Influence of obesity on the risk of esophageal disorders

The Association Between Obesity and Malignant Progression of Barrett's Esophagus: A Systematic Review and Dose-Response Meta-Analysis

BACKGROUND AND AIMS

Obesity is a risk factor for both Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). However, it is unclear whether obesity drives the malignant progression of BE. We aimed to assess whether obesity is associated with high-grade dysplasia (HGD) or cancer in patients with BE.

METHODS

We searched MEDLINE and EMBASE from inception through April 2024 for studies reporting the effect of body mass index (BMI) on the progression of nondysplastic BE or low-grade dysplasia (LGD) to HGD or EAC. A 2-stage dose-response meta-analysis was performed to estimate the dose-response relationship between BMI with malignant progression. Study quality was appraised using a modified Newcastle-Ottawa scale.

RESULTS

Twenty studies reported data on 38,565 patients (74.4% male) in total, of whom 1684 patients were diagnosed with HGD/cancer. Nineteen studies were considered moderate to high quality. Eight cohort studies reported data on 6647 male patients with baseline nondysplastic BE/LGD, of whom 555 progressed to HGD/EAC (pooled annual rate of progression, 0.02%; 95% confidence interval [CI], 0.01%-0.03%), and 1992 female patients with baseline nondysplastic BE/LGD, with 110 progressors (pooled annual rate of progression, 0.01%; 95% CI, 0.01%-0.02%). There was no significant difference in pooled annual rate of progression between males and females (P = .15). Each 5-kg/m2 increase in BMI was associated with a 6% increase in the risk of malignant progression (adjusted odds ratio, 1.06; 95% CI, 1.02-1.10; P < .001; I2= 0%).

CONCLUSION

Our meta-analysis provides some evidence that obesity as measured by BMI is associated with malignant progression of BE with a dose-response relationship. This finding requires confirmation in future high-quality cohort studies. Future risk prediction models could incorporate measures of obesity to potentially improve risk stratification in patients with BE. PROSPERO, Number: CRD42017051046.

Metabolic syndrome and cancer risk: a two-sample Mendelian randomization study of European ancestry

BACKGROUND

The relationship between Metabolic Syndrome and cancer remains controversial. The authors aimed to assess the association between Metabolic Syndrome and cancer risk at different locations using a Mendelian randomization approach.

METHODS

The authors extracted single nucleotide polymorphisms (SNPs) of MetS and its components from public databases for populations of European ancestry. Causal effects were estimated using inverse variance weighting, MR-Egger, weighted median, and MR-PRESSO. Sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots. In addition, the authors calculated the Statistical power. Finally, the authors applied the False Discovery Rate (FDR) to correct our results.

RESULTS

IVW methods showed that Genetically predicted Metabolic Syndrome may be a potential risk factor for hepatocellular carcinoma ( P =0.031, P-FDR=0.093). Metabolic Syndrome was not causally associated with cancers at other sites (lung, thyroid, breast, prostate, kidney, bladder, colorectal, esophagus, and stomach). In further analyses, WC may increase the risk of lung ( P =0.003, P-FDR=0.018), and esophageal ( P =0.011, P-FDR=0.066) cancers and decrease the risk of prostate cancer ( P =0.006, P-FDR=0.001). Furthermore, hypertension may reduce the risk of Hepatic cancer ( P =0.014, P-FDR=0.084).

CONCLUSION

Our study suggests that genetically predicted Metabolic Syndrome may increase the risk of some cancers. Prevention and treatment of Metabolic Syndrome may help to prevent the development of related cancers.

Integration of observational and causal evidence for the association between adiposity and 17 gastrointestinal outcomes: An umbrella review and meta-analysis

We systematically reviewed observational and Mendelian randomization (MR) articles that evaluated the association between obesity and 17 gastrointestinal (GI) diseases to integrate causal and observational evidence. A total of 594 observational studies from 26 systematic reviews and meta-analyses and nine MR articles were included. For every 5 kg/m2 increase in body mass index (BMI), there was an increased risk of GI diseases ranging from 2% for rectal cancer (relative risk [RR]: 1.02, 95% confidence interval [CI]: 1.01 to 1.03) to 63% for gallbladder disease (RR: 1.63, 95% CI: 1.50 to 1.77). MR articles indicated that risks of developing GI diseases elevated with each 1 standard deviation increase in genetically predicted BMI, ranging from 11% for Crohn's disease to 189% for nonalcoholic fatty liver disease. Moreover, upper GI conditions were less susceptible, whereas hepatobiliary organs were more vulnerable to increased adiposity. Among the associations between obesity and the 17 GI conditions, causal relationships were inferred from only approximately half (10/17, 59%). This study reveals a substantial gap between observational and causal evidence, indicating that a combined approach is necessary to effectively inform public health policies and guide epidemiological research on obesity and GI diseases.

The Economic Impact of Introducing RefluxStop for Refractory Gastroesophageal Reflux Disease on the Italian Healthcare System

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a common ailment associated with troublesome symptoms. The standard of care in Italy involves initial treatment with proton pump inhibitor (PPI)-based medical management or laparoscopic Nissen fundoplication (LNF) for patients unwilling to continue or intolerant of long-term PPI therapy. RefluxStop is a novel medical device, intended for laparoscopic implantation, that has recently proven to be an efficacious and cost-effective treatment option for patients with GERD. This analysis aims to describe the short-term budget impact of introducing RefluxStop as a GERD treatment option within the Italian National Health Service (SSN).

METHODS

A model adherent to international best practice recommendations was developed to estimate the budget impact of introducing RefluxStop over a 5-year time horizon. Two scenarios were considered: one without RefluxStop (i.e., comprising PPI therapy, LNF, and magnetic sphincter augmentation using the LINX system); and one with RefluxStop (i.e., addition of RefluxStop to the three treatment options previously mentioned). Clinical benefits and costs associated with each intervention were included in the analysis.

RESULTS

Over 5 years, the introduction of RefluxStop resulted in avoidance of 95 surgical failures, 11 reoperations, and 64 endoscopic esophageal dilations. Introduction of RefluxStop resulted in an almost neutral impact on the existing budget with a 0.316% increase in the annual Italian SSN spending on GERD treatment.

CONCLUSION

Introduction of RefluxStop as a GERD treatment option in Italy is likely to be associated with substantial clinical benefits and a marginal budget impact.

Genetically predicted 486 blood metabolites in relation to risk of esophageal cancer: a Mendelian randomization study

Background and Objective

Enhancing therapy choices for varying stages of esophageal cancer and improving patient survival depend on timely and precise diagnosis. Blood metabolites may play a role in either causing or preventing esophageal cancer, but further research is needed to determine whether blood metabolites constitute a genetic risk factor for the disease. In order to tackle these problems, we evaluated the causal association between esophageal cancer and 486 blood metabolites that functioned as genetic proxies using a two-sample Mendelian randomization (MR) study.

Methods

We utilized two-sample MR analyses to evaluate the causal links between blood metabolites and esophageal cancer. For the exposure, we used a genome-wide association study (GWAS) of 486 metabolites, and a GWAS study on esophageal cancer from Sakaue et al. was used for preliminary analyses. Causal analyses employed randomized inverse variance weighted (IVW) as the main method, supplemented by MR-Egger and weighted median (WM) analyses. Sensitivity analyses included the MR-Egger intercept test, Cochran Q test, MR-PRESSO, and leave-one-out analysis. Additionally, independent esophageal cancer GWAS data were utilized for replication and meta-analysis. FDR correction was applied to discern features with causal relationships. For conclusive metabolite identification, we conducted Steiger tests, linkage disequilibrium score regression, and colocalization analyses. Moreover, we utilized the program MetaboAnalyst 5.0 to analyze metabolic pathways.

Results

This study found an important association between esophageal cancer and three metabolites: 1-linoleoylglycerophosphoethanolamine* [odds ratio (OR) = 3.21, 95% confidence interval (CI): 1.42-7.26, p < 0.01], pyroglutamine* (OR = 1.92, 95% CI: 1.17-3.17, p < 0.01), and laurate (12:0) (OR = 3.06, 95% CI: 1.38-6.78, p < 0.01).

Conclusion

This study establishes a causal link between three defined blood metabolites and esophageal cancer, offering fresh insights into its pathogenesis.

Cholelithiasis and cholecystectomy increase the risk of gastroesophageal reflux disease and Barrett's esophagus

Background

Cholelithiasis or cholecystectomy may contribute to the development of gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) through bile reflux; however, current observational studies yield inconsistent findings. We utilized a novel approach combining meta-analysis and Mendelian randomization (MR) analysis, to assess the association between them.

Methods

The literature search was done using PubMed, Web of Science, and Embase databases, up to 3 November 2023. A meta-analysis of observational studies assessing the correlations between cholelithiasis or cholecystectomy, and the risk factors for GERD, BE, and EACwas conducted. In addition, the MR analysis was employed to assess the causative impact of genetic pre-disposition for cholelithiasis or cholecystectomy on these esophageal diseases.

