Familial aggregation of gastroesophageal reflux in patients with Barrett's esophagus and esophageal adenocarcinoma

Systematic review with meta-analysis: the effects of family history on the risk of Barrett's oesophagus and oesophageal adenocarcinoma

BACKGROUND

Current guidelines recommend different screening approaches for individuals with a family history of Barrett's oesophagus (BO) or oesophageal adenocarcinoma (OAC), varying from no screening to screening all individuals with a positive family history.

AIMS

To determine evidence-based risk estimates for individuals with a family history of BO or OAC METHODS: We systematically searched Pubmed, Embase and Cochrane Library until October 2020 to identify all studies that reported on the association between family history and the risk of BO and OAC. Pooled summary estimates of adjusted relative risks and prevalence of familial BO/OAC with 95% confidence intervals (CIs) were calculated using a random effects model.

RESULTS

Fourteen studies comprising 16 189 BO/OAC patients were analysed. Familial clustering was seen in 8.84% (95% CI: 5.54-13.82) and 4.37% (95% CI: 2.15-8.69) of patients with BO and OAC, respectively (nine studies). Screening first-degree relatives of BO patients had a diagnostic yield between 12% and 44% for BO (four studies). However, the yield for high-grade dysplasia and OAC was low (<2%). Individuals with a positive family history had a higher risk of having BO (aRR 3.26; 95% CI 1.43-7.40; I²  = 46%; three studies) and OAC (aRR 2.19; 95% CI 1.14-4.21; I²  = 48%; five studies) compared to individuals without a family history.

CONCLUSIONS

A verified family history of BO or OAC is a strong risk factor for both BO and OAC. A positive family history could be a clinically meaningful way to identify high-risk individuals who may benefit from early detection strategies.

Current advances in the treatment of gastroesophageal reflux disease: a focus on esophageal protection

Gastroesophageal reflux disease (GERD) is characterized by high morbidity and a significant decrease in the quality of life of patients, and is a major risk factor for esophageal adenocarcinoma. Nowadays, antisecretory therapy with proton pump inhibitors (PPI) is the "gold standard" of conservative treatment of GERD, but in some cases this therapy is unsuccessful. According to various studies, the prevalence of refractory GERD can reach 30-40%. The latest scientific data in the field of genetics and pathophysiology of GERD demonstrate that a disruption of the barrier function of the esophageal mucosa and an increase of its permeability can be the leading causes of refractoriness. Thus, the optimal therapy for patients with GERD should not only suppress the secretion of hydrochloric acid, but also restore the barrier function of the mucous membrane, providing an esophagoprotective effect. To achieve these goals, Alfasoxx was developed, which consists of a mixture of low molecular weight hyaluronic acid and low molecular weight chondroitin sulfate dissolved in a bioadhesive carrier (poloxamer 407). The clinical efficacy of this product has been confirmed by three prospective, randomized, placebo - controlled trials. Alfasoxx has a healing and restorative effect towards the esophageal epithelium and due to high ability for bioadhesion provides long - term protection of the mucous membrane of the esophagus. Combination therapy for GERD with the use of PPI and an esophagoprotector offers new perspectives for the treatment of patients with GERD.

Esophageal adenocarcinoma in a first-degree relative increases risk for esophageal adenocarcinoma in patients with Barrett's esophagus

Background

The significance of a family history of esophageal adenocarcinoma in the progression to esophageal adenocarcinoma in patients with Barrett's esophagus has not been thoroughly evaluated. The purpose of this study is to evaluate the presence of esophageal adenocarcinoma in a first-degree relative in patients with Barrett's esophagus.

Methods

A retrospective cohort study was conducted of patients with Barrett's esophagus at a tertiary care center undergoing radiofrequency ablation. Family history, demographics, and pathology and endoscopy reports were assessed in all patients.

Findings

Three hundred and one patients with Barrett's esophagus were assessed. Nineteen patients who had a diagnosis of esophageal adenocarcinoma on index endoscopy were excluded. Nineteen (6.7%) patients had a first-degree relative with esophageal adenocarcinoma. Four (21.1%) of these patients progressed to esophageal adenocarcinoma. Of patients without first-degree relative with esophageal adenocarcinoma 22/263 (8.7%) progressed to esophageal adenocarcinoma. In a logistic regression model adjusted for sex and the number of radiofrequency ablation treatments, we found that family history of esophageal adenocarcinoma was a significant independent predictor of progression to esophageal adenocarcinoma (odds ratio = 5.55, 95% confidence interval: 1.47-20.0).

Conclusion

Our study indicates that Barrett's esophagus patients with a first-degree family member with esophageal adenocarcinoma are at 5.5-fold higher risk for disease progression to esophageal adenocarcinoma. Family history of esophageal adenocarcinoma in Barrett's esophagus patients should be considered in patient surveillance and radiofrequency ablation treatment, beyond recommended guidelines.

The Evolving Genomic Landscape of Barrett's Esophagus and Esophageal Adenocarcinoma

We have recently gained unprecedented insight into genetic factors that determine risk for Barrett's esophagus (BE) and progression to esophageal adenocarcinoma (EA). Next-generation sequencing technologies have allowed us to identify somatic mutations that initiate BE and track genetic changes during development of tumors and invasive cancer. These technologies led to identification of mechanisms of tumorigenesis that challenge the current multistep model of progression to EA. Newer, cost-effective technologies create opportunities to rapidly translate the analysis of DNA into tools that can identify patients with BE at high risk for cancer, detect dysplastic lesions more reliably, and uncover mechanisms of carcinogenesis.

A meta-analysis of reflux genome-wide association studies in 6750 Northern Europeans from the general population

BACKGROUND

Gastroesophageal reflux disease (GERD), the regurgitation of gastric acids often accompanied by heartburn, affects up to 20% of the general population. Genetic predisposition is suspected from twin and family studies but gene-hunting efforts have so far been scarce and no conclusive genome-wide study has been reported. We exploited data available from general population samples, and studied self-reported reflux symptoms in relation to genome-wide single nucleotide polymorphism (SNP) genotypes.

METHODS

We performed a GWAS meta-analysis of three independent population-based cohorts from Sweden, Finland, and UK. GERD cases (n=2247) and asymptomatic controls (n=4503) were identified using questionnaire-derived symptom data. Upon stringent quality controls, genotype data for more than 2.5M markers were used for association testing. Bioinformatic characterization of genomic regions associated with GERD included gene-set enrichment analysis (GSEA), in silico prediction of genetic risk effects on gene expression, and computational analysis of drug-induced gene expression signatures using Connectivity Map (cMap).

KEY RESULTS

We identified 30 GERD suggestive risk loci (P≤5×10^-5 ), with concordant risk effects in all cohorts, and predicted functional effects on gene expression in relevant tissues. GSEA revealed involvement of GERD risk genes in biological processes associated with the regulation of ion channel and cell adhesion. From cMap analysis, omeprazole had significant effects on GERD risk gene expression, while antituberculosis and anti-inflammatory drugs scored highest among the repurposed compounds.

CONCLUSIONS

We report a large-scale genetic study of GERD, and highlight genes and pathways that contribute to further our understanding of its pathogenesis and therapeutic opportunities.

