The Effect of Endoscopic Surveillance in Patients With Barrett's Esophagus: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Guidelines recommend endoscopic surveillance of patients with Barrett's esophagus (BE) to identify those with dysplasia (a precursor of carcinoma) or early-stage esophageal adenocarcinoma (EAC) who can be treated endoscopically. However, it is unclear whether surveillance increases survival times of patients with BE. We performed a systematic review and meta-analysis to qualitatively and quantitatively examine evidence for the association of endoscopic surveillance in patients with BE with survival and other outcomes.

METHODS

We searched publication databases for studies reporting the effects of endoscopic surveillance on mortality and other EAC-related outcomes. We reviewed randomized controlled trials, case-control studies, studies comparing patients with BE who received regular surveillance with those who did not receive regular surveillance, and studies comparing outcomes of patients with surveillance-detected EAC vs symptom-detected EACs. We performed a meta-analysis of surveillance studies to generate summary estimates using a random effects model. The primary aim was to examine the association of BE surveillance on EAC-related mortality. Secondary aims were to examine the association of BE surveillance with all-cause mortality and EAC stage at time of diagnosis.

RESULTS

A single case-control study did not show any association between surveillance and EAC-related mortality. A meta-analysis of 4 cohort studies found that lower EAC-related and all-cause mortality were associated with regular surveillance (relative risk, 0.60; 95% CI, 0.50-0.71; hazard ratio, 0.75; 95% CI, 0.59-0.94). Meta-analysis of 12 cohort studies showed lower EAC-related and all-cause mortality among patients with surveillance-detected EAC vs symptom-detected EAC (relative risk, 0.73; 95% CI, 0.57-0.94; hazard ratio, 0.59; 95% CI, 0.45-0.76). Lead- and length-time bias adjustment substantially attenuated/eliminated the observed benefits. Surveillance was associated with detection of EAC at earlier stages. A randomized trial is underway to evaluate the effects of endoscopic surveillance on mortality in patients with BE.

CONCLUSIONS

In a systematic review and meta-analysis of the effects of surveillance in patients with BE, surveillance as currently performed was associated with detection of earlier-stage EAC and may provide a small survival benefit. However, the effects of confounding biases on these estimates are not fully defined and may completely or partially explain the observed differences between surveyed and unsurveyed patients.

Association of sporadic and familial Barrett's esophagus with breast cancer

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC). Based on striking aggregation of breast cancer and BE/EAC within families as well as shared risk factors and molecular mechanisms of carcinogenesis, we hypothesized that BE may be associated with breast cancer. Pedigree analysis of families identified prospectively at multiple academic centers as part of the Familial Barrett's Esophagus Consortium (FBEC) was reviewed and families with aggregation of BE/EAC and breast cancer are reported. Additionally, using a matched case-control study design, we compared newly diagnosed BE cases in Caucasian females with breast cancer (cases) to Caucasian females without breast cancer (controls) who had undergone upper endoscopy (EGD). Two familial pedigrees, meeting a stringent inclusion criterion, manifested familial aggregation of BE/EAC and breast cancer in an autosomal dominant inheritance pattern with incomplete penetrance. From January 2008 to October 2016, 2812 breast cancer patient charts were identified, of which 213 were Caucasian females who underwent EGD. Six of 213 (2.82%) patients with breast cancer had pathology-confirmed BE, compared to 1 of 241 (0.41%) controls (P-value < 0.05). Selected families with BE/EAC show segregation of breast cancer. A breast cancer diagnosis is marginally associated with BE. We postulate a common susceptibility between BE/EAC and breast cancer.

Percutaneous transhepatic vs. endoscopic retrograde biliary drainage for suspected malignant hilar obstruction: study protocol for a randomized controlled trial

Background

The optimal approach to the drainage of malignant obstruction at the liver hilum remains uncertain. We aim to compare percutaneous transhepatic biliary drainage (PTBD) to endoscopic retrograde cholangiography (ERC) as the first intervention in patients with cholestasis due to suspected malignant hilar obstruction (MHO).

Methods

The INTERCPT trial is a multi-center, comparative effectiveness, randomized, superiority trial of PTBD vs. ERC for decompression of suspected MHO. One hundred and eighty-four eligible patients across medical centers in the United States, who provide informed consent, will be randomly assigned in 1:1 fashion via a web-based electronic randomization system to either ERC or PTBD as the initial drainage and, if indicated, diagnostic procedure. All subsequent clinical interventions, including crossover to the alternative procedure, will be dictated by treating physicians per usual clinical care. Enrolled subjects will be assessed for successful biliary drainage (primary outcome measure), adequate tissue diagnosis, adverse events, the need for additional procedures, hospitalizations, and oncological outcomes over a 6-month follow-up period. Subjects, treating clinicians and outcome assessors will not be blinded.