Results

The results of the meta-analysis indicated that cholelithiasis was significantly linked to an elevated risk in the incidence of BE (RR, 1.77; 95% CI, 1.37-2.29; p < 0.001) and cholecystectomy was a risk factor for GERD (RR, 1.37; 95%CI, 1.09-1.72; p = 0.008). We observed significant genetic associations between cholelithiasis and both GERD (OR, 1.06; 95% CI, 1.02-1.10; p < 0.001) and BE (OR, 1.21; 95% CI, 1.11-1.32; p < 0.001), and a correlation between cholecystectomy and both GERD (OR, 1.04; 95% CI, 1.02-1.06; p < 0.001) and BE (OR, 1.13; 95% CI, 1.06-1.19; p < 0.001). After adjusting for common risk factors, such as smoking, alcohol consumption, and BMI in multivariate analysis, the risk of GERD and BE still persisted.

Conclusion

Our study revealed that both cholelithiasis and cholecystectomy elevate the risk of GERD and BE. However, there is no observed increase in the risk of EAC, despite GERD and BE being the primary pathophysiological pathways leading to EAC. Therefore, patients with cholelithiasis and cholecystectomy should be vigilant regarding esophageal symptoms; however, invasive EAC cytology may not be necessary.

Causal effects of genetic birth weight and gestational age on adult esophageal diseases: Mendelian randomization study

BACKGROUND

Few studies have investigated the association between gestational age, birth weight, and esophageal cancer risk; however, causality remains debated. We aimed to establish causal links between genetic gestational age and birth weight traits and gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and esophageal adenocarcinoma (EA). Additionally, we explored if known risk factors mediate these links.

AIM

To analyze of the relationship between gestational age, birth weight and GERD, BE, and EA.

METHODS

Genetic data on gestational age and birth weight (n = 84689 and 143677) from the Early Growth Genetics Consortium and outcomes for GERD (n = 467253), BE (n = 56429), and EA (n = 21271) from genome-wide association study served as instrumental variables. Mendelian randomization (MR) and mediation analyses were conducted using MR-Egger, weighted median, and inverse variance weighted methods. Robustness was ensured through heterogeneity, pleiotropy tests, and sensitivity analyses.

RESULTS

Birth weight was negatively correlated with GERD and BE risk [odds ratio (OR) = 0.78; 95% confidence interval (CI): 0.69-0.8] and (OR = 0.75; 95%CI: 0.60-0.9), respectively, with no significant association with EA. No causal link was found between gestational age and outcomes. Birth weight was positively correlated with five risk factors: Educational attainment (OR = 1.15; 95%CI: 1.01-1.31), body mass index (OR = 1.06; 95%CI: 1.02-1.1), height (OR = 1.12; 95%CI: 1.06-1.19), weight (OR = 1.13; 95%CI: 1.10-1.1), and alcoholic drinks per week (OR = 1.03; 95%CI: 1.00-1.06). Mediation analysis showed educational attainment and height mediated the birth weight-BE link by 13.99% and 5.46%.

CONCLUSION

Our study supports the protective role of genetically predicted birth weight against GERD, BE, and EA, independent of gestational age and partially mediated by educational attainment and height.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

25 year trends in cancer incidence and mortality among adults aged 35-69 years in the UK, 1993-2018: retrospective secondary analysis

OBJECTIVE

To examine and interpret trends in UK cancer incidence and mortality for all cancers combined and for the most common cancer sites in adults aged 35-69 years.

DESIGN

Retrospective secondary data analysis.

DATA SOURCES

Cancer registration data, cancer mortality and national population data from the Office for National Statistics, Public Health Wales, Public Health Scotland, Northern Ireland Cancer Registry, NHS England, and the General Register Office for Northern Ireland.

SETTING

23 cancer sites were included in the analysis in the UK.

PARTICIPANTS

Men and women aged 35-69 years diagnosed with or who died from cancer between 1993 to 2018.

MAIN OUTCOME MEASURES

Change in cancer incidence and mortality age standardised rates over time.

RESULTS

The number of cancer cases in this age range rose by 57% for men (from 55 014 cases registered in 1993 to 86 297 in 2018) and by 48% for women (60 187 to 88 970) with age standardised rates showing average annual increases of 0.8% in both sexes. The increase in incidence was predominantly driven by increases in prostate (male) and breast (female) cancers. Without these two sites, all cancer trends in age standardised incidence rates were relatively stable. Trends for a small number of less common cancers showed concerning increases in incidence rates, for example, in melanoma skin, liver, oral, and kidney cancers. The number of cancer deaths decreased over the 25 year period, by 20% in men (from 32 878 to 26 322) and 17% in women (28 516 to 23 719); age standardised mortality rates reduced for all cancers combined by 37% in men (-2.0% per year) and 33% in women (-1.6% per year). The largest decreases in mortality were noted for stomach, mesothelioma, and bladder cancers in men and stomach and cervical cancers and non-Hodgkin lymphoma in women. Most incidence and mortality changes were statistically significant even when the size of change was relatively small.

CONCLUSIONS

Cancer mortality had a substantial reduction during the past 25 years in both men and women aged 35-69 years. This decline is likely a reflection of the successes in cancer prevention (eg, smoking prevention policies and cessation programmes), earlier detection (eg, screening programmes) and improved diagnostic tests, and more effective treatment. By contrast, increased prevalence of non-smoking risk factors are the likely cause of the observed increased incidence for a small number of specific cancers. This analysis also provides a benchmark for the following decade, which will include the impact of covid-19 on cancer incidence and outcomes.

Adiposity and risk of oesophageal cancer subtypes in the Million Women Study

BACKGROUND

The strong association of body mass index (BMI) with increased oesophageal adenocarcinoma risk is established, but its relationship with oesophageal squamous cell carcinoma is less clear. There is little evidence regarding the association of abdominal adiposity with either subtype.

METHODS

In a large prospective cohort of women in the UK, mean age 56.2 [standard deviation (SD) = 4.9] years, we investigated the risk of oesophageal adenocarcinoma and squamous cell carcinoma in relation to self-reported BMI, waist circumference (WC) and waist-hip ratio (WHR), using Cox regression to estimate adjusted relative risks (RR) and 95% confidence intervals (CIs), taking account of potential reverse causation bias.

RESULTS

During mean follow-up of 17.7 (SD = 4.9) years, 1386 adenocarcinomas and 1799 squamous cell carcinomas of the oesophagus were registered among 1 255 529 women. Compared with women of BMI 22.5 to <25 kg/m2, those with BMI ≥35 kg/m2 had a 2.5-fold risk of adenocarcinoma (adjusted RR = 2.46, 95% CI = 1.99-3.05) and an almost 70% reduction in risk of squamous cell carcinoma (RR = 0.32, 95% CI = 0.22-0.46). These associations were broadly similar in each 5-year follow-up period, and were evident in both never and ever smokers, although somewhat stronger for squamous cell carcinoma among current and past smokers than in never smokers (Pheterogeneity = 0.007). After controlling for BMI, WC and WHR were associated with risk of squamous cell carcinoma but not adenocarcinoma.

CONCLUSIONS

In this population of middle-aged women, there was robust evidence that greater BMI is associated with an increased risk of oesophageal adenocarcinoma and a reduced risk of squamous cell carcinoma.

Causal association of gut microbiota and esophageal cancer: a Mendelian randomization study

Introduction

Despite the growing body of evidence, the link between the gut microbiota and different types of tumors, such as colorectal, gastric, and liver cancer, is becoming more apparent. The gut microbiota can be used as a reference for evaluating various diseases, including cancer, and can also act as risk factors or preventive factors. However, the specific connection between the gut microbiota and the advancement of esophageal cancer has yet to be investigated. Therefore, the aim of this research is to clarify the possible causal influence of intestinal microorganisms on the vulnerability to esophageal cancer through the utilization of Mendelian randomization (MR) studies.

Methods

In this study, we employed a two-sample Mendelian randomization approach to evaluate the unbiased causal association between 150 different gut microbiota types and the occurrence of esophageal cancer. Following the selection from the IEU GWAS database and SNP filtration, we utilized various MR statistical techniques on the suitable instrumental variables. These included IVW methods, employing inverse variance weighting. Additionally, we performed a range of sensitivity analyses to confirm the heterogeneity and pleiotropy of the instrumental variables, thus ensuring the reliability of the outcomes.

Results

The increased likelihood of developing esophageal cancer is linked to the genetically predicted high levels of Gordonibacter, Oxalobacter, Coprobacter, Veillonella, Ruminiclostridium 5, Ruminococcus 1, and Senegalimasilia genera. Conversely, a decreased risk of esophageal cancer is associated with the high abundance of Turicibacter, Eubacterium oxidoreducens group, Romboutsia, and Prevotella 9 genera. No heterogeneity and pleiotropy were detected in the sensitivity analysis.

Discussion

We found that 11 types of gut microbial communities are associated with esophageal cancer, thereby confirming that the gut microbiota plays a significant role in the path.

