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1.  Positive correlation between endoscopist radiofrequency ablation volume and response rates in Barrett’s esophagus 
Gastrointestinal endoscopy  2014;80(1):71-77.
Radiofrequency ablation (RFA) has become an accepted form of endoscopic treatment for Barrett’s esophagus (BE), yet reported response rates are variable. There are no accepted quality measures for performing RFA, and provider-level characteristics may influence RFA outcomes.
To determine whether endoscopist RFA volume is associated with rates of complete remission of intestinal metaplasia (CRIM) after RFA in patients with BE.
Retrospective analysis of longitudinal data.
Three tertiary-care medical centers.
Patients with BE treated with RFA.
Main Outcome Measurements
For each endoscopist, we recorded RFA volume, defined as the number of unique patients treated as well as corresponding CRIM rates. We calculated a Spearman correlation coefficient relating these 2 measures.
We identified 417 patients with BE treated with RFA who had at least 1 post-RFA endoscopy with biopsies. A total of 73% of the cases had pretreatment histology of high-grade dysplasia or adenocarcinoma. The procedures were performed by 7 endoscopists, who had a median RFA volume of 62 patients (range 20–188). The overall CRIM rate was 75.3% (provider range 62%–88%). The correlation between endoscopist RFA volume and CRIM rate was strong and significant (rho = 0.85; P = .014). In multivariable analysis, higher RFA volume was significantly associated with CRIM (P for trend .04).
Referral setting may limit generalizability. Limited number of endoscopists analyzed.
Endoscopist RFA volume correlates with rates of successful BE eradication. Further studies are required to confirm these findings and to determine whether RFA volume is a valid predictor of treatment outcomes in BE.
PMCID: PMC4317349  PMID: 24565071
2.  Modeling inflammation and oxidative stress in gastrointestinal disease development using novel organotypic culture systems 
Stem Cell Research & Therapy  2013;4(Suppl 1):S5.
Gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), graft-versus-host disease (GVHD), and inflammatory bowel diseases such as ulcerative colitis and Crohn's disease are common human gastrointestinal diseases that share inflammation as a key driver for their development. A general outcome resulting from these chronic inflammatory conditions is increased oxidative stress. Oxidative stress is caused by the generation of reactive oxygen and nitrogen species that are part of the normal inflammatory response, but are also capable of damaging cellular DNA, protein, and organelles. Damage to DNA can include DNA strand breaks, point mutations due to DNA adducts, as well as alterations in methylation patterns leading to activation of oncogenes or inactivation of tumor suppressors. There are a number of significant long-term consequences associated with chronic oxidative stress, most notably cancer. Infiltrating immune cells and stromal components of tissue including fibroblasts contribute to dynamic changes occurring in tissue related to disease development. Immune cells can potentiate oxidative stress, and fibroblasts have the capacity to contribute to advanced growth and proliferation of the epithelium and any resultant cancers. Disease models for GERD, BE, GVHD, and ulcerative colitis based on three-dimensional human cell and tissue culture systems that recapitulate in vivo growth and differentiation in inflammatory-associated microphysiological environments would enhance our understanding of disease progression and improve our ability to test for disease-prevention strategies. The development of physiologically relevant, human cell-based culture systems is therefore a major focus of our research. These novel models will be of enormous value, allowing us to test hypotheses and advance our understanding of these disorders, and will have a translational impact allowing us to more rapidly develop therapeutic and chemopreventive agents. In summary, this work to develop advanced human cell-based models of inflammatory conditions will greatly improve our ability to study, prevent, and treat GERD, BE, GVHD, and inflammatory bowel disease. The work will also foster the development of novel therapeutic and preventive strategies that will improve patient care for these important clinical conditions.
PMCID: PMC3983655  PMID: 24564965
inflammation; oxidative stress; DNA damage; gastrointestinal disease; gastroesophageal reflux disease; Barrett's esophagus; graft-versus-host disease; inflammatory bowel disease; human three-dimensional organotypic model systems
4.  Recurrence of Esophageal Intestinal Metaplasia After Endoscopic Mucosal Resection and Radiofrequency Ablation of Barrett’s Esophagus: Results From a US Multicenter Consortium Recurrence of Barrett’s Esophagus after EMR and RFA 
Gastroenterology  2013;145(1):79-86.e1.