Discussion

The INTERCPT trial is designed to determine whether PTBD or ERC is the better initial approach when managing a patient with suspected MHO, a common clinical dilemma that has never been investigated in a randomized trial.

Trial registration

ClinicalTrials.gov, Identifier: NCT03172832. Registered on 1 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2473-2) contains supplementary material, which is available to authorized users.

A Prospective Multicenter Study Evaluating Learning Curves and Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography Among Advanced Endoscopy Trainees: The Rapid Assessment of Trainee Endoscopy Skills Study

BACKGROUND & AIMS

On the basis of the Next Accreditation System, trainee assessment should occur on a continuous basis with individualized feedback. We aimed to validate endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) learning curves among advanced endoscopy trainees (AETs) by using a large national sample of training programs and to develop a centralized database that allows assessment of performance in relation to peers.

METHODS

ASGE recognized training programs were invited to participate, and AETs were graded on ERCP and EUS exams by using a validated competency assessment tool that assesses technical and cognitive competence in a continuous fashion. Grading for each skill was done by using a 4-point scoring system, and a comprehensive data collection and reporting system was built to create learning curves by using cumulative sum analysis. Individual results and benchmarking to peers were shared with AETs and trainers quarterly.

RESULTS

Of the 62 programs invited, 20 programs and 22 AETs participated in this study. At the end of training, median number of EUS and ERCP performed/AET was 300 (range, 155-650) and 350 (125-500), respectively. Overall, 3786 exams were graded (EUS, 1137; ERCP-biliary, 2280; ERCP-pancreatic, 369). Learning curves for individual end points and overall technical/cognitive aspects in EUS and ERCP demonstrated substantial variability and were successfully shared with all programs. The majority of trainees achieved overall technical (EUS, 82%; ERCP, 60%) and cognitive (EUS, 76%; ERCP, 100%) competence at conclusion of training.

CONCLUSIONS

These results demonstrate the feasibility of establishing a centralized database to report individualized learning curves and confirm the substantial variability in time to achieve competence among AETs in EUS and ERCP. ClinicalTrials.gov: NCT02509416.

Genomic regions associated with susceptibility to Barrett's esophagus and esophageal adenocarcinoma in African Americans: The cross BETRNet admixture study

Background

Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) are far more prevalent in European Americans than in African Americans. Hypothesizing that this racial disparity in prevalence might represent a genetic susceptibility, we used an admixture mapping approach to interrogate disease association with genomic differences between European and African ancestry.

Methods

Formalin fixed paraffin embedded samples were identified from 54 African Americans with BE or EAC through review of surgical pathology databases at participating Barrett’s Esophagus Translational Research Network (BETRNet) institutions. DNA was extracted from normal tissue, and genotyped on the Illumina OmniQuad SNP chip. Case-only admixture mapping analysis was performed on the data from both all 54 cases and also on a subset of 28 cases with high genotyping quality. Haplotype phases were inferred with Beagle 3.3.2, and local African and European ancestries were inferred with SABER plus. Disease association was tested by estimating and testing excess European ancestry and contrasting it to excess African ancestry.

Results

Both datasets, the 54 cases and the 28 cases, identified two admixture regions. An association of excess European ancestry on chromosome 11p reached a 5% genome-wide significance threshold, corresponding to -log₁₀(P) = 4.28. A second peak on chromosome 8q reached -log₁₀(P) = 2.73. The converse analysis examining excess African ancestry found no genetic regions with significant excess African ancestry associated with BE and EAC. On average, the regions on chromosomes 8q and 11p showed excess European ancestry of 15% and 20%, respectively.

Conclusions

Chromosomal regions on 11p15 and 8q22-24 are associated with excess European ancestry in African Americans with BE and EAC. Because GWAS have not reported any variants in these two regions, low frequency and/or rare disease associated variants that confer susceptibility to developing BE and EAC may be driving the observed European ancestry association evidence.

Identification of a key role of widespread epigenetic drift in Barrett's esophagus and esophageal adenocarcinoma

Background

Recent studies have identified age-related changes in DNA methylation patterns in normal and cancer tissues in a process that is called epigenetic drift. However, the evolving patterns, functional consequences, and dynamics of epigenetic drift during carcinogenesis remain largely unexplored. Here we analyze the evolution of epigenetic drift patterns during progression from normal squamous esophagus tissue to Barrett’s esophagus (BE) to esophageal adenocarcinoma (EAC) using 173 tissue samples from 100 (nonfamilial) BE patients, along with publically available datasets including The Cancer Genome Atlas (TCGA).