Mediterranean diet and olive oil, microbiota, and obesity-related cancers. From mechanisms to prevention

Olive oil (OO) is the main source of added fat in the Mediterranean diet (MD). It is a mix of bioactive compounds, including monounsaturated fatty acids, phytosterols, simple phenols, secoiridoids, flavonoids, and terpenoids. There is a growing body of evidence that MD and OO improve obesity-related factors. In addition, obesity has been associated with an increased risk for several cancers: endometrial, oesophageal adenocarcinoma, renal, pancreatic, hepatocellular, gastric cardia, meningioma, multiple myeloma, colorectal, postmenopausal breast, ovarian, gallbladder, and thyroid cancer. However, the epidemiological evidence linking MD and OO with these obesity-related cancers, and their potential mechanisms of action, especially those involving the gut microbiota, are not clearly described or understood. The goals of this review are 1) to update the current epidemiological knowledge on the associations between MD and OO consumption and obesity-related cancers, 2) to identify the gut microbiota mechanisms involved in obesity-related cancers, and 3) to report the effects of MD and OO on these mechanisms.

Body mass index and esophageal and gastric cancer: A pooled analysis of 10 population-based cohort studies in Japan

The effect of body mass index (BMI) on esophageal and gastric carcinogenesis might be heterogeneous, depending on subtype or subsite. However, findings from prospective evaluations of BMI associated with these cancers among Asian populations have been inconsistent and limited, especially for esophageal adenocarcinoma and gastric cardia cancer. We performed a pooled analysis of 10 population-based cohort studies to examine this association in 394,247 Japanese individuals. We used Cox proportional hazards regression to estimate study-specific hazard ratios (HRs) and 95% confidence intervals (CIs), then pooled these estimates to calculate summary HRs with a random effects model. During 5,750,107 person-years of follow-up, 1569 esophageal cancer (1038 squamous cell carcinoma and 86 adenocarcinoma) and 11,095 gastric (728 cardia and 5620 noncardia) cancer incident cases were identified. An inverse association was observed between BMI and esophageal squamous cell carcinoma (HR per 5-kg/m2 increase 0.57, 95% CI 0.50-0.65), whereas a positive association was seen in gastric cardia cancer (HR 1.15, 95% CI 1.00-1.32). A nonsignificant and significant positive association for overweight or obese (BMI ≥25 kg/m2 ) relative to BMI <25 kg/m2 was observed with esophageal adenocarcinoma (HR 1.32, 95% CI 0.80-2.17) and gastric cardia cancer (HR 1.24, 95% CI 1.05-1.46), respectively. No clear association with BMI was found for gastric noncardia cancer. This prospective study-the largest in an Asian country-provides a comprehensive quantitative estimate of the association of BMI with upper gastrointestinal cancer and confirms the subtype- or subsite-specific carcinogenic impact of BMI in a Japanese population.

Turnkey algorithmic approach for the evaluation of gastroesophageal reflux disease after bariatric surgery

Bariatric surgeries are often complicated by de-novo gastroesophageal reflux disease (GERD) or worsening of pre-existing GERD. The growing rates of obesity and bariatric surgeries worldwide are paralleled by an increase in the number of patients requiring post-surgical GERD evaluation. However, there is currently no standardized approach for the assessment of GERD in these patients. In this review, we delineate the relationship between GERD and the most common bariatric surgeries: sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), with a focus on pathophysiology, objective assessment, and underlying anatomical and motility disturbances. We suggest a stepwise algorithm to help diagnose GERD after SG and RYGB, determine the underlying cause, and guide the management and treatment.

Body shape phenotypes of multiple anthropometric traits and cancer risk: a multi-national cohort study

BACKGROUND

Classical anthropometric traits may fail to fully represent the relationship of weight, adiposity, and height with cancer risk. We investigated the associations of body shape phenotypes with the risk of overall and site-specific cancers.

METHODS

We derived four distinct body shape phenotypes from principal component (PC) analysis on height, weight, body mass index (BMI), waist (WC) and hip circumferences (HC), and waist-to-hip ratio (WHR). The study included 340,152 men and women from 9 European countries, aged mostly 35-65 years at recruitment (1990-2000) in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 15.3 years, 47,110 incident cancer cases were recorded. PC1 (overall adiposity) was positively associated with the risk of overall cancer, with a HR per 1 standard deviation (SD) increment equal to 1.07 (95% confidence interval 1.05 to 1.08). Positive associations were observed with 10 cancer types, with HRs (per 1 SD) ranging from 1.36 (1.30-1.42) for endometrial cancer to 1.08 (1.03-1.13) for rectal cancer. PC2 (tall stature with low WHR) was positively associated with the risk of overall cancer (1.03; 1.02-1.04) and five cancer types which were not associated with PC1. PC3 (tall stature with high WHR) was positively associated with the risk of overall cancer (1.04; 1.03-1.05) and 12 cancer types. PC4 (high BMI and weight with low WC and HC) was not associated with overall risk of cancer (1.00; 0.99-1.01).

CONCLUSIONS

In this multi-national study, distinct body shape phenotypes were positively associated with the incidence of 17 different cancers and overall cancer.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Sleep traits, fat accumulation, and glycemic traits in relation to gastroesophageal reflux disease: A Mendelian randomization study

Background

Sleep traits, fat accumulation, and glycemic traits are associated with gastroesophageal reflux disease (GERD) in observational studies. However, whether their associations are causal remains unknown. We performed a Mendelian randomization (MR) study to determine these causal relationships.

Methods

Independent genetic variants associated with insomnia, sleep duration, short sleep duration, body fat percentage, visceral adipose tissue (VAT) mass, type 2 diabetes, fasting glucose, and fasting insulin at the genome-wide significance level were selected as instrumental variables. Summary-level data for GERD were derived from a genome-wide association meta-analysis including 78,707 cases and 288,734 controls of European descent. Inverse variance weighted (IVW) was used for the main analysis, with weighted median and MR-Egger as complements to IVW. Sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis to estimate the stability of the results.

Results

The MR study showed the causal relationships of genetically predicted insomnia (odds ratio [OR] = 1.306, 95% confidence interval [CI] 1.261 to 1.352; p = 2.24 × 10^-51), short sleep duration (OR = 1.304, 95% CI: 1.147 to 1.483, p = 4.83 × 10^-5), body fat percentage (OR = 1.793, 95% CI 1.496 to 2.149; p = 2.68 × 10^-10), and visceral adipose tissue (OR = 2.090, 95% CI 1.963 to 2.225; p = 4.42 × 10^-117) with the risk of GERD. There was little evidence for causal associations between genetically predicted glycemic traits and GERD. In multivariable analyses, genetically predicted VAT accumulation, insomnia, and decreased sleep duration were associated with an increased risk of GERD.

Conclusion

This study suggests the possible roles of insomnia, short sleep, body fat percentage, and visceral adiposity in the development of GERD.

Esophageal cancer and bacterial part of gut microbiota - A multidisciplinary point of view

There is an urgent need to search for new screening methods that allow early detection of esophageal cancer and thus achieve better clinical outcomes. Nowadays, it is known that the esophagus is not a sterile part of the gastrointestinal tract. It is colonized with various microorganisms therefore a "healthy" esophageal microbiome exists. The dysbiotic changes of esophageal microbiome can lead to the development of esophageal diseases including esophageal cancer. There is a strong consensus in the literature that the intestinal microbiome may be involved in esophageal carcinogenesis. Recently, emphasis has also been placed on the relationship between the oral microbiome and the occurrence of esophageal cancer. According to recent studies, some of the bacteria present in the oral cavity, such as Tannerella forsythia, Streptococcus anginosus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum may contribute to the development of this cancer. Moreover, the oral microbiome of patients with esophageal cancer differs significantly from that of healthy individuals. This opens new insights into the search for a microbiome-associated marker for early identification of patients at high risk for developing this cancer.

The effects of prehabilitation on body composition in patients undergoing multimodal therapy for esophageal cancer

Prehabilitation aims to optimize a patient's functional capacity in preparation for surgery. Esophageal cancer patients have a high incidence of sarcopenia and commonly undergo neoadjuvant therapy, which is associated with loss of muscle mass. This study examines the effects of prehabilitation on body composition during neoadjuvant therapy in esophageal cancer patients. In this cohort study, changes in body composition were compared between esophageal cancer patients who participated in prehabilitation during neoadjuvant therapy and controls who did not receive prehabilitation. Assessment of body composition was performed from CT images acquired at the time of diagnosis and after neoadjuvant therapy. Fifty-one prehabilitation patients and 28 control patients were identified. There was a significantly greater fall in skeletal muscle index (SMI) in the control group compared with the prehabilitation patients (Δ SMI mean difference = -2.2 cm2/m2, 95% CI -4.3 to -0.1, p=0.038). Within the prehabilitation cohort, there was a smaller decline in SMI in patients with ≥75% adherence to exercise in comparison to those with lower adherence (Δ SMI mean difference = -3.2, 95% CI -6.0 to -0.5, P = 0.023). A greater decrease in visceral adipose tissue (VAT) was seen with increasing volumes of exercise completed during prehabilitation (P = 0.046). Loss of VAT during neoadjuvant therapy was associated with a lower risk of post-operative complications (P = 0.017). By limiting the fall in SMI and promoting VAT loss, prehabilitation may have multiple beneficial effects in patients with esophageal cancer. Multi-center, randomized studies are needed to further explore these findings.