Human leukocyte antigen HLADRB1 determinants susceptibility to gastroesophageal reflux disease

BACKGROUND

- Gastroesophageal reflux disease (GERD) is characterized by diverse symptoms. There is an evidence for a genetic component to GERD as supported by familial aggregation of this disease.

OBJECTIVE

- To investigate whether certain human leucocyte antigen genes HLA-DRB1 are associated with GERD.

METHODS

- Patients and controls were prospectively recruited from GIT center at Al-Kindy Teaching Hospital (Baghdad-Iraq) between January 2014 and July 2016. Sixty Iraqi Arab Muslims patients with a history of heartburn and dyspepsia compared with 100 Iraqi Arab Muslims controls. All study patients and control groups underwent upper gastrointestinal endoscopic examinations and their serums were analyzed for CagA antibodies Immunoglobulin G (IgG) for H. pylori. HLA-DRB1 genotyping were done to both groups.

RESULTS

- A total of 60 patients with erosive gastritis; GERD (Grade II and III) were evaluated, together with 100 controls. There is a significant increase of H. pylori infection (P=0.0001) in GERD patients than control group. HLA-DRB1* 15:01 was significantly increased in GERD patients in comparison with control group and an increased frequency of HLADRB1*11:01 in control group compared with patients group.

CONCLUSION

- There is an association between HLA-DRB1 *15:01 in GERD patients with H. pylori positive patients.

Duodenal Contents Reflux-Induced Laryngitis in Rats: Possible Mechanism of Enhancement of the Causative Factors in Laryngeal Carcinogenesis

Objectives:

The main factors considered responsible for the onset of laryngeal cancer are tobacco smoking and alcohol abuse. Recently, gastroesophageal reflux has also been implicated as a causative factor in several laryngeal disorders, including laryngeal cancer. However, the significance of gastroesophageal reflux in laryngeal cancer is controversial.

Methods:

We investigated the histologic features of the esophagus and larynx in a rat model of reflux of the duodenal contents. Cell proliferation was also evaluated in laryngeal samples by detection of Ki67 antigen.

Results:

In this reflux model, laryngitis with infiltration of inflammatory cells and proliferation of small mucous glands was evident from 10 weeks after operation, and basal cell hyperplasia around the epiglottis and hyperplastic changes in the larynx were detected at 30 weeks. No dysplastic or malignant lesions were detected in the laryngeal samples within the duration of the experiment, in spite of detection of malignancy in 31.3% of lesions in esophageal samples at 30 weeks. The Ki67 index at each week was significantly higher than that of the control animals.

Conclusions:

Previous studies have shown smoking and alcohol abuse to have refluxogenic effects. Reflux of duodenal contents causes laryngitis. Reflux does not appear to be an independent risk factor for laryngeal carcinogenesis, but it may enhance the acknowledged etiologic risk factors, namely, smoking and alcohol abuse, by promoting cell proliferation.

Chronic gastroesophageal reflux disease shares genetic background with esophageal adenocarcinoma and Barrett's esophagus

Esophageal adenocarcinoma (EA) is a rapidly fatal cancer with rising incidence in the developed world. Most EAs arise in a metaplastic epithelium, Barrett's esophagus (BE), which is associated with greatly increased risk of EA. One of the key risk factors for both BE and EA is chronic gastroesophageal reflux disease (GERD). This study used the linkage disequilibrium (LD) score regression and genomic profile risk scoring approaches to investigate the contribution of multiple common single-nucleotide polymorphisms (SNPs) to the risk of GERD, and the extent of genetic overlap between GERD and BE or EA. Using LD score regression, we estimated an overall phenotypic variance of 7% (95% CI 3–11%) for GERD explained by all the genotyped SNPs. A genetic correlation of 77% (s.e. = 24%, P = 0.0012) between GERD and BE and 88% between GERD and EA (s.e. = 25%, P = 0.0004) was estimated using the LD score regression approach. Results from the genomic profile risk scoring approach, as a robustness check, were broadly similar to those from the LD score regression. This study provides the first evidence for a polygenic basis for GERD and supports for a polygenic overlap between GERD and BE, and GERD and EA.

Polymorphisms in genes in the androgen pathway and risk of Barrett's esophagus and esophageal adenocarcinoma

The strong male predominance in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remains inadequately explained, but sex hormones might be involved. We hypothesized that single nucleotide polymorphisms (SNPs) in the androgen pathway influence risk of developing BE and EAC. This genetic-epidemiological analysis included 14 studies from Australia, Europe and North America. Polymorphisms in 16 genes coding for the androgen pathway were analyzed using a gene-based approach: versatile gene-based test association study. This method evaluates associations between a trait and all SNPs within a specific gene rather than each SNP marker individually as in a conventional GWAS. The data were stratified for sex, body-mass index, waist-to-hip ratio, tobacco smoking and gastroesophageal reflux status. Included were data from 1,508 EAC patients, 2,383 BE patients and 2,170 control participants. SNPs within the gene CYP17A1 were associated with risk of BE in the sexes combined (p = 0.002) and in males (p = 0.003), but not in females separately (p = 0.3). This association was found in tobacco smokers (p = 0.003) and in BE patients without reflux (p = 0.004), but not in nonsmokers (p = 0.2) or those with reflux (p = 0.036). SNPs within JMJD1C were associated with risk of EAC in females (p = 0.001). However, none of these associations replicated in a subsequent sample. Fourteen other genes studied did not reach statistically significant levels of association with BE, EAC or the combination of BE and EAC, after correcting for the number of genes included in the analysis. In conclusion, genetic variants in the androgen-related genes CYP17A1 and JMJD1C might be associated with risk of BE and EAC, respectively, but replication data with larger sample sizes are needed.

Genetic Insights in Barrett's Esophagus and Esophageal Adenocarcinoma

Beginning in the 1980s, an alarming rise in the incidence of esophageal adenocarcinoma (EA) led to screening of patients with reflux to detect Barrett's esophagus (BE) and surveillance of BE to detect early EA. This strategy, based on linear progression disease models, resulted in selective detection of BE that does not progress to EA over a lifetime (overdiagnosis) and missed BE that rapidly progresses to EA (underdiagnosis). Here we review the historical thought processes that resulted in this undesired outcome and the transformation in our understanding of genetic and evolutionary principles governing neoplastic progression that has come from application of modern genomic technologies to cancers and their precursors. This new synthesis provides improved strategies for prevention and early detection of EA by addressing the environmental and mutational processes that can determine "windows of opportunity" in time to detect rapidly progressing BE and distinguish it from slowly or nonprogressing BE.

Smoking status and prevalence of upper gastrointestinal disorders

BACKGROUND

Lifestyle and environmental factors affecting upper gastrointestinal (GI) disorders are different in developing countries than those in developed nations.

OBJECTIVE

This study aimed to examine the association between smoking status and upper GI disorders among a large group of the Iranian adult population.

METHODS

This cross-sectional study was conducted among 1,933 adult men in Isfahan, Iran. Smoking status was assessed by a self-administered questionnaire. Required information on GI health was collected through the use of the validated ROME III questionnaire. Individuals who reported having heartburn sometimes, often, or always in the last 3 months were considered as having epidemiologic gastroesophageal reflux disease (GERD), and those who reported having heartburn often or always were considered as having clinical GERD. Subjects who reported having functional dyspepsia (FD) symptoms (based on the ROME III criteria) sometimes, often, or always in the last 3 months were considered as having epidemiologic FD, and those who reported having these disorders often or always were considered as having clinical FD.