Radiofrequency ablation (RFA) is an established treatment for dysplastic Barrett’s esophagus (BE). Although short-term endpoints of ablation have been ascertained, there have been concerns about recurrence of intestinal metaplasia (IM) after ablation. We aimed to estimate the incidence and identify factors that predicted the recurrence of IM after successful RFA.
We analyzed data from 592 patients with BE treated with RFA from 2003 through 2011 at 3 tertiary referral centers. Complete remission of intestinal metaplasia (CRIM) was defined as eradication of IM (in esophageal and gastro esophageal junction biopsies), documented by 2 consecutive endoscopies. Recurrence was defined as presence of IM or dysplasia after CRIM in surveillance biopsies. Two experienced gastrointestinal pathologists confirmed pathology findings.
Based on histology analysis, before RFA, 71% of patients had high-grade dysplasia or esophageal adenocarcinoma, 15% had low-grade dysplasia, and 14% had non-dysplastic BE. Of patients treated, 448 (76%) were assessed following RFA. 55% of patients underwent endoscopic mucosal resection before RFA. The median time to CRIM was 22 months, with 56% of patients in CRIM by 24 months. Increasing age and length of BE segment were associated with a longer times to CRIM. Twenty-four months after CRIM, the incidence of recurrence was 33%; 22% of all recurrences observed were dysplastic BE. There were no demographic or endoscopic factors associated with recurrence. Complications developed in 6.5% of subjects treated with RFA; strictures were the most common complication.
Of patients with BE treated by RFA, 56% are in complete remission after 24 months. However, 33% of these patients have disease recurrence within the next 2 years. Most recurrences were non-dysplastic and endoscopically manageable, but continued surveillance after RFA is essential.
PMCID: PMC3696438  PMID: 23499759
esophageal cancer; prevention; endoscopic therapy; EAC
5.  TSLP-elicited basophil responses can mediate the pathogenesis of eosinophilic esophagitis 
Nature medicine  2013;19(8):1005-1013.
Eosinophilic esophagitis (EoE) is a food allergy-associated inflammatory disease characterized by esophageal eosinophilia. EoE has become increasingly common, but current management strategies are nonspecific. Thus, there is an urgent need to identify specific immunological pathways that could be targeted to treat this disease. EoE is associated with polymorphisms in the gene that encodes thymic stromal lymphopoietin (TSLP), a cytokine that promotes allergic inflammation, but how TSLP might contribute to EoE disease pathogenesis remains unknown. Here, we describe a new mouse model of EoE-like disease that developed independently of IgE but was dependent on TSLP-elicited basophils. Therapeutic TSLP neutralization or basophil depletion also ameliorated established EoE-like disease. Critically, in human subjects with EoE, we observed elevated TSLP levels and exaggerated basophil responses in esophageal biopsies, and a gain-of-function TSLP polymorphism was associated with increased basophil responses. Together, these data suggest that the TSLP-basophil axis could be therapeutically targeted to treat EoE.
PMCID: PMC3951204  PMID: 23872715
6.  Esomeprazole and 325 mg/d Aspirin Reduce Tissue Concentrations of Prostaglandin E2 in Patients with Barrett’s Esophagus 
Gastroenterology  2012;143(4):917-926.e1.
Background & Aims
Proton pump inhibitors (PPIs) and nonsteroidal anti-inflammatory drugs might prevent esophageal adenocarcinoma in patients with Barrett’s esophagus (BE), but there are limited data from clinical trials to support this concept. We conducted a randomized, double-blind, placebo-controlled phase II trial to assess the effects of the combination of aspirin (3 different doses) and esomeprazole on tissue concentrations of prostaglandin E2 (PGE2) in patients with BE with no dysplasia or low-grade dysplasia.
Participants were recruited through the multi-center Cancer Prevention Network and randomly assigned to groups that were given esomeprazole (40 mg, twice daily) in combination with an aspirin placebo (once daily) (Arm A; n=42), with 81 mg aspirin (once daily) (Arm B; n=63), or with 325 mg aspirin (once daily) (Arm C; n=63) for 28 days. We collected esophageal biopsies before and after the intervention period, to determine the absolute change in mean concentrations of PGE2 (the primary endpoint).