Metabolic syndrome is associated with higher rate of gastroesophageal reflux disease: a meta-analysis

BACKGROUND AND AIM

Gastroesophageal reflux disease (GERD) seriously lowers the quality of life of patients, and its prevalence has gradually increased in recent years. Some studies have showed that metabolic syndrome (MetS) is related to GERD, but the results remain controversial. This study explored the relationship between MetS and GERD through systematic retrieval and analysis of published studies.

METHODS

Retrieve related research from PubMed, Web of Science, and Cochrane Library. Including cohort studies that compare the prevalence of GERD between patients with MetS and patients without, and case-control studies or cross-sectional studies that compare the prevalence of MetS between patients with GERD and patients without. In addition to analyzing the relationship between MetS and GERD, individual metabolic components are also analyzed. Use a random effects model (DerSimmonian and Laird) to merge the odd ratio (OR). Cochran's Q test and Higgins' I-squared statistic were performed to assess heterogeneity. Publication bias was assessed by Egger's test.

KEY RESULTS

A total of 103,048 patients from 15 studies were included. The combined results suggest that MetS is a risk factor of GERD (OR: 1.66, 95%CI: 1.38-1.99). Among the individual metabolic components, abdominal obesity (OR: 1.42, 95%CI: 1.22-1.64), hypertriglyceridemia (OR: 1.50, 95%CI: 1.27-1.78), hyperglycemia (OR: 1.31, 95%CI: 1.07-1.61), and hypertension (OR: 1.19, 95%CI: 1.07-1.33) are risk factors of GERD.

CONCLUSIONS AND INFERENCES

MetS is a risk factor of GERD, and among the abnormal metabolic components that establish the diagnosis of MetS, abdominal obesity, hypertriglyceridemia, hyperglycemia, and hypertension are risk factors of GERD.

Role of Obesity, Physical Exercise, Adipose Tissue-Skeletal Muscle Crosstalk and Molecular Advances in Barrett's Esophagus and Esophageal Adenocarcinoma

Both obesity and esophageal adenocarcinoma (EAC) rates have increased sharply in the United States and Western Europe in recent years. EAC is a classic example of obesity-related cancer where the risk of EAC increases with increasing body mass index. Pathologically altered visceral fat in obesity appears to play a key role in this process. Visceral obesity may promote EAC by directly affecting gastroesophageal reflux disease and Barrett’s esophagus (BE), as well as a less reflux-dependent effect, including the release of pro-inflammatory adipokines and insulin resistance. Deregulation of adipokine production, such as the shift to an increased amount of leptin relative to “protective” adiponectin, has been implicated in the pathogenesis of BE and EAC. This review discusses not only the epidemiology and pathophysiology of obesity in BE and EAC, but also molecular alterations at the level of mRNA and proteins associated with these esophageal pathologies and the potential role of adipokines and myokines in these disorders. Particular attention is given to discussing the possible crosstalk of adipokines and myokines during exercise. It is concluded that lifestyle interventions to increase regular physical activity could be helpful as a promising strategy for preventing the development of BE and EAC.

Trends and projections in the incidence of oesophageal cancer in the Netherlands: An age-period-cohort analysis from 1989 to 2041

In Western populations, the incidence of oesophageal squamous cell carcinoma (OSCC) has been declining, whereas the incidence of oesophageal adenocarcinoma (OAC) has been increasing. Our study examines temporal trends in the incidence of oesophageal cancer in the Netherlands between 1989 and 2016, in addition to predicting future trends through 2041. Data from the Netherlands Cancer Registry and Statistics Netherlands were collected to obtain incidence trends of OSCC and OAC for the period 1989 to 2016. Age‐period‐cohort (APC) modelling was used to estimate the contribution of age, calendar period and birth cohort on the observed incidence trends. To predict the future numbers of new cases of both OSCC and OAC from 2017 to 2041, log‐linear APC models were fitted to the trends of 1989 to 2016. The age‐standardised incidence rates of OSCC have decreased slightly for men and increased slightly for women. In contrast, a marked increase in the incidence of OAC was observed, ranging from 2.8 per 100 000 persons in 1989 to 10.1 in 2016. This increase in OAC incidence was more prominent in men, and it will result in an increased risk of OAC for successive generations. Future projections indicate that the incidence of OAC will further increase to 13.1 per 100 000 persons in 2037 to 2041, meaning that there will be 13 259 cases of OAC in 2037 to 2041, as compared to 9386 diagnoses in 2017 to 2021. The changing epidemiologic trends in oesophageal cancer in the Netherlands should be reflected in the development of prevention, early detection and treatment strategies.

What's new?

The incidence of esophageal adenocarcinoma (OAC) is on the rise in Western countries. Better understanding of this trend could facilitate critical improvements in OAC prevention, early detection, and treatment strategies. Here, the authors investigated trends in OAC incidence from 1989 to 2016 for successive birth cohorts in the Netherlands. OAC incidence was found to have increased significantly since 1989, with risk rising most noticeably in men. Analyses through 2037‐2041 predict continued growth in OAC cases. The findings highlight the importance of promoting measures to prevent esophageal cancer, particularly those aimed at controlling modifiable risk factors, such as obesity and smoking.

Influence of gastric morphology on gastroesophageal reflux in adults: An observational study

The study's aim was to determine if there was an association between gastric morphology and gastroesophageal reflux (GER). Few published studies have investigated the relationship between gastric morphology and the risk of GER.A total of 777 patients were randomly selected from 3000 to 3300 patients who presented at a medical center in Taipei for annual health checkups from early 2008 through to late 2010 and underwent a series of radiographs of the upper gastrointestinal tract (UGI). GER was recorded during the real-time fluoroscopic study. Thirty-nine participants had a follow-up endoscopy, and another 164 participants were followed up by a second UGI series 12 +/ -1.5 months later, from late 2008 through to early 2022. All participants completed a lifestyle and symptom questionnaire. The variables included current smoking and alcohol consumption. Participants who had heartburn and dysphagia were included in the study. Additionally, all participants underwent a limited physical examination which recorded age, sex, body mass index, and total cholesterol and triglyceride levels.All participants were classified into types 1 to 6 based on the gastric morphology determined from the first UGI. Cascade stomach is recognized by characteristic findings on UGI. Gastric types 2 and 3 tend to appear as cascade stomachs and were significantly associated with GER (P < .05) compared with the other groups. Morphologic type 5 appeared as an elongated sac extending downward into the pelvic cavity and was less likely to develop GER (P < .001). The results of follow-up studies by UGI and endoscopy were similar to those of the first UGI. Gastric morphologic type 2 was significantly associated, and type 5 was usually not associated, with GER and erosive esophagitis (P < .05) compared with the other groups, by both UGI and endoscopy.Gastric morphologic types 2 and 3, with cascade stomach, might provide a relatively easy method for the development of the GER phenomenon. Gastric morphologic type 5 appeared as an elongated sac that might reduce the incidence of the GER phenomenon. The study suggested that gastric morphologic type could influence the occurrence of GER.

ESOPHAGEAL FUNCTIONAL DISORDERS IN THE PRE-OPERATORY EVALUATION OF BARIATRIC SURGERY

BACKGROUND

Obesity is an independent risk factor for esophageal symptoms, gastroesophageal reflux disease (GERD), and motor abnormalities. When contemplating bariatric surgery, patients with obesity type III undergo esophagogastroduodenoscopy (EGD) and also esophageal manometry (EMN), and prolonged pHmetry (PHM) as part of their pre-operative evaluation.

OBJECTIVE

Description of endoscopy, manometry and pHmetry findings in patients with obesity type III preparing for bariatric surgery, and correlation of these findings with the presence of typical GERD symptoms.

METHODS

Retrospective study in which clinical symptoms of GERD were assessed, focusing on the presence of heartburn and regurgitation. All patients underwent EMN, PHM and most of them EGD.

RESULTS

114 patients (93 females-81%), average age 36 years old, average BMI of 45.3, were studied. Typical GERD symptoms were referred by 43 (38%) patients while 71 (62%) were asymptomatic. Eighty two patients (72% of total) underwent EGD and 36 (42%) evidenced esophageal abnormalities. Among the abnormal findings, hiatal hernia was seen in 36%, erosive esophagitis (EE) in 36%, and HH+EE in 28%. An abnormal EMN was recorded in 51/114 patients (45%). The main abnormality was a hypotensive lower esophageal sphincter (LES) in 32%, followed by ineffective esophageal motility in 25%, nutcracker esophagus in 19%, IEM + hypotensive LES in 10%, intra-thoracic LES (6%), hypertensive LES (4%), aperistalsis (2%) and achalasia (2%). Among the 43 symptomatic patients, 23 (53%) had abnormal EMN and 31/71 asymptomatic cases (44%) also presented this finding (P=0.30). PHM showed abnormal reflux in 60/114 patients (53%), with a predominance of bi-positional reflux (42%), followed by supine reflux (33%) and upright reflux (25%). Abnormal PHM was found in 26/43 symptomatic cases (60%) and also among 34/71 asymptomatic cases (48%) (P=0.19).