Results

Our analysis reveals extensive methylomic drift between normal squamous esophagus and BE tissues in nonprogressed BE patients, with differential drift affecting 4024 (24%) of 16,984 normally hypomethylated cytosine-guanine dinucleotides (CpGs) occurring in CpG islands. The majority (63%) of islands that include drift CpGs are associated with gene promoter regions. Island CpGs that drift have stronger pairwise correlations than static islands, reflecting collective drift consistent with processive DNA methylation maintenance. Individual BE tissues are extremely heterogeneous in their distribution of methylomic drift and encompass unimodal low-drift to bimodal high-drift patterns, reflective of differences in BE tissue age. Further analysis of longitudinally collected biopsy samples from 20 BE patients confirm the time-dependent evolution of these drift patterns. Drift patterns in EAC are similar to those in BE, but frequently exhibit enhanced bimodality and advanced mode drift. To better understand the observed drift patterns, we developed a multicellular stochastic model at the CpG island level. Importantly, we find that nonlinear feedback in the model between mean island methylation and CpG methylation rates is able to explain the widely heterogeneous collective drift patterns. Using matched gene expression and DNA methylation data in EAC from TCGA and other publically available data, we also find that advanced methylomic drift is correlated with significant transcriptional repression of ~ 200 genes in important regulatory and developmental pathways, including several checkpoint and tumor suppressor-like genes.

Conclusions

Taken together, our findings suggest that epigenetic drift evolution acts to significantly reduce the expression of developmental genes that may alter tissue characteristics and improve functional adaptation during BE to EAC progression.

Electronic supplementary material

The online version of this article (10.1186/s13148-017-0409-4) contains supplementary material, which is available to authorized users.

A nonrandomized trial of vitamin D supplementation for Barrett's esophagus

Background

Vitamin D deficiency may increase esophageal cancer risk. Vitamin D affects genes regulating proliferation, apoptosis, and differentiation and induces the tumor suppressor 15-hydroxyprostaglandin dehydrogenase (PGDH) in other cancers. This nonrandomized interventional study assessed effects of vitamin D supplementation in Barrett’s esophagus (BE). We hypothesized that vitamin D supplementation may have beneficial effects on gene expression including 15-PGDH in BE.

Methods

BE subjects with low grade or no dysplasia received vitamin D₃ (cholecalciferol) 50,000 international units weekly plus a proton pump inhibitor for 12 weeks. Esophageal biopsies from normal plus metaplastic BE epithelium and blood samples were obtained before and after vitamin D supplementation. Serum 25-hydroxyvitamin D was measured to characterize vitamin D status. Esophageal gene expression was assessed using microarrays.

Results

18 study subjects were evaluated. The baseline mean serum 25-hydroxyvitamin D level was 27 ng/mL (normal ≥30 ng/mL). After vitamin D supplementation, 25-hydroxyvitamin D levels rose significantly (median increase of 31.6 ng/mL, p<0.001). There were no significant changes in gene expression from esophageal squamous or Barrett’s epithelium including 15-PGDH after supplementation.

Conclusion

BE subjects were vitamin D insufficient. Despite improved vitamin D status with supplementation, no significant alterations in gene expression profiles were noted. If vitamin D supplementation benefits BE, a longer duration or higher dose of supplementation may be needed.

Erratum to: Global DNA methylation patterns in Barrett's esophagus, dysplastic Barrett's, and esophageal adenocarcinoma are associated with BMI, gender, and tobacco use

[This corrects the article DOI: 10.1186/s13148-016-0273-7.].

Association Between Germline Mutation in VSIG10L and Familial Barrett Neoplasia

Importance

Esophageal adenocarcinoma and its precursor lesion Barrett esophagus have seen a dramatic increase in incidence over the past 4 decades yet marked genetic heterogeneity of this disease has precluded advances in understanding its pathogenesis and improving treatment.

Objective

To identify novel disease susceptibility variants in a familial syndrome of esophageal adenocarcinoma and Barrett esophagus, termed familial Barrett esophagus, by using high-throughput sequencing in affected individuals from a large, multigenerational family.