Based on data from 114 patients, baseline characteristics were similar among groups. The absolute mean tissue concentrations of PGE2 was reduced by 67.6±229.68 pg/mL in Arm A, was reduced by 123.9±284.0 pg/mL in Arm B (P=.10 vs Arm A), and was reduced by 174.9 ±263.62 pg/mL in Arm C (P=.02 vs Arm A).
In combination with esomeprazole, short-term administration of higher doses of aspirin, but not lower doses or no aspirin, significantly reduced tissue concentrations of PGE2 patients with BE with either no dysplasia or low-grade dysplasia. These data support further evaluation of higher doses of aspirin and esomeprazole to prevent esophageal adenocarcinoma in these patients.
PMCID: PMC3458136  PMID: 22796132
esophageal cancer; NSAIDs; inflammation; esophagus
8.  Association of insulin and insulin-like growth factors with Barrett’s oesophagus 
Gut  2011;61(5):665-672.
It is postulated that high serum levels of insulin and insulin growth factor 1 (IGF-1) mediate obesity-associated carcinogenesis. The relationship of insulin, IGF-1 and IGF binding proteins (IGFBP) with Barrett’s oesophagus (BO) has not been well examined.
Serum levels of insulin and IGFBPs in patients with BO were compared with two separate control groups: subjects with gastro-oesophageal reflux disease (GORD) and screening colonoscopy controls. Fasting insulin, IGF-1 and IGFBPs were assayed in the serum of BO cases (n = 135), GORD (n = 135) and screening colonoscopy (n = 932) controls recruited prospectively at two academic hospitals. Logistic regression was used to estimate the risk of BO.
Patients in the highest tertile of serum insulin levels had an increased risk of BO compared with colonoscopy controls (adjusted OR 2.02, 95% CI 1.15 to 3.54) but not compared with GORD controls (adjusted OR 1.55, 95% CI 0.76 to 3.15). Serum IGF-1 levels in the highest tertile were associated with an increased risk of BO (adjusted OR 4.05, 95% CI 2.01 to 8.17) compared with the screening colonoscopy control group but were not significantly different from the GORD control group (adjusted OR 0.57, 95% CI 0.27 to 1.17). IGFBP-1 levels in the highest tertile were inversely associated with a risk of BO in comparison with the screening colonoscopy controls (adjusted OR 0.11, 95% CI 0.05 to 0.24) but were not significantly different from the GORD control group (adjusted OR 1.04, 95% CI 0.49 to 2.16). IGFBP-3 levels in the highest tertile were inversely associated with the risk of BO compared with the GORD controls (OR 0.36, 95% CI 0.16 to 0.81) and also when compared with the colonoscopy controls (OR 0.40, 95% CI 0.20 to 0.79).
These results provide support for the hypothesis that the insulin/IGF signalling pathways have a role in the development of BO.
PMCID: PMC3669672  PMID: 21930730
9.  Variation In Age At Cancer Diagnosis In Familial Versus Non-Familial Barrett’s Esophagus 
Genetic influences may be discerned in families that have multiple affected members and may manifest as an earlier age of cancer diagnosis. In this study we determine whether cancers develop at an earlier age in multiplex Familial Barrett’s Esophagus (FBE) kindreds, defined by 3 or more members affected by Barrett’s esophagus (BE) or esophageal adenocarcinoma (EAC).
Information on BE/EAC risk factors and family history was collected from probands at eight tertiary care academic hospitals. Age of cancer diagnosis and other risk factors were compared between non-familial (no affected relatives), duplex (two affected relatives), and multiplex (three or more affected relatives) FBE kindreds.
The study included 830 non-familial, 274 duplex and 41 multiplex FBE kindreds with 274, 133 and 43 EAC and 566, 288 and 103 BE cases, respectively. Multivariable mixed models adjusting for familial correlations showed that multiplex kindreds were associated with a younger age of cancer diagnosis (p = 0.0186). Median age of cancer diagnosis was significantly younger in multiplex compared to duplex and non-familial kindreds (57 vs. 62 vs. 63 yrs, respectively, p = 0.0448). Mean body mass index (BMI) was significantly lower in multiplex kindreds (p = 0.0033) as was smoking (p < 0.0001), and reported regurgitation (p = 0.0014).