RESULTS

Smoking was prevalent among 7.8% of the study population. FD and GERD was prevalent among 12.6% (n = 244) and 22.3% (n = 432), respectively. Smoking was not associated with GERD by either the epidemiologic or clinical definition. Although the association between smoking and FD (epidemiologic definition) was not statistically significant, smokers had an 83% higher risk of suffering from clinical FD compared with nonsmokers after taking potential confounders into account [odds ratio (OR) = 1.83, 95% CI: 1.12-3.00; p = 0.01]. Smokers had a 57% higher risk for epidemiologic postprandial fullness (OR = 1.57, 95% CI: 1.05-2.33; p = 0.02) and a 92% higher risk for clinical epigastric pain compared with nonsmokers (OR = 1.92, 95% CI: 1.02-3.62; p = 0.04). We found no significant association between smoking and severity of upper GI disorders.

CONCLUSION

This large population-based study indicated that smoking was not associated with GERD and epidemiologic FD. However, smoking was significantly associated with clinical FD, postprandial fullness, and epigastric pain.

Personal and family history of cancer and the risk of Barrett's esophagus in men

The association between Barrett's esophagus (BE) and a personal or family history of cancer other than gastroesophageal remains unknown. To evaluate the effect of personal and family history of certain cancers and cancer treatments on the risk of BE, we analyzed data from a Veterans Affairs case-control study that included 264 men with definitive BE (cases) and 1486 men without BE (controls). Patients with history of esophageal or gastric cancer were excluded. Patients underwent elective esophagogastroduodenoscopy or a study esophagogastroduodenoscopy concurrently with screening colonoscopy to determine BE status. Personal and family history of several types of cancer was obtained from self-reported questionnaires, supplemented and verified by electronic medical-record reviews. We estimated the association between personal and family history of cancer or radiation/chemotherapy, and BE. Personal history of oropharyngeal cancer (1.5% vs. 0.4%) or prostate cancer (7.2% vs. 4.4%) was more frequently present in cases than controls. The association between BE and prostate cancer persisted in multivariable analyses (adjusted odds ratio 1.90; 95% confidence interval 1.07-3.38, P = 0.028) while that with oropharyngeal cancer (adjusted odds ratio 3.63; 95% confidence interval 0.92-14.29, P = 0.066) was attenuated after adjusting for retained covariates of age, race, gastroesophageal reflux disease, hiatal hernia, and proton pump inhibitor use. Within the subset of patients with cancer, prior treatment with radiation or chemotherapy was not associated with BE. There were no significant differences between cases and controls in the proportions of subjects with several specific malignancies in first- or second-degree relatives. In conclusion, the risk of BE in men may be elevated with prior personal history of oropharyngeal or prostate cancer. However, prior cancer treatments and family history of cancer were not associated with increased risk of BE. Further studies are needed to elucidate if there is a causative relationship or shared risk factors between prostate cancer and BE.

Barrett's oesophagus: can meaningful screening and surveillance guidelines be formulated based on new data and rejigging the old paradigm?

Gastro-oesophageal reflux disease (GORD) and Barrett's oesophagus (BO) have been considered to be the most important known risk factors for oesophageal adenocarcinoma (OAC). It has been the fastest growing cancer in the Western World and has occurred against a backdrop of progressive reduction in the risk estimate of malignancy associated with BO and no reduction in mortality from OAC using the prevailing screening and surveillance guidelines. The recently published link between high risk HPV and Barrett's dysplasia/cancer may be the 'missing' strong risk factor responsible for the significant rise of OAC since the 1970's, as has been the case with head and neck tumours, another viral associated cancer. P53 immunohistochemistry has been proposed as a good molecular marker for predicting disease progression in BD. Nevertheless, significant negative staining for this mutation in BD remains a major hurdle to widespread routine clinical use as a sole molecular marker. Recent data raises the distinct possibility of at least 2 (probably more) carcinogenic pathways operating in OAC. One is HPV mediated devoid largely of p53 mutations and the other p53 dependent. The joint use of both these markers as part of a molecular panel may represent the best bet yet of detecting the high risk group of progressors to OAC. Patients who are positive for either or both biomarkers i.e p53 or/and transcriptional markers of HPV may warrant more intensive screening. In future, genome wide technology may provide molecular signatures to aid diagnosis and risk stratification in BO.

Familial clustering of Barrett's esophagus and esophageal adenocarcinoma in a European cohort

BACKGROUND & AIMS

Up to 7% of cases of Barrett's esophagus (BE) or esophageal adenocarcinoma (EAC) in the United States occur in family clusters. We identified first-degree and second-degree relatives of patients with BE and EAC to determine the extent of familial clustering in a European cohort and studied differences between familial and nonfamilial cases.

METHODS

A questionnaire was sent to all patients diagnosed with BE or EAC from 2000-2011 at 3 hospitals in the Netherlands (n = 838). Diagnoses of affected relatives were confirmed by using the Dutch Pathology Registry. Familial statuses of BE were defined as definitive (≥1 first-degree or second-degree relative with BE or EAC), possible (≥1 reported relative with BE or esophageal cancer without histologic confirmation), unlikely (no family history), or unknown.

RESULTS

A total of 603 patients with BE or EAC (71%) responded and were included in the analysis. Familial BE was definitive for 7% of cases (n = 39, 10% of first-degree relatives affected), possible for 6% (n = 36), unlikely for 49% (n = 297), and unknown for 38% (n = 231). Definitive cases of familial BE were younger at onset of heartburn and EAC diagnosis; their first-degree relatives more frequently had reflux symptoms and a prior upper endoscopy, compared with unlikely cases of familial BE.

CONCLUSIONS

In a database analysis of patients diagnosed with BE or EAC in the Netherlands, 7% of cases of BE and EAC were familial. These cases have a younger average age of onset of reflux symptoms and diagnosis of EAC than unlikely familial cases. These findings may indicate that genetic factors contribute to BE susceptibility, with a possible central role of gastroesophageal reflux.