CONCLUSION

Manometric abnormalities were common in obesity type III patients, the most frequent being hypotensive LES, followed by IEM. Most patients were asymptomatic. There was no correlation between the finding of motor abnormalities and the presence of symptoms. More than half the patients had abnormal reflux at PHM. We found no significant correlation between abnormal reflux and the presence of symptoms.

Lipid droplet biogenesis and COX-2 pathway activation are triggered by Barrett's esophagus and adenocarcinoma, but not esophageal squamous cell carcinoma risk factors

Esophageal cancer (EC) is an aggressive disease, presenting two main histological subtypes: adenocarcinoma (EAC) and squamous cell carcinoma (ESCC). The two EC subtypes widely differ concerning virtually all factors. ESCC development is mainly associated with tobacco and alcohol abuse, whereas obesity and chronic gastroesophageal reflux disease (GERD) are important risk factors not only for EAC, but also for for Barrett’s esophagus (BE), an intestinal metaplasia that precedes EAC. Obesity triggers ectopic lipid droplets (LD) accumulation in non-adipose tissues. LD are organelles involved in cell metabolism, signaling, proliferation and production of inflammatory mediators. Therefore, the aim of this work was to investigate LD occurrence and role in EC. This study shows progressive LD levels increase along EAC development, in esophageal samples from non-obese through obese individuals, as well as BE, and EAC patients, whereas no significant changes were observed in ESCC samples, when compared to non-tumor samples. Additionally, in order to mimic BE and EAC risk factors exposure, a non-tumor esophageal cell line was incubated with oleic acid (OA) and acidified medium and/or deoxycholic acid (DCA), revealing a significant increment in LD amount as well as in COX-2 and CXCL-8 expression, and in IL-8 secretion. Further, COX-2 expression and LD amount presented a significant positive correlation and were detected co-localized in EAC, but not in ESCC, suggesting that LD may be the site for eicosanoid production in EAC. In conclusion, this study shows that obesity, and BE- and EAC-associated inflammatory stimuli result in a gradual increase of LD, that may be responsible for orchestrating inflammatory mediators’ production and/or action, thus contributing to BE and EAC genesis and progression.

Global Burden, Risk Factors, and Trends of Esophageal Cancer: An Analysis of Cancer Registries from 48 Countries

Simple Summary

Esophageal cancer is the seventh most common cancer globally. Preventive measures and clinical management differ based on histologic subtype. However, information has been lacking on its most recent patterns according to histological subtype, associated risk factors, and epidemiological trends on a global scale. This study is a global analysis of the incidence/mortality trends of esophageal cancer in more than 48 countries/regions based on high quality population-based registries. We conclude that adenocarcinoma has already surpassed squamous cell carcinoma as the most frequent type of esophageal cancer in some western countries and is expected to increase in other countries. It is important to closely monitor and slow down the growing rates of obesity and metabolic syndrome, which are the important risk factors for adenocarcinoma. With the development of more advanced and less invasive technology, population-based targeted screening endoscopy would be recommended for high-risk individuals.

Abstract

This study aimed to examine the global burden, risk factors, and trends of esophageal cancer based on age, sex, and histological subtype. The data were retrieved from cancer registries database from 48 countries in the period 1980–2017. Temporal patterns of incidence and mortality were evaluated by average annual percent change (AAPC) using joinpoint regression. Associations with risk factors were examined by linear regression. The highest incidence of esophageal cancer was observed in Eastern Asia. The highest incidence of adenocarcinoma (AC) was found in the Netherlands, the United Kingdom, and Ireland. A higher AC/squamous cell carcinoma (SCC) incidence ratio was associated with a higher prevalence of obesity and elevated cholesterol. We observed an incidence increase (including AC and SCC) in some countries, with the Czech Republic (female: AAPC 4.66), Spain (female: 3.41), Norway (male: 3.10), Japan (female: 2.18), Thailand (male: 2.17), the Netherlands (male: 2.11; female: 1.88), and Canada (male: 1.51) showing the most significant increase. Countries with increasing mortality included Thailand (male: 5.24), Austria (female: 3.67), Latvia (male: 2.33), and Portugal (male: 1.12). Although the incidence of esophageal cancer showed an overall decreasing trend, an increasing trend was observed in some countries with high AC/SCC incidence ratios. More preventive measures are needed for these countries.

Microbiome of the Aerodigestive Tract in Health and Esophageal Disease

The diverse human gut microbiome is comprised of approximately 40 trillion microorganisms representing up to 1000 different bacterial species. The human microbiome plays a critical role in gut epithelial health and disease susceptibility. While the interaction between gut microbiome and gastrointestinal pathology is increasingly understood, less is known about the interaction between the microbiome and the aerodigestive tract. This review of the microbiome of the aerodigestive tract in health, and alterations in microbiome across esophageal pathologies highlights important findings and areas for future research. First, microbiome profiles are distinct along the aerodigestive tract, spanning the oral cavity to the stomach. In patients with reflux-related disease such as gastro-esophageal reflux disease, Barrett's esophagus, and esophageal adenocarcinoma, investigators have observed an overall increase in gram negative bacteria in the esophageal microbiome compared to healthy individuals. However, whether differences in microbiome promote disease development, or if these shifts are a consequence of disease remains unknown. Interestingly, use of proton pump inhibitor therapy is also associated with shifts in the microbiome, with distinct shifts and patterns along the aerodigestive tract. The relationship between the human gut microbiome and esophageal pathology is a ripe area for investigation, and further understanding of these pathways may promote development of novel targets in prevention and therapy for esophageal diseases.

Gender-Specific Risk Factors for Reflux Esophagitis in a Predominantly Hispanic Population of a Large Safety-Net Hospital

BACKGROUND

Defining factors associated with severe reflux esophagitis allows for identification of subgroups most at risk for complications of strictures and esophageal malignancy. We hypothesized there might be unique clinical features in patients with reflux esophagitis in a predominantly Hispanic population of a large, safety-net hospital.

AIM

Define clinical and endoscopic features of reflux esophagitis in a predominantly Hispanic population of a large, safety-net hospital.

METHODS

This is retrospective comparative study of outpatients and hospitalized patients identified with mild (Los Angeles Grade A/B) and severe (Los Angeles Grade C/D) esophagitis through an endoscopy database review. The electronic medical record was reviewed for demographic and clinical data.

RESULTS

Reflux esophagitis was identified in 382/5925 individuals: 56.5% males and 79.8% Hispanic. Multivariable logistic regression model adjusted for age, gender, race, body mass index (BMI), tobacco and alcohol use, and hospitalization status with severity as the outcome showed an interaction between gender and BMI (p ≤ 0.01). Stratification by gender showed that obese females had decreased odds of severe esophagitis compared to normal BMI females (OR = 0.18, 95% CI = 0.07-0.47; p < 0.01). In males, the odds of esophagitis were higher in inpatient status (OR = 2.84, 95% CI = 1.52 - 5.28; p < 0.01) and as age increased (OR = 1.37, 95% CI = 1.03 - 1.83; p = 0.03).

CONCLUSIONS

We identify gender-specific associations with severe esophagitis in a predominantly Hispanic cohort. In females, obese BMI appears to be protective against severe esophagitis compared to normal BMI, while in men inpatient status and increasing age were associated with increased odds of severe esophagitis.

The Esophageal Adenocarcinoma Epidemic Has Reached Hungary: A Multicenter, Cross-Sectional Study

BACKGROUND

The epidemiology of esophageal cancer has changed dramatically over the past 4 decades in many Western populations. We aimed to understand the Hungarian epidemiologic trends of esophageal squamous cell cancer (SCC) and adenocarcinoma (AC).

METHODS

We performed a cross-sectional study using data from esophageal cancer patients diagnosed between 1992 and 2018 at eight tertiary referral centers in four major cities of Hungary. We retrospectively identified cases in the electronic databases of each center and collected data on gender, age at diagnosis, year of diagnosis, specialty of the origin center, histological type, and localization of the tumor. Patients were grouped based on the two main histological types: AC or SCC. For statistical analysis, we used linear regression models, chi-square tests, and independent sample t tests.

RESULTS

We extracted data on 3,283 patients with esophageal cancer. Of these, 2,632 were diagnosed with either of the two main histological types; 737 had AC and 1,895 SCC. There was no significant difference in the gender ratio of the patients between AC and SCC (80.1 vs 81.8% males, respectively; p = 0.261). The relative incidence of AC increased over the years (p < 0.001, b = 1.19 CI: 0.84-1.54). AC patients were older at diagnosis than SCC patients (64.37 ± 11.59 vs 60.30 ± 10.07 years, p < 0.001). The age of patients at the diagnosis of primary esophageal cancer increased over time (p < 0.001, R = 0.119).

CONCLUSIONS

The rapid increase in the relative incidence of AC and simultaneous decrease of the relative incidence of SCC suggest that this well-established Western phenomenon is also present in Hungary.

Anthropometry, body fat composition and reproductive factors and risk of oesophageal and gastric cancer by subtype and subsite in the UK Biobank cohort

BACKGROUND

Obesity has been positively associated with upper gastrointestinal cancers, but prospective data by subtype/subsite are limited. Obesity influences hormonal factors, which may play a role in these cancers. We examined anthropometry, body fat and reproductive factors in relation to oesophageal and gastric cancer by subtype/subsite in the UK Biobank cohort.