Members of multiplex FBE kindreds develop EAC at an earlier age compared to non-familial EAC cases. Multiplex kindreds do not have a higher proportion of common risk factors for EAC, suggesting that this aggregation might be related to a genetic factor.
These findings indicate that efforts to identify susceptibility genes for BE and EAC will need to focus on multiplex kindreds.
PMCID: PMC3275661  PMID: 22178570
Esophageal adenocarcinoma; Barrett’s esophagus; genetics; family history
10.  Durability of Radiofrequency Ablation in Barrett’s Esophagus with Dysplasia 
Gastroenterology  2011;141(2):460-468.
Background & Aims
Radiofrequency ablation (RFA) can eradicate dysplasia and intestinal metaplasia in patients with dysplastic Barrett’s esophagus (BE), and reduce rates of esophageal adenocarcinoma. We assessed long-term rates of eradication, durability of neosquamous epithelium, disease progression, and safety of RFA in patients with dysplastic BE.
We performed a randomized trial of 127 subjects with dysplastic BE; after cross-over subjects were included 119 received RFA. Subjects were followed for a mean time of 3.05 years; the study was extended to 5 years for patients with eradication of intestinal metaplasia at 2 years. Outcomes included eradication of dysplasia or intestinal metaplasia after 2 and 3 years, durability of response, disease progression, and adverse events.
After 2 years, 101/106 patients had complete eradication of all dysplasia (95%) and 99/106 had eradication of intestinal metaplasia (93%). After 2 years, among subjects with initial low-grade dysplasia, all dysplasia was eradicated in 51/52 (98%) and intestinal metaplasia was eradicated in 51/52 (98%); among subjects with initial high-grade dysplasia, all dysplasia was eradicated in 50/54 (93%) and intestinal metaplasia was eradicated in 48/54 (89%). After 3 years, dysplasia was eradicated in 55/56 of subjects (98%) and intestinal metaplasia was eradicated in 51/56 (91%). Kaplan-Meier analysis showed that dysplasia remained eradicated in >85% of patients and intestinal metaplasia in >75%, without maintenance RFA. Serious adverse events occurred in 4/119 subjects (3.4%); the rate of stricture was 7.6%. The rate of esophageal adenocarcinoma was 1/181 pt-yrs (0.55%/pt-yr); there was no cancer-related morbidity or mortality. The annual rate of any neoplastic progression was 1/73 pt-yrs (1.37%/pt-yr).
In subjects with dysplastic BE, RFA therapy has an acceptable safety profile, is durable, and is associated with a low rate of disease progression, for up to 3 years.
PMCID: PMC3152658  PMID: 21679712
esophagus; cancer; prevention; endoscopic therapy
11.  A Segregation Analysis of Barrett’s Esophagus and Associated Adenocarcinomas 
Familial aggregation of esophageal adenocarcinomas, esophagogastric junction adenocarcinomas, and their precursor Barrett’s esophagus has been termed Familial Barrett’s Esophagus (FBE). Numerous studies documenting increased familial risk for these diseases raise the hypothesis that there may be an inherited susceptibility to the development of BE and its associated cancers. In this study, using segregation analysis for a binary trait as implemented in S.A.G.E. 6.0.1, we analyzed data on 881singly ascertained pedigrees in order to determine whether FBE is caused by a common environmental or genetic agent and, if genetic, to identify the mode of inheritance of FBE. The inheritance models were compared by likelihood ratio tests and Akaike’s A Information Criterion. Results indicated that random environmental and/or multifactorial components were insufficient to fully explain the familial nature of FBE, but rather there is segregation of a major type transmitted from one generation to the next (p-value < 10−10). An incompletely dominant inheritance model together with a polygenic component fits the data best. For this dominant model, the estimated penetrance of the dominant allele is 0.1005 (95% confidence interval, CI: 0.0587 to 0.1667) and the sporadic rate is 0.0012 (95% CI: 0.0004 to 0.0042), corresponding to a relative risk of 82.53 (95% CI: 28.70 to 237.35), or odds ratio of 91.63 (95% CI: 32.01 to 262.29). This segregation analysis provides epidemiological evidence in support of one or more rare autosomally inherited dominant susceptibility allele(s) in FBE families, and hence motivates linkage analyses.