Influence of Life Style Factors on Barrett's Oesophagus

Background. Since the incidence of adenocarcinoma of the oesophagus is rising, the prognosis is poor, and surveillance programs are expensive and mostly cost ineffective, there is a need to increase the knowledge of risk factors in Barrett's oesophagus and oesophageal cancer in order to be able to give attention to medical prevention and/or surveillance programs. Aim. To study if there is a correlation between the development of Barrett's oesophagus and GOR (gastro oesophageal reflux), family history of GOR, and life style factors, such as alcohol, smoking habits, and mental stress. Methods. Fifty-five consecutively selected patients with Barrett's oesophagus (BO) examined at Linköping University Hospital's Oesophageal Laboratory were matched by sex, age, and duration of reflux symptoms with 55 GOR patients without Barrett's oesophagus at the Oesophageal Laboratory. The medical charts in respective groups were examined for comparison of life style factors, mental stress, medication, duration of gastroesophageal acid reflux at 24 hr-pH-metry, and incidence of antireflux surgery and of adenocarcinoma of the oesophagus (ACO). Also, potential gender differences and diagnosis of ACO were studied. Results. Mean percentage reflux time on 24 hr-pH-metry was higher for the Barrett's oesophagus group, 18% for women and 17% for men compared to 4% for women and 4% for men in the control group (P < 0.05). Family history of GOR was more frequent in Barrett's oesophagus patients (62%) than in the control group (35%) (P < 0.05). Male patients with Barrett's oesophagus had medical therapy for their GOR symptoms to a higher extent (38%) than male controls (65%) (P < 0.05). No difference was found in the number of tobacco users or former tobacco users between Barrett's oesophagus patients and controls. Barrett's oesophagus patients had the same level of alcohol consumption and the same average BMI as the control subjects. Female patients with Barrett's oesophagus rated themselves as more mentally stressed (67%) than the female controls (38%) (P < 0.05). In the five-year medical chart follow-up, five of 55 patients developed adenocarcinoma among the Barrett's oesophagus patients, none in the control group. Conclusions. Long reflux time and family clustering of GOR seem to influence the development of Barrett's oesophagus. Smoking habits, alcohol consumption and BMI do not seem to have any impact on the development of Barrett's oesophagus.

Hereditary Factors in Esophageal Adenocarcinoma

BACKGROUND

The vast majority of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) cases are sporadic and caused by somatic mutations. However, over the last decades several families have been identified with clustering of EAC. Here, we review data from the published literature in order to address the current knowledge on familial EAC.

SUMMARY

Although familial EAC comprises a relatively small group of patients, it is a clinically relevant category due to the poor prognosis of this type of cancer. Efforts should be made to identify specific genetic risk factors for familial EAC to enable identification of relatives at risk, since endoscopic surveillance can diagnose preneoplastic or early neoplastic lesions leading to early treatment, with improved outcome.

KEY MESSAGE

Although familial EAC comprises a relatively small group of patients, this is a clinically relevant category due to the poor prognosis. Efforts should be made to identify specific genetic risk factors for familial EAC in order to facilitate the identification of other family members with a predisposition for this type of cancer.

PRACTICAL IMPLICATIONS

Approximately 7% of BE and EAC cases are considered familial. Age at diagnosis is generally lower for patients with familial EAC as compared to sporadic cases, while other known risk factors for EAC, such as male gender and Caucasian ethnicity, do not differ between the two groups. In several described families with clustering of EAC the pattern of inheritance seems to be consistent with a rare autosomal dominant genetic trait. However, some association has been found with (attenuated) familial adenomatous polyposis, mismatch repair deficiency and recently with the genes MSR1, ASCC1 and CTHRC1. Nevertheless, no specific genetic predisposition has yet been identified.

A genome-wide association study identifies new susceptibility loci for esophageal adenocarcinoma and Barrett's esophagus

Esophageal adenocarcinoma is a cancer with rising incidence and poor survival. Most such cancers arise in a specialized intestinal metaplastic epithelium, which is diagnostic of Barrett's esophagus. In a genome-wide association study, we compared esophageal adenocarcinoma cases (n = 2,390) and individuals with precancerous Barrett's esophagus (n = 3,175) with 10,120 controls in 2 phases. For the combined case group, we identified three new associations. The first is at 19p13 (rs10419226: P = 3.6 × 10(-10)) in CRTC1 (encoding CREB-regulated transcription coactivator), whose aberrant activation has been associated with oncogenic activity. A second is at 9q22 (rs11789015: P = 1.0 × 10(-9)) in BARX1, which encodes a transcription factor important in esophageal specification. A third is at 3p14 (rs2687201: P = 5.5 × 10(-9)) near the transcription factor FOXP1, which regulates esophageal development. We also refine a previously reported association with Barrett's esophagus near the putative tumor suppressor gene FOXF1 at 16q24 and extend our findings to now include esophageal adenocarcinoma.

Germline genetic contributions to risk for esophageal adenocarcinoma, Barrett's esophagus, and gastroesophageal reflux

BACKGROUND

Esophageal adenocarcinoma (EA) is an increasingly common cancer with poor survival. Barrett's esophagus (BE) is the main precursor to EA, and every year 0.12% to 0.5% of BE patients progress to EA. BE typically arises on a background of chronic gastroesophageal reflux (GERD), one of the risk factors for EA.

METHODS

We used genome-wide association data to investigate the genetic architecture underlying GERD, BE, and EA. We applied a method to estimate the variance explained (array heritability, h(2)g) and the genetic correlation (rg) between GERD, BE, and EA by considering all single nucleotide polymorphisms (SNPs) simultaneously. We also estimated the polygenic overlap between GERD, BE, and EA using a prediction approach. All tests were two-sided, except in the case of variance-explained estimation where one-sided tests were used.

RESULTS

We estimated a statistically significant genetic variance explained for BE (h(2)g = 35%; standard error [SE] = 6%; one-sided P = 1 × 10(-9)) and for EA (h(2)g = 25 %; SE = 5%; one-sided P = 2 × 10(-7)). The genetic correlation between BE and EA was found to be high (rg = 1.0; SE = 0.37). We also estimated a statistically significant polygenic overlap between BE and EA (one-sided P = 1 × 10(-6)), which suggests, together with the high genetic correlation, that shared genes underlie the development of BE and EA. Conversely, no statistically significant results were obtained for GERD.

CONCLUSIONS

We have demonstrated that risk to BE and EA is influenced by many germline genetic variants of small effect and that shared polygenic effects contribute to risk of these two diseases.

A study of pathophysiological factors associated with gastro-esophageal reflux disease in twins discordant for gastro-esophageal reflux symptoms

BACKGROUND

Differences in lower esophageal sphincter (LES) and peristaltic function and in transient LES relaxations (TLESR) have been described in patients with gastro-esophageal reflux disease (GERD). However, some of these differences may be the result of chronic GERD rather than being an underlying contributory factor.

METHODS

Twins discordant for GERD symptoms, i.e., only one twin had GERD symptoms, underwent standard LES and esophageal body manometry, and then using a sleeve sensor prolonged LES and pH monitoring, 30 min before and 60 min after a 250 mL 1200 kcal lipid meal.

KEY RESULTS

Eight monozygotic and 24 dizygotic female twins were studied. Although there was no difference in preprandial LES pressure (symptomatic 13.2 ± 7.1 mmHg vs asymptomatic 15.1 ± 6.2 mmHg, P = 0.4), LES pressure fell further postprandially in symptomatic twins (LES pressure area under the curve 465 ± 126 vs 331 ± 141 mmHg h, P < 0.01). 12/37 (32%) of acid reflux episodes in symptomatic twins occurred due to low LES pressure or deep inspiration/strain and 0/17 in asymptomatic twins (P = 0.01). There was no difference between symptomatic and asymptomatic twins in: peristaltic amplitude, ineffective esophageal body motility, hiatus hernia prevalence, or LES length. There was also no difference in TLESR frequency preprandially (symptomatic median 1(range 0-2) vs asymptomatic 0(0-2), P = 0.08) or postprandially (2.5(1-8) vs 3(1-6), P = 0.81).