METHODS

Among 458,713 UK Biobank participants, 339 oesophageal adenocarcinomas, 124 oesophageal squamous cell carcinomas, 137 gastric cardia and 92 gastric non-cardia cancers were diagnosed during a mean of 6.5 years follow-up. Cox models estimated multivariable hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Body mass index (BMI), hip circumference, waist circumference, waist-to-hip ratio, waist-to-height ratio, total body fat and trunk fat were positively associated with oesophageal adenocarcinoma (highest vs lowest category: HR = 2.33, 95%-CI:1.65-3.28; HR = 1.56, 95%-CI:1.15-2.13; HR = 2.30, 95%-CI:1.47-3.57; HR = 1.71, 95%-CI:1.01-2.90; HR = 2.87, 95%-CI:1.88-4.38; HR = 1.96, 95%-CI:1.30-2.96; HR = 2.34, 95%-CI:1.70-3.22, respectively). Although there were no statistically significant associations in combined sex analyses, BMI (HR = 1.83, 95%-CI:1.00-3.37), waist circumference (HR = 2.21, 95%-CI:1.27-3.84) and waist-to-hip ratio (HR = 1.92, 95%-CI:1.11-3.29) were associated with gastric cardia cancer in men; however, mutual adjustment attenuated the associations for BMI and waist-to-hip ratio. For oesophageal squamous cell carcinoma, statistically significant inverse associations were observed among women for BMI, hip circumference, waist circumference, waist-to-height ratio, total body fat and trunk fat, although they were based on small numbers. In addition, older age at first (HR = 0.44, 95%-CI:0.22-0.88) and last live birth (HR = 0.44, 95%-CI:0.22-0.87) were inversely associated with oesophageal squamous cell carcinoma and having a stillbirth/miscarriage/termination was positively associated (HR = 1.84, 95%-CI:1.10-3.07).

CONCLUSIONS

Obesity and abdominal obesity specifically may be a risk factor for oesophageal adenocarcinoma and gastric cardia cancer in men. Some reproductive factors may be associated with oesophageal squamous cell carcinoma in women.

Urinary exposure of N-nitrosamines and associated risk of esophageal cancer in a high incidence area in China

Esophageal cancer (EC) is a deadly malignancy worldwide with a high incidence and exhibits unevenly geographic prevalence, which suggests that environmental factors are deeply involved in the development of EC. Although the carcinogenesis of nitrosamines in the esophagus has been identified by tremendous toxicological data, the role of nitrosamines in the genesis of human EC has so far proved inconclusive largely due to a lack of convincing evidences. In this study, urinary nitrosamines in population controls and cases with esophageal precancerous lesions, including reflux esophagitis (RE) accompanying with basal cell hyperplasia (BCH) and dysplasia (DYS), and esophageal squamous cell carcinoma (ESCC) were detected by a SPE-LC-MS/MS method and the associated risk was evaluated. Higher excretion concentrations of N-nitrosomethylethylamine (NMEA) in the RE/BCH patients, NMEA and N-nitrosodibutylamine (NDBA) in the DYS patients, and NMEA, NDBA, N-nitrosopyrrolidine (NPyr) and N-nitrosomorpholine (NMor) in the ESCC patients were observed compared with the controls (p < .05). And with the progression of esophageal lesion, the exposure complexity increased in terms of the categories of nitrosamines. Furthermore, the observed positive associations between the hazardous exposure of NMEA, NDBA and NPyr and the increased risk of ESCC, and between NMEA and NDBA and RE/BCH were established. These findings provided direct evidence to support the hypothesis that exposure to nitrosamines are involved in the carcinogenesis of esophageal epithelia in this high incidence area from the perspective of endogenous exposure assessment. However, discoveries in this study need to be confirmed by systematic researches in the future. And the dose-response relationships, the reference ranges or cutoff values to predict the risks of nitrosamines exposure also need to be defined.

Circulating Levels of Inflammatory and Metabolic Biomarkers and Risk of Esophageal Adenocarcinoma and Barrett Esophagus: Systematic Review and Meta-analysis

Associations between circulating levels of obesity-related biomarkers and risk of esophageal adenocarcinoma and Barrett esophagus have been reported, but the results are inconsistent. A literature search until October 2018 in MEDLINE and EMBASE was performed. Pooled ORs with 95% confidence intervals (CI) were estimated for associations between 13 obesity-related inflammatory and metabolic biomarkers and risk of esophageal adenocarcinoma or Barrett esophagus using random effect meta-analyses. Among 7,641 studies, 19 were eligible for inclusion (12 cross-sectional, two nested case-control, and five cohort studies). Comparing the highest versus lowest categories of circulating biomarker levels, the pooled ORs were increased for leptin (OR, 1.68; 95% CI, 0.95-2.97 for Barrett esophagus), glucose (OR, 1.12; 95% CI, 1.03-1.22 for esophageal adenocarcinoma), insulin (OR, 1.47; 95% CI, 1.06-2.00 for Barrett esophagus), C-reactive protein (CRP; OR, 2.06; 95% CI, 1.28-3.31 for esophageal adenocarcinoma), IL6 (OR, 1.50; 95% CI, 1.03-2.19 for esophageal adenocarcinoma), and soluble TNF receptor 2 (sTNFR-2; OR, 3.16; 95% CI, 1.76-5.65 for esophageal adenocarcinoma). No associations were identified for adiponectin, ghrelin, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, triglycerides, IL8, or TNFα. Higher circulating levels of leptin, glucose, insulin, CRP, IL6, and sTNFR-2 may be associated with an increased risk of esophageal adenocarcinoma or Barrett esophagus. More prospective studies are required to identify biomarkers that can help select high-risk individuals for targeted prevention and early detection.

Prevalence of reflux esophagitis in obese Japanese undergoing bariatric surgery

Background

Currently, the data on the relationship between obesity and gastroesophageal reflux disease (GERD) in Asian populations are scarce.

Methods

The aim of this study is to investigate the prevalence of reflux esophagitis (RE) among obese Japanese patients in each body mass index (BMI) range group. In addition, we aim to investigate the risk factors for RE in obese Japanese patients. The present retrospective cohort study included 674 obese Japanese patients who underwent bariatric surgery between January 2003 and April 2016. The patients were stratified into five groups based on BMI range.

Results

The mean BMI was 42.7 ± 9.24 kg/m². The prevalence of RE among each of the groups was as follows: Group 1 (BMI 30–34.9) = 20.7%; Group 2 (BMI 35–39.9) = 24.0%; Group 3 (BMI 40–44.9) = 25.2%; Group 4 (BMI 45–49.9) = 26.7%; and Group 5 (BMI ≥50) = 24.8%. Overall, the prevalence of RE was 24.2% in our study. Furthermore, no significant difference in BMI was noted between the RE and non‐RE groups (43.4 ± 9.3 kg/m² and 42.5 ± 10.2 kg/m², respectively; p = 0.24). According to the multivariate logistic regression model, gender, Helicobacter pylori infection status, GERD‐related symptoms, and hiatal hernia were significantly correlated with RE.

Conclusion

Our study shows that the prevalence of RE in severely obese Japanese patients was significantly higher than the average prevalence of RE in Japan. However, the prevalence of RE did not increase with BMI in our cohort.

Obesity and esophageal cancer: GERD, Barrett´s esophagus, and molecular carcinogenic pathways

INTRODUCTION

Increases in the rates of esophageal adenocarcinoma (EAC) have paralleled rises in the prevalence of overweight and obesity. Despite not being fully understood, obesity-related EAC seems to have different carcinogenic pathways.

AREAS COVERED

This comprehensive review will thoroughly evaluate the current literature, describing the underlying mechanisms that help understanding the strong association between obesity and esophageal cancer.

EXPERT COMMENTARY

The risk of esophageal cancer among obese individuals could be partially explained by several factors: high prevalence of GERD; linear association between central adiposity and Barrett´s esophagus development; low levels of adiponectin and high levels of leptin that alter cell proliferation processes; insulin-resistant state that creates a tumorigenesis environment; and changes in the esophageal microbiota due to unhealthy dietary habits that promote carcinogenesis. In addition, a large proportion of obese patients are undergoing sleeve gastrectomy which can worsen GERD or cause de novo reflux, esophagitis, and Barrett´s metaplasia.

[Impact of Sarcopenia on the Risk of Erosive Esophagitis]

Background/Aims

An association between obesity and erosive esophagitis has been reported, but the effects of sarcopenia and obesity on erosive esophagitis are unknown. This study examined the relationship between obesity, sarcopenia, sarcopenic obesity, and erosive esophagitis in a large population of asymptomatic men and women.

Methods

This study analyzed 32,762 subjects who underwent a comprehensive health check-up, which included upper gastrointestinal endoscopy, from August 2006 to December 2011 by a cross-sectional study. Sarcopenia was defined as a decrease in the appendicular skeletal muscle mass (ASM)/body weight value of two SD or more below the normal means for a younger reference group.

