender and helicobacter status, ablation of the metaplastic segment as well as the chemoprotective role of aspirin and statins.

Esophagus adenocarcinoma in a young patient with celiac disease; Is celiac disease a predisposing factor for esophagus adenocarcinoma as well as squamous cell carcinoma?

We report a 36-year-old female with longstanding oily diarrhea and new-onset dysphagia that was diagnosed as celiac disease and esophagus adenocarcinoma. Celiac is a multisystemic autoimmune disease associated with a longstanding inflammatory process, especially in the gastrointestinal tract. This chronic inflammation may lead to a modest increase in neoplasia risk. There is a modest increased risk of malignancy in celiac disease, particularly adenocarcinoma and T-cell lymphoma of the small intestine and squamous cell carcinoma (SCC) of the esophagus, mouth, and pharynx. Although there is an association between SCC of the esophagus and celiac disease, there are no reports in the English literature about a relationship between celiac disease and esophageal adenocarcinoma. This case shows that as well as SCC, adenocarcinoma of the esophagus may also occur in patients with longstanding celiac disease.

Total body fat and the risk of Barrett's oesophagus - a bioelectrical impedance study

BACKGROUND

Body mass index is associated with the risk of Barrett's oesophagus (BO). It is uncertain whether this is related to total body fat or other factors that correlate with body mass index. We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity.

METHODS

In 2007-2009, we surveyed 235 cases (69% Males, Mean age 62.1 years) and 244 age and sex matched population controls from a population based case-control study of BO. We conducted structured interviews, standard anthropometry and bioimpedance analysis of total body fat. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression analysis.

RESULTS

There was a significantly increased risk of BO among those in the highest tertile of total body fat weight (OR 2.01; 95%CI 1.26-3.21) and total body fat percentage (OR 1.86; 95%CI 1.10-3.15). These risks were largely attenuated after adjustment for GOR and waist circumference. There was a significantly increased risk of BO among those in the highest tertile of waist circumference (OR 2.21; 95%CI 1.39-3.51) and this was minimally attenuated after adjustment for total body fat and moderately attenuated after adjustment for GOR.

CONCLUSIONS

Total body fat is associated with an increased risk of BO but this appears to be mediated via both abdominal obesity and GOR. These findings provide evidence that abdominal obesity is more important than total body fat in the development of BO.

Leptin and adiponectin receptor expression in oesophageal cancer

BACKGROUND

Oesophageal adenocarcinoma is an exemplar model of an obesity-associated adenocarcinoma. Altered secretion of adipokines by visceral fat is believed to play a key role in tumorigenesis. This study examined leptin receptor (ObR) and adiponectin receptor (AdipoR1 and AdipoR2) expression in oesophageal cancer, and its relationship with patient obesity status, clinicopathological data and patient survival.

METHODS

Tissue microarrays were constructed from paraffin-embedded oesophagectomy specimens. ObR, AdipoR1 and AdipoR2 expression was quantified by immunohistochemistry. Anthropometric data were measured at the time of diagnosis, and obesity status was assessed using visceral fat area determined by computed tomography and body mass index. Receptor expression was correlated with various clinicopathological and anthropometric variables. Patient survival was estimated using the Kaplan-Meier method, and results compared between those with low versus high receptor expression. A Cox multivariable regression model was used to assess the relationship between survival and a number of co-variables.

RESULTS

All 125 tumours analysed expressed AdipoR1 and AdipoR2, whereas 96·8 per cent expressed ObR. There was no significant difference in tumour pathological features or patient obesity status between tumours with low versus high ObR expression. A high level of AdipoR1 expression was significantly associated with increased patient age, obesity and less advanced tumour (T) category. Expression of AdipoR2 was inversely associated with T category (P = 0.043). Low AdipoR1 expression was an independent predictor of improved overall survival (hazard ratio 0.56, 95 per cent confidence interval 0.35 to 0.90; P = 0.017).