Design, Setting, and Participants

We performed whole exome sequencing (WES) from peripheral lymphocyte DNA on 4 distant relatives from our multiplex, multigenerational familial Barrett esophagus family to identify candidate disease susceptibility variants. Gene variants were filtered, verified, and segregation analysis performed to identify a single candidate variant. Gene expression analysis was done with both quantitative real-time polymerase chain reaction and in situ RNA hybridization. A 3-dimensional organotypic cell culture model of esophageal maturation was utilized to determine the phenotypic effects of our gene variant. We used electron microscopy on esophageal mucosa from an affected family member carrying the gene variant to assess ultrastructural changes.

Main Outcomes and Measures

Identification of a novel, germline disease susceptibility variant in a previously uncharacterized gene.

Results

A multiplex, multigenerational family with 14 members affected (3 members with esophageal adenocarcinoma and 11 with Barrett esophagus) was identified, and whole-exome sequencing identified a germline mutation (S631G) at a highly conserved serine residue in the uncharacterized gene VSIG10L that segregated in affected members. Transfection of S631G variant into a 3-dimensional organotypic culture model of normal esophageal squamous cells dramatically inhibited epithelial maturation compared with the wild-type. VSIG10L exhibited high expression in normal squamous esophagus with marked loss of expression in Barrett-associated lesions. Electron microscopy of squamous esophageal mucosa harboring the S631G variant revealed dilated intercellular spaces and reduced desmosomes.

Conclusions and Relevance

This study presents VSIG10L as a candidate familial Barrett esophagus susceptibility gene, with a putative role in maintaining normal esophageal homeostasis. Further research assessing VSIG10L function may reveal pathways important for esophageal maturation and the pathogenesis of Barrett esophagus and esophageal adenocarcinoma.

Global DNA methylation patterns in Barrett's esophagus, dysplastic Barrett's, and esophageal adenocarcinoma are associated with BMI, gender, and tobacco use

BACKGROUND

The risk of developing Barrett's esophagus (BE) and/or esophageal adenocarcinoma (EAC) is associated with specific demographic and behavioral factors, including gender, obesity/elevated body mass index (BMI), and tobacco use. Alterations in DNA methylation, an epigenetic modification that can affect gene expression and that can be influenced by environmental factors, is frequently present in both BE and EAC and is believed to play a role in the formation of BE and its progression to EAC. It is currently unknown whether obesity or tobacco smoking influences the risk of developing BE/EAC via the induction of alterations in DNA methylation. To investigate this possibility, we assessed the genome-wide methylation status of 81 esophageal tissues, including BE, dysplastic BE, and EAC epithelia using HumanMethylation450 BeadChips (Illumina).

RESULTS

We found numerous differentially methylated loci in the esophagus tissues when comparing males to females, obese to lean individuals, and smokers to nonsmokers. Differences in DNA methylation between these groups were seen in a variety of functional genomic regions and both within and outside of CpG islands. Several cancer-related pathways were found to have differentially methylated genes between these comparison groups.

CONCLUSIONS

Our findings suggest obesity and tobacco smoking may influence DNA methylation in the esophagus and raise the possibility that these risk factors affect the development of BE, dysplastic BE, and EAC through influencing the epigenetic status of specific loci that have a biologically plausible role in cancer formation.

Inverse Association Between Gluteofemoral Obesity and Risk of Barrett's Esophagus in a Pooled Analysis

BACKGROUND & AIMS

Gluteofemoral obesity (determined by measurement of subcutaneous fat in the hip and thigh regions) could reduce risks of cardiovascular and diabetic disorders associated with abdominal obesity. We evaluated whether gluteofemoral obesity also reduces the risk of Barrett's esophagus (BE), a premalignant lesion associated with abdominal obesity.

METHODS

We collected data from non-Hispanic white participants in 8 studies in the Barrett's and Esophageal Adenocarcinoma Consortium. We compared measures of hip circumference (as a proxy for gluteofemoral obesity) from cases of BE (n = 1559) separately with 2 control groups: 2557 population-based controls and 2064 individuals with gastroesophageal reflux disease (GERD controls). Study-specific odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using individual participant data and multivariable logistic regression and combined using a random-effects meta-analysis.

RESULTS

We found an inverse relationship between hip circumference and BE (OR per 5-cm increase, 0.88; 95% CI, 0.81-0.96), compared with population-based controls in a multivariable model that included waist circumference. This association was not observed in models that did not include waist circumference. Similar results were observed in analyses stratified by frequency of GERD symptoms. The inverse association with hip circumference was statistically significant only among men (vs population-based controls: OR, 0.85; 95% CI, 0.76-0.96 for men; OR, 0.93; 95% CI, 0.74-1.16 for women). For men, within each category of waist circumference, a larger hip circumference was associated with a decreased risk of BE. Increasing waist circumference was associated with an increased risk of BE in the mutually adjusted population-based and GERD control models.