Results

The study was carried out on four groups according to obesity and sarcopenic status: normal, obesity, sarcopenic, and sarcopenic obese group. In a multivariable model, the risk of erosive esophagitis was higher in the obese (adjusted OR [aOR] 1.35, 95% CI 1.22-1.49), sarcopenic (aOR 2.12, 95% CI 1.40-3.19), and sarcopenic obese groups (aOR 1.54, 95% CI 1.27-1.87) than in the normal group. The risk of erosive esophagitis was higher in the sarcopenic and sarcopenic obese groups than the obese group; the ORs were 1.63 (95% CI 1.08-2.47) and 1.22 (95% CI 1.01-1.46), respectively. In dose-response analysis, increasing sarcopenia severity showed a positive and graded relationship with the overall, Los Angeles (LA)-B or higher grade, and LA-C erosive esophagitis.

Conclusions

This study suggests that sarcopenia is strongly and progressively associated with erosive esophagitis.

Anthropometric and reproductive factors and risk of esophageal and gastric cancer by subtype and subsite: Results from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5-25 kg/m2 : HR = 1.94, 95% CI: 1.25-3.03) and women (HR = 2.66, 95% CI: 1.15-6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99-6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52-4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35-14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76-18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14-0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32-0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04-3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers.

Adverse effects of being underweight on young female breast cancer patients with lymph node metastases

Background: This study aimed to examine the effect of underweight in breast cancer.

Methods: We performed a retrospective analysis of 3891 female patients diagnosed with primary breast cancer (I-IV stages). Body mass index (BMI) defined by World Health Organization criteria as follow: Underweight (UW; BMI<18.5 kg/m²), normal weight (NW; BMI =18.5-24.9 kg/m²) and overweight or obese (OW; BMI≥25 kg/m²). We performed to evaluate the association between low BMI and clinical outcome in different age (18-40 years and over 40 years) breast cancer.

Results: In our study, about 7% patients suffer from being underweight and 25% patients suffer from being overweight. Underweight is more prominent in young age group. Although no relationship was found between the recurrence rate and being underweight (HR 1.467(95 % CI 0.940-2.291), P=0.092 for disease-free survival), multivariate regression analysis confirmed that low BMI was an independent overall survival (OS) prognostic factor in young patients (HR 1.610(95 % CI 1.028-2.523), P=0.037 for OS). Further analysis showed the prognostic significance of underweight only seen in young patients with axillary lymph node metastasis or III-IV stage patients.

Conclusions: Our results demonstrate the prognostic importance of low BMI in young breast cancer patients (under 40 years old) with lymph node metastases. The role of low BMI in breast cancer might depend on patients' age and clinical stage.

Association Between Metformin Use and Risk of Esophageal Squamous Cell Carcinoma in a Population-Based Cohort Study

OBJECTIVES

Esophageal cancer is a highly fatal malignant neoplasm, with 2 etiologically different histological types. A large prospective study is expected to elucidate the specific risk of the 90% subtype of esophageal cancer, esophageal squamous cell carcinoma (ESCC), with metformin therapy. This study aims to determine the association between metformin use and incident ESCC risk.

METHODS

This was a nationwide population-based prospective cohort study conducted in Sweden in 2005-2015. Among 8.4 million participants identified in the cohort, 411,603 (5%) were metformin users. The users were compared with 10 times as many frequency-matched nonusers of metformin (n = 4,116,030) by age and sex. Metformin use was treated as a time-varying variate, and multivariable cause-specific proportional hazards model was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for ESCC, adjusted for age, sex, calendar year, residence area, tobacco smoking, alcohol overconsumption, and use of nonsteroidal anti-inflammatory drugs or statins.

RESULTS

The incidence rates of ESCC were 3.5 per 100,000 person-years among the metformin users and 5.3 per 100,000 person-years in the nonusers. Metformin users overall were at a decreased risk of ESCC compared with nonusers (HR 0.68, 95% CI 0.54-0.85). The decrease in risk was more pronounced in new metformin users (HR 0.44, 95% CI 0.28-0.64) and participants aged 60-69 years (HR 0.45, 95% CI 0.31-0.66).

DISCUSSION

Metformin use decreases the risk of developing ESCC.

Shared Genetic Etiology of Obesity-Related Traits and Barrett's Esophagus/Adenocarcinoma: Insights from Genome-Wide Association Studies

BACKGROUND

Obesity is a major risk factor for esophageal adenocarcinoma (EA) and its precursor Barrett's esophagus (BE). Research suggests that individuals with high genetic risk to obesity have a higher BE/EA risk. To facilitate understanding of biological factors that lead to progression from BE to EA, the present study investigated the shared genetic background of BE/EA and obesity-related traits.

METHODS

Cross-trait linkage disequilibrium score regression was applied to summary statistics from genome-wide association meta-analyses on BE/EA and on obesity traits. Body mass index (BMI) was used as a proxy for general obesity, and waist-to-hip ratio (WHR) for abdominal obesity. For single marker analyses, all genome-wide significant risk alleles for BMI and WHR were compared with summary statistics of the BE/EA meta-analyses.

RESULTS

Sex-combined analyses revealed a significant genetic correlation between BMI and BE/EA (r_g = 0.13, P = 2 × 10^-04) and a r_g of 0.12 between WHR and BE/EA (P = 1 × 10^-02). Sex-specific analyses revealed a pronounced genetic correlation between BMI and EA in females (r_g = 0.17, P = 1.2 × 10^-03), and WHR and EA in males (r_g = 0.18, P = 1.51 × 10^-02). On the single marker level, significant enrichment of concordant effects was observed for BMI and BE/EA risk variants (P = 8.45 × 10^-03) and WHR and BE/EA risk variants (P = 2 × 10^-02).

CONCLUSIONS

Our study provides evidence for sex-specific genetic correlations that might reflect specific biological mecha-nisms. The data demonstrate that shared genetic factors are particularly relevant in progression from BE to EA.

IMPACT

Our study quantifies the genetic correlation between BE/EA and obesity. Further research is now warranted to elucidate these effects and to understand the shared pathophysiology.

Association between Lifestyle and Gastroesophageal Reflux Disease Questionnaire Scores: A Cross-Sectional Study of 37 442 Chinese Adults

The aim of this study was to investigate the distribution characteristics of GerdQ results in a Chinese population and the association between lifestyle and GerdQ scores. Among the 37 442 individuals enrolled from September 2009 to March 2016, 7 449 (19.89%) had a GerdQ score of ≥8 points and 29 993 (80.11%) had a GerdQ score of <8 points. The percentage of men with suspected GERD was significantly higher than the percentage of women with suspected GERD (χ 2 = 111.571, P ≤ 0.001), and the prevalence of GERD was higher in the young and middle-aged populations than in the elderly population. The prevalence of GERD increased gradually with weight gain (χ 2 = 145.227, P ≤ 0.001). With regard to lifestyle, the prevalence of GERD in the subjects who smoked (χ 2 = 119.361, P ≤ 0.001), consumed alcohol excessively, lacked physical activity (χ 2 = 86.916, P ≤ 0.001), and had an excessive intake of oil, meat, fish, and eggs showed an ascending trend (χ 2 = 105.388, P ≤ 0.001). In contrast, an adequate intake of vegetables (≥300 g/d) and fruit (≥200 g/d) was associated with a significantly lower incidence of GERD. Suspected GERD is very common in individuals undergoing health examinations. Unhealthy lifestyles are closely related to the high incidence of suspected GERD. GerdQ scores can play a role in screening for GERD.

Evaluation and Management of Premalignant Conditions of the Esophagus: A Systematic Survey of International Guidelines

Esophageal cancer represents one of the most lethal forms of malignancy. The growing incidence of esophageal adenocarcinoma represents an emerging public health concern. This review article summarizes current diagnostic, management, and therapeutic practices of premalignant conditions of the esophagus including Barrett's esophagus, tylosis, granular cell tumors, achalasia, and the ingestion of caustic substances. Our report provides clinicians and academics with a global clinical perspective regarding presentation, surveillance guidelines, and therapeutic management of these esophageal conditions.

Metabolically Healthy Obesity and the Risk of Erosive Esophagitis: A Cohort Study

OBJECTIVES

Obesity is an established risk factor of erosive esophagitis, and metabolic unhealthiness has been implicated in the pathogenesis of erosive esophagitis. Yet, the risk of erosive esophagitis among obese individuals without obesity-related metabolic unhealthiness, a condition referred to as "metabolically healthy obese (MHO)", remains unclear. We examined the association between body mass index (BMI) categories and the development of erosive esophagitis in a cohort of metabolically healthy individuals.

METHODS

We conducted a cohort study of 14,725 asymptomatic adults free of erosive esophagitis and metabolic abnormalities, who underwent repeated health checkups including screening endoscopy. A metabolically healthy state was defined as having no metabolic syndrome components and a homeostasis model assessment of insulin resistance <2.5. The presence of erosive esophagitis was determined using endoscopy.