CONCLUSION

The association between adiponectin receptor expression, obesity status and tumour category and survival suggests a potential mechanism linking obesity and oesophageal cancer.

Gastrointestinal morbidity in obesity

Obesity is a complex disease that results from increased energy intake and decreased energy expenditure. The gastrointestinal system plays a key role in the pathogenesis of obesity and facilitates caloric imbalance. Changes in gastrointestinal hormones and the inhibition of mechanisms that curtail caloric intake result in weight gain. It is not clear if the gastrointestinal role in obesity is a cause or an effect of this disease. Obesity is often associated with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Obesity is also associated with gastrointestinal disorders, which are more frequent and present earlier than T2DM and CVD. Diseases such as gastroesophageal reflux disease (GERD), cholelithiasis, or nonalcoholic steatohepatitis are directly related to body weight and abdominal adiposity. Our objective is to assess the role of each gastrointestinal organ in obesity and the gastrointestinal morbidity resulting in those organs from the effects of obesity.

Visceral abdominal obesity measured by CT scan is associated with an increased risk of Barrett's oesophagus: a case-control study

OBJECTIVE

Abdominal obesity has been associated with increased risk of Barrett's oesophagus (BE) but the underlying mechanism is unclear. We examined the association between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) and the risk of BE.

DESIGN

A case-control study among eligible patients scheduled for elective oesophagastroduodenoscopy (EGD) and in a sample of patients eligible for screening colonoscopy recruited at the primary care clinic. All cases with definitive BE and a random sample of controls without BE were invited to undergo standardised mid-abdomen non-contrast computerised axial tomography images, which were analysed by semiautomated image segmentation software. The effect of VAT and SAT surface areas and their ratio (VAT to SAT) on BE were analysed in logistic regression models.

RESULTS

A total of 173 BE cases, 343 colonoscopy controls and 172 endoscopy controls underwent study EGD and CT scan. Participants with BE were more than twice as likely to be in the highest tertile of VAT to SAT ratio (OR: 2.42 (1.51 to 3.88) and adjusted OR 1.47 (0.88 to 2.45)) than colonoscopy controls, especially for those long (≥3 cm) segment BE (3.42 (1.67 to 7.01) and adjusted OR 1.93 (0.92 to 4.09)) and for white men (adjusted OR 2.12 (1.15 to 3.90)). Adjustment for gastroesophageal reflux disease (GERD) symptoms and proton pump inhibitors (PPI) use attenuated this association, but there was a significant increase in BE risk even in the absence of GERD or PPI use.

CONCLUSIONS

Large amount of visceral abdominal fat relative to subcutaneous fat is associated with a significant increase in the risk of BE. GERD may mediate some but not all of this association.

Circulating inflammatory cytokines and adipokines are associated with increased risk of Barrett's esophagus: a case-control study

BACKGROUND & AIMS

Obesity is associated with Barrett's esophagus (BE) and with changes in circulating levels of adipokines (leptin and adiponectin) and cytokines. Although studies have reported that adipokines and inflammatory cytokines are necessary for the development of BE, their role is controversial.

METHODS

We performed a case-control study; cases (n = 141) were patients who underwent esophagogastroduodenoscopy and were found to have BE, which was based on endoscopy and histology, and controls (n = 139) were primary care patients eligible for screening colonoscopies who agreed to undergo esophagogastroduodenoscopy. We examined the association between BE and circulating levels of adipokines and cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, and IL-12p70; tumor necrosis factor-α; and interferon-γ). Cases and controls were compared by calculating odds ratios (ORs) and 95% confidence intervals (CIs) and using unadjusted and multiple logistic regression, adjusting for age, sex, race, waist-hip ratio, use of proton pump inhibitors and nonsteroidal anti-inflammatory drugs, and Helicobacter pylori infection.