CONCLUSIONS

Although abdominal obesity is associated with an increased risk of BE, there is an inverse association between gluteofemoral obesity and BE, particularly among men.

RNA Sequencing Identifies Transcriptionally Viable Gene Fusions in Esophageal Adenocarcinomas

Esophageal adenocarcinoma is a deadly cancer with increasing incidence in the United States, but mechanisms underlying pathogenesis are still mostly elusive. In addressing this question, we assessed gene fusion landscapes by comprehensive RNA sequencing (RNAseq) of 55 pretreatment esophageal adenocarcinoma and 49 nonmalignant biopsy tissues from patients undergoing endoscopy for Barrett's esophagus. In this cohort, we identified 21 novel candidate esophageal adenocarcinoma-associated fusions occurring in 3.33% to 11.67% of esophageal adenocarcinomas. Two candidate fusions were selected for validation by PCR and Sanger sequencing in an independent set of pretreatment esophageal adenocarcinoma (N = 115) and nonmalignant (N = 183) biopsy tissues. In particular, we observed RPS6KB1-VMP1 gene fusion as a recurrent event occurring in approximately 10% of esophageal adenocarcinoma cases. Notably, esophageal adenocarcinoma cases harboring RPS6KB1-VMP1 fusions exhibited significantly poorer overall survival as compared with fusion-negative cases. Mechanistic investigations established that the RPS6KB1-VMP1 transcript coded for a fusion protein, which significantly enhanced the growth rate of nondysplastic Barrett's esophagus cells. Compared with the wild-type VMP1 protein, which mediates normal cellular autophagy, RPS6KB1-VMP1 fusion exhibited aberrant subcellular localization and was relatively ineffective in triggering autophagy. Overall, our findings identified RPS6KB1-VMP1 as a genetic fusion that promotes esophageal adenocarcinoma by modulating autophagy-related processes, offering new insights into the molecular pathogenesis of esophageal adenocarcinomas. Cancer Res; 76(19); 5628-33. ©2016 AACR.

Outcomes after endoscopic versus surgical therapy for early esophageal cancers in an older population

BACKGROUND AND AIMS

Endoscopic treatment of early esophageal cancer provides an alternative to esophagectomy, which older patients may not tolerate. Population-based data regarding short-term outcomes and recurrence after endoscopic treatment for esophageal cancer are limited. We compared short-term outcomes, treated recurrence, and survival after endoscopic versus surgical therapy for early esophageal cancers in an older population.

METHODS

We conducted a retrospective cohort study identifying patients aged ≥66 years with Tis or T1a tumors without nodal involvement diagnosed from 1994 to 2011 from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database.

RESULTS

Of 2193 patients, 41% (n = 893) underwent esophagectomy, and 12% (n = 255) underwent endoscopic treatment within 6 months of diagnosis. Those treated endoscopically were older and more likely to have a Charlson comorbidity score ≥2. A composite endpoint, hospitalization and/or adverse events at 60 days, was higher in surgical patients than in the endoscopic treatment group (30% vs 12%; P < .001). In a Cox model stratified by histology, adjusting for other factors, endoscopic treatment was associated with improved 2-year survival (hazard ratio 0.51; 95% CI, 0.36-0.73).

CONCLUSIONS

In this older population, a composite short-term endpoint was worse in the surgical group. Endoscopic treatment was associated with improved survival through 2 years. These results suggest that endoscopic treatment is a reasonable approach for early esophageal cancers in the elderly.