CONCLUSIONS & INFERENCES

Twins with GERD symptoms had lower postprandial LES pressure and given the close genetic link between the twins, it is possible that such differences are caused by GERD. Acid reflux episodes associated with a hypotensive LES were seen in symptomatic, but not in asymptomatic twins.

How reflux causes symptoms: reflux perception in gastroesophageal reflux disease

In gastroesophageal reflux disease (GERD) symptoms arise due to reflux of gastric content into the oesophagus. However, the relation between magnitude and onset of reflux and symptom generation in GERD patients is far from simple; gastroesophageal reflux occurs several times a day in everyone and the majority of reflux episodes remains asymptomatic. This review aims to address the question how reflux causes symptoms, focussing on factors leading to enhanced reflux perception. We will highlight esophageal sensitivity variance between subtypes of GERD, which is influenced by peripheral sensitization of primary afferents, central sensitization of spinal dorsal horn neurons, impaired mucosal barrier function and genetic factors. We will also discuss the contribution of specific refluxate characteristics to reflux perception, including acidity, and the role of bile, pepsin and gas and proximal extent. Further understanding of reflux perception might improve GERD treatment, especially in current partial responders to therapy.

Risk of esophagitis among individuals born preterm or small for gestational age

BACKGROUND & AIMS

The association between gastroesophageal reflux and esophageal adenocarcinoma is likely to be mediated by inflammation. Reflux is common in infancy; the esophageal mucosa of infants born preterm or small for gestational age (SGA) could be particularly vulnerable. We investigated the association between preterm or SGA birth and risk of esophagitis early in life.

METHODS

We analyzed data from the Swedish birth register and the Swedish patient register to identify birth characteristics of individuals with endoscopically verified esophagitis from 1973 to 2007 and to determine their outcomes (7358 cases). Five controls were selected randomly and matched with each case (N = 38,479). Multivariable conditional logistic regression models were used to provide odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for potential confounding.

RESULTS

The risk of esophagitis was increased among individuals born preterm (≤32 gestational weeks) (OR, 2.74; 95% CI, 2.15-3.49) or SGA (OR, 1.49; 95% CI, 1.32-1.68). When data were stratified by age at diagnosis and by sex, different risk patterns appeared. Among individuals diagnosed with esophagitis 9 years of age and younger, the OR for prematurity was 6.82 (95% CI, 4.65-10.03) and the OR for SGA at birth was 1.98 (95% CI, 1.55-2.52). Furthermore, the association with preterm birth was stronger among males (OR, 9.88; 95%, CI 5.93-16.45) than females (OR, 3.41; 95% CI, 1.81-6.41), whereas the association with SGA was stronger among females (OR, 2.50; 95% CI, 1.76-3.55) than males (OR, 1.64; 95% CI, 1.16-2.30). The risk of being diagnosed with esophagitis at age 20 or younger was not associated with preterm birth (OR, 1.02; 95% CI, 0.64-1.63), but was associated with being SGA at birth (OR, 1.31; 95% CI, 1.11-1.54).

CONCLUSIONS

Preterm birth is associated with esophagitis only during childhood, whereas SGA birth is associated with esophagitis during adolescence as well. The associations appear to differ between sexes.

Endoscopic esophagitis is more severe in gastroesophageal reflux patients with a positive family history

BACKGROUND

The role of genetic factors in the etiology of gastroesophageal reflux disease (GERD) is still uncertain.

AIM

To define whether the presence of reflux symptoms in first-degree relatives can affect the severity of the endoscopic picture of patients with GERD and disease evolution during follow-up.

PATIENTS/METHODS

A total of 1930 consecutive patients with GERD were referred for endoscopy from Trikala prefecture, had an entry endoscopy and a follow-up if needed. Before endoscopic evaluation, all patients and their first-degree relatives completed Reflux Symptom Questionnaire. Patients were followed up for 4 years with Reflux Symptom Questionnaire every 6 months.

RESULTS

A total of 258 (62.9%) patients with positive and 724 (47.6%) with negative family history of GERD had esophagitis (P<0.0001). Seventy-six (74.5%) patients with more than 1 family member with GERD had esophagitis (P<0.0001). During follow-up endoscopic picture was aggravated in 101 (25%) patients with positive and 46 (3%) with negative family history. A total of 359 (24%) of GERD patients with negative and 24 (10%) with positive family history managed to stop proton pump inhibitors during follow-up (P<0.0001). In logistic regression analysis: age, male sex, presence of hiatal hernia, family history of GERD, tranquilizer use, frequency, and duration of reflux symptoms were independently associated with presence of esophagitis.

CONCLUSIONS

Although we cannot overlook the importance of confounding factors such as body weight and/or psychological factors, we found that endoscopic picture is more severe among GERD patients with at least 1 first-degree relative with GERD. During follow-up, patients with negative family history had more chances to wean off proton pump inhibitors after life-style modifications.

History of cancer in first degree relatives of Barrett's esophagus patients: a case-control study

BACKGROUND AND OBJECTIVE

Familial clusters of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have been reported. This study evaluates the history of cancer in BE patients families.

METHODS

In two years, patients with BE (272), esophagitis (456) and controls (517) were recruited in 12 Italian Endoscopy Units. Cancer family history in first-degree (FD) relatives was determined by a questionnaire.

RESULTS

Approximately 53% of BE, 51% of esophagitis, and 48% of controls had at least one relative affected by any type of malignancy. Probands with at least one esophageal or gastric (E/G) cancer-affected relative showed a BE risk which was at least eighty-five percent higher than that of probands without affected relatives. The relative risk of BE was 4.18, 95% CL=0.76-23.04 if a FD relative had early (mean age ≤ 50 years) onset E/G cancer compared to late onset E/G cancer.

CONCLUSION

In this sample there was no evidence that a family history of cancer was associated with the diagnosis of BE. An intriguing result was the association between the occurrence of E/G cancers at earlier ages (< 50 years) among BE relatives with respect the control group. This could suggest a genetic contribution in onset of these tumors, but the sample was too small to demonstrate a significant association. Further exploration of family history of E/G cancer and a diagnosis of BE in larger samples is warranted.

Functional single-nucleotide polymorphism of epidermal growth factor is associated with the development of Barrett's esophagus and esophageal adenocarcinoma

Reflux esophagitis (RO) and Barrett's esophagus (BO) can cause esophageal adenocarcinoma (OAC). The esophageal mucosa in the RO-BO-OAC cascade is chronically exposed to gastro-esophageal reflux. Epidermal growth factor (EGF) has an important role in the protection and repair of mucosal damage, and non-physiologic levels are associated with gastrointestinal tumors. The aim is to determine the functional effect of EGF gene polymorphisms on RO, BO and OAC development. A cohort of 871 unrelated Dutch Caucasians consisted of 198 healthy controls, 298 RO patients, 246 BO patients and 129 OAC patients. The frequency of the EGF-production-associated 5'UTR A+61G polymorphism was determined in these four groups. EGF immunohistochemistry was performed on BO biopsies. EGF expression was significantly lower in the G/G genotype compared with the A/G (P=0.008) and A/A (P=0.002) group. The G/G genotype was significantly more prevalent in RO (odds ratios (OR)=2.6; 95% confidence intervals (95% CI): 1.3-5.2), BO (OR=3.0; 95% CI: 1.5-6.2) and OAC (OR=4.1; 95% CI: 1.8-9.7) than in controls. The G allele is associated with reduced EGF expression and increased risk for RO, BO and OAC development. This indicates that reduced mucosal protection resulting from genetically decreased EGF expression enhances esophageal tumor development.