RESULTS

The adjusted ORs for BE were 2.62 (95% CI, 1.0-6.8), 5.18 (95% CI, 1.7-15.7), and 8.02 (95% CI, 2.79-23.07) for the highest quintile vs the lowest quintile of levels of IL-12p70, IL-8, and leptin, respectively, but the OR was not significant for IL-6 (2.39; 95% CI, 0.84-6.79). The adjusted OR for BE was 0.14 for highest quintile of IL-10 compared with lowest quintile (95% CI, 0.05-0.35) and 0.03 for IL-1β ≥ median vs none detected (95% CI, 0.006-0.13). Higher levels of IL-8 and leptin and lower levels of IL-10 and IL-1β were associated with the presence of long-segment (≥3 cm) and short-segment BE. There were no differences between cases and controls in levels of interferon-γ, tumor necrosis factor-α, adiponectin, or insulin.

CONCLUSIONS

BE is associated with circulating inflammatory cytokines and leptin and low levels of anti-inflammatory cytokines. These findings could partly explain the effect of obesity on BE.

Adiponectin inhibits leptin-induced oncogenic signalling in oesophageal cancer cells by activation of PTP1B

Obesity is characterised by hyperleptinaemia and hypoadiponectinaemia and these metabolic abnormalities may contribute to the progression of several obesity-associated cancers including oesophageal adenocarcinoma (OAC). We have examined the effects of leptin and adiponectin on OE33 OAC cells. Leptin stimulated proliferation, invasion and migration and inhibited apoptosis in a STAT3-dependant manner. Leptin-stimulated MMP-2 secretion in a partly STAT3-dependent manner and MMP-9 secretion via a STAT3-independent pathway. Adiponectin inhibited leptin-induced proliferation, migration, invasion, MMP secretion and reduced the anti-apoptotic effects: these effects of adiponectin were ameliorated by both a non-specific tyrosine phosphatase inhibitor and a specific PTP1B inhibitor. Adiponectin reduced leptin-stimulated JAK2 activation and STAT3 transcriptional activity in a PTP1B-sensitive manner and adiponectin increased both PTP1B protein and activity. We conclude that adiponectin restrains leptin-induced signalling and pro-carcinogenic behaviour by inhibiting the early events in leptin-induced signal transduction by activating PTP1B. Relative adiponectin deficiency in obesity may contribute to the promotion of OAC.

Chemotherapeutic and targeted strategies for locally advanced and metastatic esophageal cancer

INTRODUCTION

: Esophageal cancer represents a major health care problem worldwide and its prevalence is rapidly increasing. A key challenge in the treatment of both locally advanced and metastatic disease is to improve our understanding of the underlying molecular biology. Herein we discuss the most active chemotherapies and targeted agents for esophageal cancer, and explore potential differences in the disease between Eastern and Western countries.

METHODS

: We reviewed the literature for trials involving chemotherapy and targeted agents in locally advanced and metastatic disease in the last 20 years. The search was supplemented by a review of the abstracts presented at the annual American Society of Clinical Oncology meetings from 1992 to 2012.

RESULTS

: Neoadjuvant chemo-radiation followed by surgery remains standard of care for operable disease. Definitive chemo-radiation can be considered for locally advanced squamous cell tumors. Platinum-based combination chemotherapy is preferable in the first-line metastatic setting. Recently, HER2, EGFR, and VEGF-targeted agents have been extensively investigated as single agents or in combination with chemotherapy. Several new targets are being explored.

CONCLUSIONS

: There have been incremental improvements in our understanding of the molecular biology of esophageal cancer, and ethnic differences between Asian and Western populations are becoming apparent. Next-generation sequencing has failed to demonstrate significant oncogenic drivers; however, the addition of trastuzumab to chemotherapy for HER2-amplified tumors has been validated in the metastatic setting and is undergoing investigation in operable disease. Epigenetic therapeutics may provide additional benefit in future years for this difficult-to-treat disease.