Abstract 2780: Genome-wide methylation analysis reveals methylator subtypes of Barrett's esophagus and esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) arises from Barrett's Esophagus (BE) through a progression sequence driven by the accumulation of epi/genetic alterations. Genetic alterations and aberrantly methylated genes/loci, the best-characterized epigenetic alteration, vary among individual BE and EAC cases. To better understand the molecular heterogeneity in BE/ EAC, we analyzed genome-wide DNA methylation patterns in BE (N = 98), EAC (N = 23), and normal esophagus and stomach (N = 78) collected via Esophagus Translational Research Network (BETRNet) using Human Methylation 450K (HM450K) arrays. We identified methylation-based subtypes using a model-based recursively partitioned mixture model and unsupervised resampling-based hierarchical cluster analysis with the most variable probes based on standard deviation. All analyses were performed in R. Four methylator subtypes were identified in the BE/EAC dataset using our clustering approach: high (HM); intermediate (IM); low (LM); and minimal (MM). The clusters showed widespread methylation differences in CpGs primarily located in CpG islands (72% of 414 total probes). Each methylation subtype showed distinct genetic and clinical features suggesting underlying biological differences (Table 1). HM exhibited methylation patterns reminiscent of a CpG Island Methylator Phenotype (CIMP). Among BE/EAC cases with known TP53 mutation status, the majority of mutants were among HM and IM clusters (15/19, 78.9%), Finally, identification of methylation subtypes in an independent HM450K dataset of EAC samples (N = 89) from the Cancer Genome Atlas validated the existence of the BE/EAC methylation subtypes. In summary, our data suggest genome wide alterations in DNA methylation occur in the BE stage of the BE-to-EAC progression. We also identified four distinct methylation subtypes of BE/EAC, including a CIMP-like HM subtype, and found more TP53 mutants in the HM and IM subtypes, revealing molecular heterogeneity in different methylation subtypes. Table 1.Characteristics of primary BE/EAC dataset and subtypes from cluster analyses.Cluster CharacteristicSubtypesHigh N (%)Intermediate N (%)Low N (%)Minimal N (%)Total N (%)Case CountsTotal31 (26%)44 (36%)28 (23%)18 (23%)121 (100%)BE23 (23%)34 (35%)24 (24%)17 (17%)98 (100%)EAC8 (35%)10 (43%)4 (17%)1 (4%)23 (100%)Demographic VariablesGenderM28 (28%)35 (35%)23 (23%)14 (14%)100 (100%)GenderF3 (14%)9 (43%)5 (24%)4 (19%)21 (100%)Age (mean ± sd)68 ± 1163 ± 1361 ± 1461 ± 1064 ± 13TP53 Mutations***Mutation*6 (32%)9 (47%)4 (21%)0 (0%)19 (100%)WT6 (30%)8 (40%)5 (25%)1 (5%)20 (100%)Unknown1927191782*** Mutation categories included: Frame Shift Deletion; In Frame Insertion; In Frame Deletion; Missense Mutation; Nonsense Mutation; and Splice Site

Citation Format: Ming Yu, Sean Maden, Andrew Kaz, Tai Heinzerling, Rachele O’Leary, Matthew Stachler, Adam Bass, Amitabh Chak, Joseph Willis, Sanford Markowitz, William Grady. Genome-wide methylation analysis reveals methylator subtypes of Barrett's esophagus and esophageal adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2780.

Rates and predictors of progression to esophageal carcinoma in a large population-based Barrett's esophagus cohort

BACKGROUND AND AIMS

Rates of progression to esophageal adenocarcinoma in subjects with Barrett's esophagus (BE) are lower than previously estimated. Identification of predictors of progression will enable risk stratification of BE subjects, potentially making current surveillance programs more efficient. We aimed to assess the potential of demographic and lifestyle factors, obesity, and medications in predicting progression in BE.

METHODS

BE subjects were identified from the General Practice Research Database using validated diagnostic codes. BE subjects developing esophageal cancer (EC) 12 months after their index BE diagnosis were defined as progressors. Time-to-event analysis was used to assess the overall risk of progression to EC. Cox proportional hazards models and time-varying marginal structural models were used to assess predictors of progression.

RESULTS

Included in the analysis were 9660 BE patients. The mean age (SD) of the study subjects was 63 (13.5) years; 62.6% were men. One hundred three subjects (1.1%) progressed to EC. The mean (SD) follow-up since initial diagnosis was 4.8 (3.3) years. The incidence of EC was 2.23 per 1000 person-years of follow-up. Increasing age, male gender, and being overweight (body mass index, 25-29.9) were found to be independent predictors of progression. When time-varying models were used, proton pump inhibitor (PPI) and statin use were protective against progression.

CONCLUSIONS

In this large population-based cohort of patients with BE, increasing age, male gender, and being overweight predicted progression to EC, whereas PPI and statin use were protective against EC development. These factors may aid in developing a risk score to predict the risk of progression and chemopreventive strategies in patients with BE.