RESULTS

During 81,385.2 person-years of follow-up, 1,865 participants developed erosive esophagitis (incidence rate, 22.9 per 1,000 person-years). The multivariable adjusted hazard ratios (95% confidence intervals) for incident erosive esophagitis comparing overweight (BMI 23.0-24.9) and obese (≥25) with normal-weight participants (18.5-22.9) were 1.12 (1.00-1.25) and 1.29 (1.14-1.47), respectively. In dose-response analyses, increasing BMI also showed positive association with overall and LA-B grade or higher. The association persisted in MHO individuals without central obesity. The association between waist circumference categories and the development of erosive esophagitis was also evident.

DISCUSSION

In a large cohort of strictly defined metabolically healthy men and women, the MHO phenotype was associated with an increased incidence of erosive esophagitis, providing evidence that the MHO phenotype is not protective from gastroesophageal reflux disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Alteration of the esophageal microbiota in Barrett's esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in recent decades, and its 5-year survival rate is less than 20%. As a well-established precursor, patients with Barrett's esophagus (BE) have a persistent risk of progression to EAC. Many researchers have already identified some factors that may contribute to the development of BE and EAC, and the identified risks include gastroesophageal reflux (GER), male sex, older age, central obesity, tobacco smoking, Helicobacter pylori (H. pylori) eradication, and the administration of proton pump inhibitors (PPIs) and antibiotics. The human gut harbors trillions of microorganisms, the majority of which are bacteria. These microorganisms benefit the human host in many ways, such as helping in digestion, assisting in the synthesis of certain vitamins, promoting the development of the gastrointestinal immune system, regulating metabolism and preventing invasion by specific pathogens. In contrast, microbial dysbiosis may play important roles in various diseases, such as inflammation and cancers. The composition of the microbiota located in the normal esophagus is relatively conserved without distinct microbial preferences in the upper, middle and lower esophagus. Six major phyla constitute the esophageal microbiota, including Firmicutes, Bacteroides, Actinobacteria, Proteobacteria, Fusobacteria and TM7, similar to the oral microbiota. Streptococcus dominates the esophageal microbiota. However, the microbiota varies in different esophageal diseases compared to that in the healthy esophagus. The type I microbiota, which is primarily composed of gram-positive bacteria, is closely associated with the normal esophagus, while type II microbiota has enriched gram-negative bacteria and is mainly associated with the abnormal esophagus. These increased gram-negative anaerobes/microaerophiles include Veillonella, Prevotella, Haemophilus, Neisseria, Granulicatella and Fusobacterium, many of which are associated with BE. The microbial diversity in the esophagus is decreased in EAC patients, and Lactobacillus fermentum is enriched compared to that in controls and BE patients. Furthermore, the microbiota may be associated with BE and EAC by interacting with their risk factors, including central obesity, GER, H. pylori, administration of PPIs and antibiotics. Therefore, a large gap in research must be bridged to elucidate the associations among these factors. Some studies have already proposed several potential mechanisms by which the microbiota participates in human carcinogenesis by complicated interactions with the human host immune system and signaling pathways. The activation of the LPS-TLR4-NF-κB pathway may contribute to inflammation and malignant transformation. This exciting field of gastrointestinal microbiota allows us to unravel the mystery of carcinogenesis from another perspective. Further studies are needed to explore whether the microbiota changes before or after disease onset, to improve our understanding of the pathogenesis, and to find novel targets for prevention, diagnosis and therapy, which could offer more cost-effective and relatively safe choices.

Prognostic significance of combined pretreatment body mass index (BMI) and BMI loss in patients with esophageal cancer

Background: Body mass index (BMI) has been associated with a risk of esophageal cancer. However, the influence of BMI and BMI loss on people with esophageal cancer that were treated with different therapies has not been described in China.

Methods: In total, 615 consecutive patients that underwent esophagectomy and/or chemotherapy/radiotherapy were classified according to the Asian-specific BMI (kg/m²) cutoff values. The impact of BMI and BMI loss on long-term overall survival (OS) was estimated using the Kaplan–Meier method and Cox proportional hazard models.

Results: Multivariate analysis showed that overweight and obese patients had a more favorable survival than normal weight and underweight patients (p=0.017). Patients with a low BMI and high BMI loss before therapy had worse OS than others (p=0.001). Subgroup analysis showed that patients with a high BMI were more likely to suffer hypertension (p<0.001) and receive only surgery (p<0.001), and they were less likely to be smokers (p=0.007) and anemic (p<0.001). Conversely, patients with high BMI loss were more likely to be anemic (p=0.001), to have advanced pathological stage (p=0.012), and to receive chemotherapy and radiotherapy (p=0.001). Moreover, the mortality rate was higher when patients had a high BMI loss. There is no survival benefit of higher BMI in the non-esophageal squamous cell carcinoma (ESCC) group.

Conclusion: Pretreatment BMI was an independent prognostic factor for long-term survival in esophageal cancer patients treated with different treatments. The overall survival was increased in esophageal cancer patients with a high pretreatment BMI and no BMI loss. There is no survival benefit of higher BMI in the non-ESCC group.

Relationship Between Meal Frequency and Gastroesophageal Reflux Disease (GERD) in Iranian Adults

BACKGROUND

The association between frequency of meals and snacks and gastroesophageal reflux disease (GERD) is less studied in Middle-Eastern countries.

AIM

We aimed to determine the relationship between meal and snack frequency with GERD symptoms in a large sample of Iranian adults.

METHODS

In this cross-sectional study, 4669 individuals filled out a questionnaire about their number of meals and snacks. Frequency of total meals was defined by summing up the frequency of main meals and snacks, and participants were categorized into four categories: < 3, 3-5, 6-7 and ≥ 8 meals/day. GERD was defined as having heartburn sometimes or more during the last 3 months. The severity of disease was assessed.

RESULTS

The prevalence of GERD in the study population was 23.7%. There was no significant association between meal or snack frequency and GERD symptoms in the whole population. However, after adjustment of all potential confounders, we found that women who consumed 1-2 or 3-5 snacks per day, compared with those who never had snacks, had a 41% (OR 0.59; 95% CI 0.42-0.84) and 51% (OR 0.49; 95% CI 0.32-0.75) reduced risk of having GERD, respectively. Women who consumed 6-7 or ≥ 8 snacks and meals per day had a 38% (OR 0.62; 95% CI 0.41-0.96) and 43% (OR 0.57; 95% CI 0.34-0.95) risk reduction for GERD compared with those who ate < 3 snacks and meals per day.

CONCLUSION

We found no significant association between meal frequency and GERD symptoms in the whole population. Gender-specific analysis revealed inverse associations between meal and snack frequency and GERD in Iranian women. Further prospective studies are required to confirm these associations.

ESCC ATLAS: A population wide compendium of biomarkers for Esophageal Squamous Cell Carcinoma

Esophageal cancer (EC) is the eighth most aggressive malignancy and its treatment remains a challenge due to the lack of biomarkers that can facilitate early detection. EC is identified in two major histological forms namely - Adenocarcinoma (EAC) and Squamous cell carcinoma (ESCC), each showing differences in the incidence among populations that are geographically separated. Hence the detection of potential drug target and biomarkers demands a population-centric understanding of the molecular and cellular mechanisms of EC. To provide an adequate impetus to the biomarker discovery for ESCC, which is the most prevalent esophageal cancer worldwide, here we have developed ESCC ATLAS, a manually curated database that integrates genetic, epigenetic, transcriptomic, and proteomic ESCC-related genes from the published literature. It consists of 3475 genes associated to molecular signatures such as, altered transcription (2600), altered translation (560), contain copy number variation/structural variations (233), SNPs (102), altered DNA methylation (82), Histone modifications (16) and miRNA based regulation (261). We provide a user-friendly web interface ( http://www.esccatlas.org , freely accessible for academic, non-profit users) that facilitates the exploration and the analysis of genes among different populations. We anticipate it to be a valuable resource for the population specific investigation and biomarker discovery for ESCC.

ESCC ATLAS: A population wide compendium of biomarkers for Esophageal Squamous Cell Carcinoma

Esophageal cancer (EC) is the eighth most aggressive malignancy and its treatment remains a challenge due to the lack of biomarkers that can facilitate early detection. EC is identified in two major histological forms namely - Adenocarcinoma (EAC) and Squamous cell carcinoma (ESCC), each showing differences in the incidence among populations that are geographically separated. Hence the detection of potential drug target and biomarkers demands a population-centric understanding of the molecular and cellular mechanisms of EC. To provide an adequate impetus to the biomarker discovery for ESCC, which is the most prevalent esophageal cancer worldwide, here we have developed ESCC ATLAS, a manually curated database that integrates genetic, epigenetic, transcriptomic, and proteomic ESCC-related genes from the published literature. It consists of 3475 genes associated to molecular signatures such as, altered transcription (2600), altered translation (560), contain copy number variation/structural variations (233), SNPs (102), altered DNA methylation (82), Histone modifications (16) and miRNA based regulation (261). We provide a user-friendly web interface ( http://www.esccatlas.org , freely accessible for academic, non-profit users) that facilitates the exploration and the analysis of genes among different populations. We anticipate it to be a valuable resource for the population specific investigation and biomarker discovery for ESCC.