The role of obesity in gastrointestinal cancer: evidence and opinion

There is increasing recognition of the impact of being overweight and obese on the development of cancers at diverse sites including the gastrointestinal tract. Large epidemiological studies indicate that up to 14% of tumours may be related to obesity. Pathophysiological mechanisms underpinning this association are not well understood and so are discussed in this review.

Defining esophageal landmarks, gastroesophageal reflux disease, and Barrett's esophagus

The following paper on gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE) includes commentaries on defining esophageal landmarks; new techniques for evaluating upper esophageal sphincter (UES) tone; differential diagnosis of GERD, BE, and hiatal hernia (HH); the use of high-resolution manometry for evaluation of reflux; the role of fundic relaxation in reflux; the use of 24-h esophageal pH-impedance testing in differentiating acid from nonacid reflux and its potential inclusion in future Rome criteria; classification of endoscopic findings in GERD; the search for the cell origin that generates BE; and the relationship between BE, Barrett's carcinoma, and obesity.

Meta-analysis of Barrett’s esophagus in China

AIM: To investigate the epidemiology and characteristics of Barrett’s esophagus (BE) in China and compare with cases in the west.

METHODS: Studies were retrieved from the China National Knowledge Infrastructure and PubMed databases using the terms “Barrett” and “Barrett AND China”, respectively, as well as published studies about BE in China from 2000 to 2011. The researchers reviewed the titles and abstracts of all search results to determine whether or not the literature was relevant to the current topic of this research. The references listed in the studies were also searched. Inclusion and exclusion criteria for the literature were appropriately established, and the data reported in the selected studies were analyzed. Finally, a meta-analysis was performed.

RESULTS: The current research included 3873 cases of BE from 69 studies. The endoscopic detection rate of BE in China was 1%. The ratio of male to female cases was 1.781 to 1, and the average age of BE patients was 49.07 ± 5.09 years. Island-type and short-segment BE were the most common endoscopic manifestations, accounting for 4.48% and 80.3%, respectively, of all cases studied. Cardiac-type BE was observed in 40.0% of the cases, representing the most common histological characteristic of the condition. Cancer incidence was 1.418 per 1000 person-years.

CONCLUSION: Average age of BE patients in China is lower than in Western countries. Endoscopic detection and cancer incidence were also lower in China.

Liver stiffness is associated with risk of decompensation, liver cancer, and death in patients with chronic liver diseases: a systematic review and meta-analysis

BACKGROUND & AIMS

Liver stiffness measurement (LSM), using elastography, can independently predict outcomes of patients with chronic liver diseases (CLDs). However, there is much variation in reporting and consistency of findings. We performed a systematic review and meta-analysis to evaluate the association between LSM and outcomes of patients with CLDs.

METHODS

We performed a systematic review of the literature, through February 2013, for studies that followed up patients with CLDs prospectively for at least 6 months and reported the association between baseline LSM and subsequent development of decompensated cirrhosis or hepatocellular carcinoma (HCC), as well as mortality. Summary relative risk (RR) estimates per unit of LSM and 95% confidence intervals (CIs) were estimated using the random effects model.

RESULTS

Our final analysis included 17 studies, reporting on 7058 patients with CLDs. Baseline LSM was associated significantly with risk of hepatic decompensation (6 studies; RR, 1.07; 95% CI, 1.03-1.11), HCC (9 studies; RR, 1.11; 95% CI, 1.05-1.18), death (5 studies; RR, 1.22; 95% CI, 1.05-1.43), or a composite of these outcomes (7 studies; RR, 1.32; 95% CI, 1.16-1.51). We observed considerable heterogeneity among studies-primarily in the magnitude of effect, rather than the direction of effect. This heterogeneity could not be explained by variations in study locations, etiologies and stages of CLD, techniques to measure liver stiffness, adjustment for covariates, or method of imputing relationship in the meta-analysis.