A Molecular Clock Infers Heterogeneous Tissue Age Among Patients with Barrett's Esophagus

Biomarkers that drift differentially with age between normal and premalignant tissues, such as Barrett’s esophagus (BE), have the potential to improve the assessment of a patient’s cancer risk by providing quantitative information about how long a patient has lived with the precursor (i.e., dwell time). In the case of BE, which is a metaplastic precursor to esophageal adenocarcinoma (EAC), such biomarkers would be particularly useful because EAC risk may change with BE dwell time and it is generally not known how long a patient has lived with BE when a patient is first diagnosed with this condition. In this study we first describe a statistical analysis of DNA methylation data (both cross-sectional and longitudinal) derived from tissue samples from 50 BE patients to identify and validate a set of 67 CpG dinucleotides in 51 CpG islands that undergo age-related methylomic drift. Next, we describe how this information can be used to estimate a patient’s BE dwell time. We introduce a Bayesian model that incorporates longitudinal methylomic drift rates, patient age, and methylation data from individually paired BE and normal squamous tissue samples to estimate patient-specific BE onset times. Our application of the model to 30 sporadic BE patients’ methylomic profiles first exposes a wide heterogeneity in patient-specific BE onset times. Furthermore, independent application of this method to a cohort of 22 familial BE (FBE) patients reveals significantly earlier mean BE onset times. Our analysis supports the conjecture that differential methylomic drift occurs in BE (relative to normal squamous tissue) and hence allows quantitative estimation of the time that a BE patient has lived with BE.

Barrett’s Esophagus (BE) is a metaplastic precursor to esophageal adenocarcinoma (EAC). When a patient is diagnosed with BE, it is generally not known how long he/she has had this condition because BE is asymptomatic. While the question of how long a premalignant tissue or lesion has been resident in an organ (dwell time) may not be of importance for cases where curative interventions are readily available (such as adenomas in the colon), for BE, curative interventions are either costly or carry patient risks. Knowledge of a precursor’s dwell time may therefore be advantageous in determining the cancer risk due to the stepwise accumulation of critical mutations in the precursor. In this study, we create a molecular clock model that infers patient-specific BE onsets from DNA methylation data. We show that there is considerable variation in the predicted BE onset times which translates, using mathematical modeling of EAC, into large variation in individual EAC risks. We make the case that, notwithstanding other known risk factors such as chronological age, gender, reflux status, etc., knowledge of biological tissue age can provide valuable patient-specific risk information when a patient is first diagnosed with BE.

Predicting Barrett's Esophagus in Families: An Esophagus Translational Research Network (BETRNet) Model Fitting Clinical Data to a Familial Paradigm

BACKGROUND

Barrett's esophagus is often asymptomatic and only a small portion of Barrett's esophagus patients are currently diagnosed and under surveillance. Therefore, it is important to develop risk prediction models to identify high-risk individuals with Barrett's esophagus. Familial aggregation of Barrett's esophagus and esophageal adenocarcinoma, and the increased risk of esophageal adenocarcinoma for individuals with a family history, raise the necessity of including genetic factors in the prediction model. Methods to determine risk prediction models using both risk covariates and ascertained family data are not well developed.

METHODS

We developed a Barrett's Esophagus Translational Research Network (BETRNet) risk prediction model from 787 singly ascertained Barrett's esophagus pedigrees and 92 multiplex Barrett's esophagus pedigrees, fitting a multivariate logistic model that incorporates family history and clinical risk factors. The eight risk factors, age, sex, education level, parental status, smoking, heartburn frequency, regurgitation frequency, and use of acid suppressant, were included in the model. The prediction accuracy was evaluated on the training dataset and an independent validation dataset of 643 multiplex Barrett's esophagus pedigrees.

RESULTS

Our results indicate family information helps to predict Barrett's esophagus risk, and predicting in families improves both prediction calibration and discrimination accuracy.

CONCLUSIONS

Our model can predict Barrett's esophagus risk for anyone with family members known to have, or not have, had Barrett's esophagus. It can predict risk for unrelated individuals without knowing any relatives' information.

IMPACT

Our prediction model will shed light on effectively identifying high-risk individuals for Barrett's esophagus screening and surveillance, consequently allowing intervention at an early stage, and reducing mortality from esophageal adenocarcinoma. Cancer Epidemiol Biomarkers Prev; 25(5); 727-35. ©2016 AACR.

Linkage and related analyses of Barrett's esophagus and its associated adenocarcinomas

Background

Familial aggregation and segregation analysis studies have provided evidence of a genetic basis for esophageal adenocarcinoma (EAC) and its premalignant precursor, Barrett's esophagus (BE). We aim to demonstrate the utility of linkage analysis to identify the genomic regions that might contain the genetic variants that predispose individuals to this complex trait (BE and EAC).

Methods

We genotyped 144 individuals in 42 multiplex pedigrees chosen from 1000 singly ascertained BE/EAC pedigrees, and performed both model‐based and model‐free linkage analyses, using S.A.G.E. and other software. Segregation models were fitted, from the data on both the 42 pedigrees and the 1000 pedigrees, to determine parameters for performing model‐based linkage analysis. Model‐based and model‐free linkage analyses were conducted in two sets of pedigrees: the 42 pedigrees and a subset of 18 pedigrees with female affected members that are expected to be more genetically homogeneous. Genome‐wide associations were also tested in these families.