Barrett's oesophagus in Asians--are ethnic differences due to genes or the environment?

Ethnic differences in the prevalence of gastro-oesophageal reflux disease (GORD) and its complications, including Barrett's oesophagus (BO), are well described in multiracial Asian patient populations. These findings together with familial aggregation of GORD symptoms and twin studies suggest the possibility of a genetic component to GORD. Nevertheless, environmental factors, e.g. Helicobacter pylori infection, abdominal adiposity and metabolic syndrome, could equally account for these differences. Indian (South Asian) race is a risk factor for Barrett' oesophagus. This may be related to the Caucasian genetic make-up of Indians as opposed to an Oriental one as is the case of most other Asians. The HLA-B07 gene commonly found in South Asian and Caucasian populations, but not Orientals, may confer an increased risk for BO. Nevertheless, the high prevalence of H. pylori in South Asians and the consequent atrophic gastritis and hypochlorhydria may partially ameliorate this genetic predisposition to BO. The higher prevalence of obesity and the metabolic syndrome amongst certain Asiatic races may also contribute to the observed increased risk for BO. Future research should target the search for GORD/BO genes, ethnic differences in parietal cell mass and hiatal hernia, H. pylori colonization factors (e.g. MUC1 and MUC2) and adhesion molecules (BabA). Racial differences in lifestyle factors, i.e. abdominal adiposity, consumption of fruit and vegetables as well as smoking, should all be investigated as potential causes for this interethnic variation in GORD and BO. Nature or nurture, the clues are teasing and tantalizing and illustrate the complex relationship between the genetic make-up of man and the environment.

Prevalence of Barrett esophagus in first-degree relatives of patients with esophageal adenocarcinoma

AIM

The aim of this study is to determine the prevalence of Barrett esophagus (BE) in first-degree relatives of patients with esophageal adenocarcinoma (EAC) and Barrett high-grade dysplasia (HGD).

METHODS

After Institutional Review Board approval, first-degree relatives of patients with EAC/HGD underwent unsedated ultrathin transnasal endoscopy (UUTNE) with biopsy. BE was suspected if any salmon-colored epithelial tongues were seen above the gastroesophageal junction. A diagnosis of BE was made only if biopsy from these areas confirmed columnar-lined epithelium with intestinal metaplasia.

RESULTS

From 23 families, 47 first-degree relatives underwent ultrathin transnasal endoscopy and 1 patient underwent routine upper endoscopy with sedation as part of this study. The mean age of cases was 44.4 years. All patients tolerated the procedure well and there were no procedure-related complications. BE was suspected in 16 (34%) patients and confirmed in 13 of 16 (27.7%) patients. There were 4 long segments (>3 cm) and 9 short segments (<3 cm) of BE.

CONCLUSION

There is a significantly higher than expected prevalence of BE in first-degree relatives of patients with EAC/HGD. This should be taken in to consideration to develop further screening guidelines. Further work is needed to confirm these findings. Unsedated transnasal endoscopy is a safe and well-tolerated method for BE screening.

New strategies in Barrett's esophagus: integrating clonal evolutionary theory with clinical management

Barrett's esophagus is a condition in which the normal stratified squamous epithelium of the distal esophagus is replaced by intestinal metaplasia. For more than three decades, the prevailing clinical paradigm has been that Barrett's esophagus is a complication of symptomatic reflux disease that predisposes to esophageal adenocarcinoma. However, no clinical strategy for cancer prevention or early detection based on this paradigm has been proven to reduce esophageal adenocarcinoma mortality in a randomized clinical trial in part because only about 5% to 10% of individuals with Barrett's esophagus develop esophageal adenocarcinoma. Recent research indicates that Barrett's metaplasia is an adaptation for mucosal defense in response to chronic reflux in most individuals. The risk of progressing to esophageal adenocarcinoma is determined by development of genomic instability and dynamic clonal evolution in the distal esophagus modulated by host and environmental risk and protective factors, including inherited genotype. The challenge for investigators of Barrett's esophagus lies in integrating knowledge about genomic instability and clonal evolution into clinical management to increase the lifespan and quality of life of individuals with this condition.

Cigarette smoking and its association with overlapping gastroesophageal reflux disease, functional dyspepsia, or irritable bowel syndrome

BACKGROUND

Gastroesophageal reflux disease (GERD), functional dyspepsia (FD), and irritable bowel syndrome (IBS) are common gastrointestinal diseases. Several studies have shown a significant occurrence of overlap among these 3 diseases. The purpose of this study was to examine the factors associated with such disease overlap in Japanese adults.

METHODS

We performed a cross-sectional study on Japanese workers who visited a clinic for a routine health check-up and asked them to fill out a self-report questionnaire. GERD was defined as episodes of heartburn and/or acid regurgitation at least once a week, and the diagnosis of FD and IBS was based on Rome III criteria. A logistic regression model was used to identify risk factors, and odds ratio (OR) was calculated with 95% confidence intervals (CIs).

RESULTS

Disease overlaps were found in 160 (6.0%) of the 2680 eligible subjects. Female gender was associated with GERD + IBS (OR=1.99; 95% CI, 1.06-3.75), and FD + IBS (OR=1.72; 95% CI, 1.03-2.85), and lower body mass index was negatively associated with FD + IBS (OR=0.54; 96% CI, 0.34-0.87). Cigarette smoking was a common factor associated with the overlaps: GERD + FD (OR=2.14; 95% CI, 1.22-3.76), GERD + IBS (OR=3.16; 95% CI, 1.75-3.71), FD + IBS (OR=2.26; 95% CI, 1.40-3.66), and GERD + FD + IBS (OR=4.08; 95% CI, 1.66-10.07). The associations between smoking habits and overlaps were stronger in smokers who smoked ≥1 pack per day as compared to those who smoked <1 pack per day.

CONCLUSION

Cigarette smoking was significantly associated with overlaps among GERD, FD, and IBS in Japanese adults.

The pathogenesis of Barrett's metaplasia and the progression to esophageal adenocarcinoma

The most important risk factor for the development of Barrett's esophagus is the reflux of both gastric and duodenal contents into the esophagus. The reason why Barrett's metaplasia develops only in a minority of patients suffering from gastroesophageal reflux disease remains unknown.The exact mechanism behind the transition of normal squamous epithelium into specialized columnar epithelium is also unclear. It is likely that stem cells are involved in this metaplastic change, as they are the only permanent residents of the epithelium. Several tumorigenic steps that lead to the underlying genetic instability, which is indispensable in the progression from columnar metaplasia to esophageal adenocarcinoma have been described. This review outlines the process of pathogenesis of Barrett's metaplasia and its progression to esophageal adenocarcinoma.