CONCLUSIONS

Based on a meta-analysis of cohort studies, the degree of liver stiffness is associated with risk of decompensated cirrhosis, HCC, and death in patients with CLDs. LSM therefore might be used in risk stratification.

Central adiposity is associated with increased risk of esophageal inflammation, metaplasia, and adenocarcinoma: a systematic review and meta-analysis

BACKGROUND & AIMS

Central adiposity has been implicated as a risk factor for Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC), possibly promoting the progression from inflammation to metaplasia and neoplasia. We performed a systematic review and meta-analysis of studies to evaluate the association between central adiposity and erosive esophagitis (EE), BE, and EAC, specifically exploring body mass index (BMI)-independent and gastroesophageal reflux (GERD)-independent effects of central adiposity on the risk of these outcomes.

METHODS

We performed a systematic search of multiple databases through March 2013. Studies were included if they reported effect of central adiposity (visceral adipose tissue area, waist-hip ratio, and/or waist circumference) on the risk of EE, BE, and EAC. Summary adjusted odds ratio (aOR) estimates with 95% confidence intervals (CIs), comparing highest category of adiposity with the lowest category of adiposity, were calculated by using random-effects model.

RESULTS

Forty relevant articles were identified. Compared with patients with normal body habitus, patients with central adiposity had a higher risk of EE (19 studies; aOR, 1.87; 95% CI, 1.51-2.31) and BE (17 studies; aOR, 1.98; 95% CI, 1.52-2.57). The association between central adiposity and BE persisted after adjusting for BMI (5 studies; aOR, 1.88; 95% CI, 1.20-2.95). Reflux-independent association of central adiposity and BE was observed in studies that used GERD patients as controls or adjusted for GERD symptoms (11 studies; aOR, 2.04; 95% CI, 1.44-2.90). In 6 studies, central adiposity was associated with higher risk of EAC (aOR, 2.51; 95% CI, 1.54-4.06), compared with normal body habitus.

CONCLUSIONS

On the basis of a meta-analysis, central adiposity, independent of BMI, is associated with esophageal inflammation (EE), metaplasia (BE), and neoplasia (EAC). Its effects are mediated by reflux-dependent and reflux-independent mechanisms.

Association of Barrett's esophagus with type II Diabetes Mellitus: results from a large population-based case-control study

BACKGROUND & AIMS

Central obesity could increase the risk for Barrett's esophagus (BE) and esophageal adenocarcinoma by mechanical and/or metabolic mechanisms, such as hyperinsulinemia. We performed an epidemiologic study to determine whether prior type 2 diabetes mellitus (DM2) is associated with BE.

METHODS

We performed a population-based case-control study using the General Practice Research Database, a UK primary care database that contains information on more than 8 million subjects, to identify cases of BE (using previously validated codes; n = 14,245) and matched controls without BE (by age, sex, enrollment date, duration of follow-up evaluation, and practice region by incidence density sampling; n = 70,361). We assessed the association of a prior diagnosis of DM2 with BE using conditional univariate and multivariable regression analysis. Confounders assessed included smoking, obesity measured by body mass index (BMI), and gastroesophageal reflux disease.

RESULTS

BE cases were more likely than controls to have smoked (52.4% vs 49.9%), have a higher mean BMI (27.2 vs 26.9), and a higher prevalence of DM2 than controls (5.8% vs 5.3%). On multivariable analysis, DM2 was associated with a 49% increase in the risk of BE, independent of other known risk factors (odds ratio, 1.49; 95% confidence interval, 1.16-1.91). This association was stronger in women than men. Results remained stable with sensitivity analyses.

CONCLUSIONS

In a large population-based case-control study, DM2 was a risk factor for BE, independent of obesity (as measured by BMI) and other risk factors (smoking and gastroesophageal reflux disease). These data suggest that metabolic pathways related to DM2 should be explored in BE pathogenesis and esophageal carcinogenesis.