Results

Linkage analyses on the 42 pedigrees identified several regions consistently suggestive of linkage by different linkage analysis methods on chromosomes 2q31, 12q23, and 4p14. A linkage on 15q26 is the only consistent linkage region identified in the 18 female‐affected pedigrees, in which the linkage signal is higher than in the 42 pedigrees. Other tentative linkage signals are also reported.

Conclusion

Our linkage study of BE/EAC pedigrees identified linkage regions on chromosomes 2, 4, 12, and 15, with some reported associations located within our linkage peaks. Our linkage results can help prioritize association tests to delineate the genetic determinants underlying susceptibility to BE and EAC.

Rectal indomethacin alone versus indomethacin and prophylactic pancreatic stent placement for preventing pancreatitis after ERCP: study protocol for a randomized controlled trial

Background

The combination of prophylactic pancreatic stent placement (PSP) – a temporary plastic stent placed in the pancreatic duct – and rectal non-steroidal anti-inflammatory drugs (NSAIDs) is recommended for preventing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk cases. Preliminary data, however, suggest that PSP may be unnecessary if rectal NSAIDs are administered. Given the costs and potential risks of PSP, we aim to determine whether rectal indomethacin obviates the need for pancreatic stent placement in patients undergoing high-risk ERCP.

Methods/Design

The SVI (Stent vs. Indomethacin) trial is a comparative effectiveness, multicenter, randomized, double-blind, non-inferiority study of rectal indomethacin alone versus the combination of rectal indomethacin and PSP for preventing PEP in high-risk cases. One thousand four hundred and thirty subjects undergoing high-risk ERCP, in whom PSP is planned solely for PEP prevention, will be randomized to indomethacin alone or combination therapy. Those who are aware of study group assignment, including the endoscopist, will not be involved in the post-procedure care of the patient for at least 48 hours. Subjects will be assessed for PEP and its severity by a panel of independent and blinded adjudicators. Indomethacin alone will be declared non-inferior to combination therapy if the two-sided 95 % upper confidence bound of the treatment difference is less than 5 % between the two groups. Biological specimens will be obtained from trial participants and centrally banked.

Discussion

The SVI trial is designed to determine whether PSP remains necessary in the era of NSAIDs pharmacoprevention. The associated bio-repository will establish the groundwork for important scientific breakthrough.

Trial registration

NCT02476279, registered June 2015.

Association of Serum Levels of Adipokines and Insulin With Risk of Barrett's Esophagus: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Metabolically active visceral fat may be associated with esophageal inflammation, metaplasia, and neoplasia. We performed a meta-analysis to evaluate the association of serum adipokines and insulin with Barrett's esophagus (BE).

METHODS

We performed a systematic search of multiple electronic databases, through April 2015, to identify all studies reporting associations between leptin, adiponectin, insulin, insulin resistance, and risk of BE in adults. Comparing the highest study-specific category with the reference category for each hormone, we estimated the summary adjusted odds ratio (aOR) and 95% confidence intervals (CI), using a random effects model.

RESULTS

We identified 9 observational studies (10 independent cohorts; 1432 patients with BE total, and 3550 control subjects). Meta-analysis revealed that high serum level of leptin was associated with 2-fold higher risk of BE (BE cases vs population control subjects in 5 studies: aOR, 2.23; 95% CI, 1.31-3.78; I(2), 59%). Total serum level of adiponectin was not associated with BE (BE cases vs population control subjects in 5 studies: aOR, 0.79; 95% CI, 0.46-1.34; I(2), 65%), although 1 study observed decreased risk of BE with increased level of low-molecular-weight adiponectin. High serum level of insulin was associated with increased risk of BE (BE cases vs population control subjects in 3 studies: aOR, 1.74; 95% CI, 1.14-2.65; I(2), 0), whereas insulin resistance was not associated with increased risk of BE (BE cases vs gastroesophageal reflux disease control subjects in 2 studies: aOR, 0.98; 95% CI, 0.42-2.30; I(2), 64%).

CONCLUSIONS

Increased serum levels of leptin and insulin are associated with increased risk of BE, compared with population control subjects. In contrast, increased total serum levels of adiponectin and insulin do not seem to modify BE risk. Well-designed longitudinal studies of incident BE are needed to clarify existing associations of serum adipokines and insulin with BE.