Barrett esophagus: an update

Many developments have been made in the field of Barrett esophagus that have tremendous clinical implications. There are new definitions of Barrett esophagus that have had an immediate clinical impact on cancer risk and screening. Of interest is the definition by the British Society of Gastroenterology, which does not require the presence of intestinal metaplasia for a diagnosis of Barrett esophagus. Imaging techniques that allow improved visualization of intestinal metaplasia at the cellular level are now being used in clinical practice. New hypotheses elucidating the progression from squamous epithelium to intestinal metaplasia have been proposed. Indeed, the crucial role that transcription factors have in the pathogenesis of Barrett esophagus has been clarified. Improved characterization of the molecular mechanisms underlying Barrett esophagus is an incentive to undertake more basic science research in this field. Such research could also help with the development of chemoprevention strategies for this precancerous condition. This Review discusses the advances in understanding of the pathogenesis, diagnosis and treatment of Barrett esophagus.

Different characteristics of patients with gastro-oesophageal reflux disease on their path through healthcare: a population follow-up study

BACKGROUND

Only a minority of patients with gastro-oesophageal reflux symptoms (GORS) seek medical advice. Little is known about patient characteristics associated with consultation in primary care and referral to secondary care.

AIMS AND METHODS

We compared the characteristics of patients with GORS in the general population, those who consulted their general practitioner (GP) and those referred to secondary care for upper endoscopy. We aimed to identify differences between patients with short term (<90 days) and chronic symptoms, and differences between patients with symptoms in primary and secondary care. The study was performed in a primary care based prospective dynamic population.

RESULTS

In total, 16% of 7237 adult patients were identified with GORS. Twenty-five percent of these patients consulted the GP, of whom 40% were referred for endoscopy. Patients with chronic GORS were older, had a higher body mass index, were more often referred for upper endoscopy (all P<0.001) and more frequently had relevant findings during endoscopy (oesophagitis: 50% and Barrett's oesophagus: 10%). Patients referred for upper endoscopy were older than nonreferred patients (P<0.001).

CONCLUSION

Only a minority of people with GORS visit their GP. After consulting referral for endoscopy occurs relatively often. Underlying endoscopic abnormalities are frequently found in patients with chronic GORS.

Gender-related differences in upper gastrointestinal endoscopic findings: an assessment of 4,700 cases from Iran

BACKGROUND AND OBJECTIVE

Regarding the high prevalence of gastrointestinal symptoms in our country, the probable overuse or even late usage of upper gastrointestinal endoscopy for unnecessary reasons and gender influences on both internal and external fate and effects, we decided to evaluate the gender-related differences in upper gastrointestinal endoscopic findings to provide gastroenterologists with information which they can perform better interpretation of their patient's symptoms before performing upper gastrointestinal endoscopy.

DESIGN

A descriptive cross-sectional study performed to evaluate gender-related differences in the upper endoscopy findings.

SETTING

The study was performed in the upper endoscopy ward of a general hospital in Tehran, Iran.

PATIENTS

Four thousand and seven hundred Iranian patients undergo upper endoscopy between 1992 and 2002.

MAIN OUTCOME MEASUREMENTS

Upper endoscopy findings

RESULTS

After age adjustment, oesophageal tumour, gastroesophageal reflux disease (GERD), gastric tumour, oesophageal varices, gastritis, hiatal hernia, gastric ulcer and erosive gastropathy, all p < 0.001 were significantly more common among men rather than women. Male gender predicts the presence of hiatal hernia (odds ratio (OR) = 1.9, p < 0.001), GERD (OR = 1.6, p < .001), gastric ulcer (OR = 2.3, p < 0.001), duodenal ulcer (OR = 2.3, p < 0.001) and duodenal varices (OR = .6, p = .044).

LIMITATION

Backward study

CONCLUSION

Our regression models revealed that male gender is a risk factor for hiatal hernia, GERD, gastric ulcer and duodenal ulcer but not for other upper endoscopic findings.

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

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

The obesity epidemic

Obesity has reached epidemic proportions in the United States, with 35.1% of adults being classified as obese. Obesity affects every segment of the US population and continues to increase steadily, especially in children. Obesity increases the risk for many other chronic diseases, including diabetes mellitus, cardiovascular disease, and nonalcoholic fatty liver disease, and decreases overall quality of life. The current US generation may have a shorter life expectancy than their parents if the obesity epidemic is not controlled, and there is no indication that the prevalence of obesity is decreasing. Because of the complexity of obesity, it is likely to be one of the most difficult public health issues our society has faced.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

Role of obesity in Barrett's esophagus and cancer

The incidence of esophageal adenocarcinoma (EAC) has increased dramatically in the western world, and there also appears to have been an increase in the incidence of Barrett's esophagus and gastroesophageal reflux disease in recent years. The contemporaneous increase in obesity has focused interest on whether obesity is a risk factor for EAC and its precursors. This article reviews current evidence for the role that overweight/obesity and body fat distribution have in development of the esophagitis metaplasia-dysplasia-adenocarcinoma sequence. Particular attention is paid to the stage at which adiposity may act to influence the risk of EAC, because this determines the importance of weight control and weight loss at each stage in the disease spectrum for the prevention of EAC.

Gastroesophageal reflux disease is associated with the C825T polymorphism in the G-protein beta3 subunit gene (GNB3)

OBJECTIVES

Visceral hypersensitivity is involved in the etiology of reflux symptoms. Familial clustering and twin studies demonstrated a genetic predisposition to gastroesophageal reflux disease (GERD). G-protein-coupled receptors (GPCRs) mediate the response to acid, neurotransmitters and humoral factors modulating esophageal sensory function. Thus, polymorphisms in G-proteins are putative genetic factors contributing to GERD manifestation. A functional polymorphism in the G-protein beta3 subunit gene (GNB3) is associated with functional dyspepsia (FD), in which visceral hypersensitivity is implicated in symptom generation. We evaluated the association of the GNB3 C825T polymorphism with GERD and GERD subgroups classified according to esophageal acid exposure time, symptom-reflux correlation, or coexistence of FD and/or irritable bowel syndrome (IBS) symptoms.

METHODS

In total, 363 GERD patients, defined as having esophageal pH < 4 > or = 6% of time and/or symptom index (SI) > or = 50% or symptom association probability (SAP) > or = 95%, participated. In addition, 373 healthy controls free of gastrointestinal symptoms were studied. Genotyping was performed by molecular beacon assay.

RESULTS

The CT genotype was more prevalent in GERD patients relative to healthy controls (adjusted odds ratio (OR)=1.43, 95% CI 1.04-1.98). GERD patients sensitive to physiological amounts of reflux displayed a higher OR (1.59), as did GERD patients with a positive symptom association score (1.50). The strongest association was detected in patients without concomitant FD and/or IBS symptoms (OR=1.66).

CONCLUSIONS

GERD is associated with GNB3 C825T. The results for GERD subgroups support the hypothesis that enhanced perception of reflux events, as a consequence of the increased signal transduction upon GPCR activation associated with the 825T allele, underlies this association.

Barrett's esophagus and esophageal adenocarcinoma in adults: long-term GERD or something else?

Esophageal adenocarcinoma (EAC) is a highly lethal tumor and is currently the most rapidly rising incidence cancer in the Western world. Numerous risk factors in the development of Barrett's esophagus (BE) (a precursor of EAC) and EAC itself have been identified and are likely multifactorial. Gastroesophageal reflux disease (GERD) is a significant risk factor for BE and EAC; however, only a minority of patients with chronic GERD actually develop BE. Thus, other risk factors that modulate reflux-related inflammatory and neoplastic effects on esophageal epithelium must exist. Epidemiologic data have prompted initiation of chemopreventive trials using aspirin and proton pump inhibitors in the treatment of BE and EAC. Further research should also clarify the role of risk factors such as ethnicity and obesity in BE and EAC development and progression. Identification of prognostic factors would allow better risk stratification of patients and ultimately impact the rising incidence of EAC.

Functional heartburn, nonerosive reflux disease, and reflux esophagitis are all distinct conditions—A debate: Pro

Gastroesophageal reflux disease (GERD) traditionally has been approached as a spectrum-continuum, suggesting that patients may progress over time and develop a more severe esophageal mucosal involvement. The spectrum-continuum conceptual model had a profound impact on the research priorities in GERD, as well as on proposed diagnostic algorithms and therapeutic strategies. Natural course studies in GERD are almost always retrospective and commonly afflicted with a plethora of shortcomings. Factors that affect quality of natural course studies in GERD include the following: index endoscopy results are taken at face value; antireflux treatment is consumed until index endoscopy and/or offered during the follow-up phase; pathophysiologic, anatomic, and genetic factors are overlooked; and lack of confirmation of the durability of the new esophageal mucosal finding. Functional heartburn is common and likely to affect a large subset of patients presenting with heartburn. Evidence to support progression of functional heartburn to nonerosive reflux disease (NERD), erosive esophagitis, or Barrett's esophagus is very scarce. The largest population-based or longest-duration natural course studies report that only 10% of patients progress from NERD to erosive esophagitis over time. The other GERD patients remained within their respective phenotypic presentations of GERD.

Genetics of gastroesophageal cancer: paradigms, paradoxes, and prognostic utility

Hereditary diffuse gastric cancer and tylosis are autosomal dominant cancer susceptibility syndromes. Accumulating evidence also suggests a genetic contribution to Barrett's esophagus and adenocarcinoma, traditionally considered acquired disorders. In this article we review the current knowledge on the genetic mechanisms underlying hereditary diffuse gastric cancer, tylosis, and Barrett's esophagus. Hereditary diffuse gastric cancer is a paradigm for hereditary cancer susceptibility syndromes with E-cadherin implicated as the dominant oncogene in up to one-third of cases. Tylosis in contrast remains the paradox as whilst the putative abnormality has been localized to the long arm of chromosome 17, sequencing of this region has failed to reveal a disease causing mutation. In the case of Barrett's esophagus and adenocarcinoma, although a validated specific disease-associated gene is yet to be identified, the increasing body of evidence of a possible genetic link is paving the way for subsequent prognostic studies such as AspECT (Aspirin Esomeprazole Chemoprevention Trial). For the clinician these advances in understanding are already having implications for practice in terms of improved screening and the stratification of management strategies. As the mechanisms continue to be defined, there is the real possibility that these mechanisms could be exploited or subverted in the design of new therapies. In the meantime, however, clinicians should undertake rigorous biopsy programs to ensure early invasive lesions are detected.

Environmental factors in the etiology of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is currently one of the most common health problems in the Western world, affecting up to 20% of the adult population weekly and 50% monthly. It generates substantial suffering among patients as well as significant costs to both patients and society in general. GERD can further result in serious complications such as esophageal strictures, Barrett's esophagus and esophageal adenocarcinoma. This review discusses the current knowledge on risk factors and potential protective factors in the development of GERD.

Impact of changing epidemiology of gastroesophageal reflux disease on its diagnosis and treatment

Gastroesophageal reflux disease (GERD) has emerged as one of the most common diseases in modern civilization. This article reviews selected changes in epidemiology of GERD during the past decade and provides information on treatment options with a focus on the impact of GERD and potential role of laparoscopic antireflux surgery in patients with diabetes mellitus, obesity, liver cirrhosis, at the extremes of life age and in immunocompromised individuals such as liver and lung transplant recipients.

Influence of genetics on irritable bowel syndrome, gastro-oesophageal reflux and dyspepsia: a twin study

BACKGROUND

A genetic contribution has been proposed for irritable bowel syndrome (IBS) and gastro-oesophageal reflux disease (GERD), but is controversial. No twin data exist for dyspepsia.

AIM

To determine the relative contribution of genetic factors in GERD, dyspepsia (upper abdominal pain) and IBS.

METHODS

A total of 986 twin pairs (from initial mail-out response 51%). Both members completed validated symptom and psychological questionnaires; 481 monozygotic pairs [mean (s.d.) age 53 +/- 5.8 years] and 505 dizygotic pairs (mean age 54 +/- 5.6 years).

RESULTS

Prevalence of IBS, dyspepsia and GERD was 12%, 10% and 20%, respectively. Polychoric correlation for monozygotic twins for IBS (0.47) and GERD (0.44) were both substantially larger than those for dizygotic twins (0.17 and -0.37, respectively). Polychoric correlation was slightly lower in monozygotic than dizygotic twins for dyspepsia. Genetic modelling confirmed the independent additive genetic effects in GERD and IBS but not dyspepsia. Estimates of genetic variance were 22% for IBS, 13% for GERD and 0% for dyspepsia, but adjusting for anxiety and depression removed the statistical significance for IBS and GERD.

CONCLUSIONS

There is a genetic contribution to GERD and IBS but not dyspepsia; this may be mediated by the hereditability of anxiety and depression.

Prevalence of epigastric pain, heartburn and acid regurgitation in adolescents and their parents: evidence for intergenerational association

BACKGROUND AND AIMS

Little is known of the epidemiology of upper gastrointestinal symptoms in adolescents. We examined the prevalence of, and the risk factors for, epigastric pain, heartburn and acid regurgitation in adolescents from Northern Ireland.

PARTICIPANTS

A total of 1133 adolescents aged 12-18 years participated in this study.

METHODS

Questionnaires were mailed to 2017 randomly selected individuals gathering information on symptoms of epigastric pain, heartburn and acid regurgitation. Prevalences of the symptoms in the individuals and their parents were calculated. Associations between potential risk factors such as age, sex, body mass index category, smoking and frequency of symptoms were examined for both adolescents and their parents. Logistic regression was used to examine the relationship between adolescent and parental symptoms.

RESULTS

Symptoms of epigastric pain, heartburn and acid regurgitation were infrequent in adolescents, but were substantially more common in parents. Adolescents were more likely to experience these symptoms if either parent experienced them, the association being much stronger if both parents were symptomatic, for example, the odds ratio (95% confidence interval) for the individual having acid regurgitation if both parents had this symptom was 6.89 (1.32, 35.7). Symptoms were more likely in adolescents who smoked and whose parents smoked, who were from lower socioeconomic backgrounds, and who had higher body mass index. For parents, smoking was positively associated with all symptoms, whereas being overweight was related to frequency of heartburn and acid regurgitation.

CONCLUSIONS

Strong relationships were seen between adolescent and parental reporting of dyspeptic symptoms. Although this could be due to intrafamilial clustering of environmental factors, the associations persisted after adjusting for these. Psychosocial factors or genetic predisposition may underlie the relationships. Further research is required to explore these relationships more fully.