PMCID: PMC2838211  PMID: 20200424
familial esophageal adenocarcinomas; complex segregation analysis; dominant major gene inheritance; polygenic component; likelihood; AIC; unified model
12.  Assessment of Familiality, Obesity, and Other Risk Factors for Early Age of Cancer Diagnosis in Adenocarcinomas of the Esophagus and Gastro-esophageal Junction 
Adenocarcinomas of the esophagus and adenocarcinomas of the gastroesophageal junction are postulated to be complex genetic diseases. Combined influences of environmental factors and genetic susceptibility likely influence the age at which these cancers develop. The aim of this study was to determine whether familiality and other recognized risk factors are associated with the development of these cancers at an earlier age.
A structured validated questionnaire was utilized to collect self reported data on gastro-esophageal reflux symptoms, risk factors for Barrett’s esophagus (BE) and family history, including age of cancer diagnosis in affected relatives from probands with BE, adenocarcinoma of the esophagus, or adenocarcinoma of the gastro-esophageal junction, at five tertiary care academic hospitals. Medical records of all relatives reported to be affected were requested from hospitals providing this cancer care to confirm family histories. Familiality of BE/cancer, obesity (defined as body mass index > 30), gastro-esophageal reflux symptoms, and other risk factors were assessed for association with a young age of cancer diagnosis.
A total of 356, 216 non-familial and 140 familial, cancers were studied. The study population consisted of 292 (82%) men and 64 (18%) women. Mean age of cancer diagnosis was no different comparing familial and non-familial cancers, 62.6 yrs vs. 61.9 yrs, p = 0.70. There were also no significant differences in symptoms of gastroesophageal reflux, body mass index, race, gender, and smoking history between familial and non-familial cancers. Mean age of cancer diagnosis was significantly younger comparing those who were obese one year prior to diagnosis with those who were non-obese, mean age 58.99 yrs vs. 63.6 yrs, p = 0.008. Multivariable modeling of age at cancer diagnosis showed that obesity 1 year before diagnosis was associated with a younger age of cancer diagnosis (p=0.005) after adjustment for heartburn and regurgitation duration.
Obesity is associated with the development of esophageal and gastro-esophageal junctional adenocarcinomas at an earlier age. Familial cancers arise at the same age as non-familial cancers and have a similar risk factor profile.
PMCID: PMC2864226  PMID: 19491834
13.  Evidence for DNA Damage Checkpoint Activation in Barrett Esophagus1 
Translational Oncology  2010;3(1):33-42.
Barrett esophagus is an epithelial metaplasia that predisposes to adenocarcinoma. Better markers of cancer risk are urgently needed to identify those patients who are likely to benefit most from emerging methods of endoscopic ablation. Disease progression is associated with genomic DNA changes (segmental gains, losses, or loss of heterozygosity). Although these changes are not easily assayed directly, we hypothesized that the underlying DNA damage should activate a DNA damage response (DDR), detectable by immunohistochemical (IHC) assays of checkpoint proteins and the resulting replicative phase cell cycle delays. Surgical specimens and endoscopic biopsies (N = 28) were subjected to IHC for the cell cycle markers cyclin A and phosphorylated histone H3 (P-H3), the DDR markers γH2AX and phosphorylated ATM/ATR substrates (P-ATM/ATRsub), and the DNA damage-responsive tumor suppressors p16 and p53. Correlations were made with histologic diagnoses. The fractions of cells that stained for cyclin A, P-H3, and γH2AX increased in parallel in dysplastic tissue, consistent with checkpoint-mediated cell cycle delays. Foci of nuclear γH2AX and P-ATM/ATRsub were demonstrated by standard and confocal immunofluorescence. Staining for p16 was more prevalent in early-stage disease with lower staining for γH2AX and P-H3. Staining for p53 was moderately increased in some early-stage disease and strongly increased in some advanced disease, consistent with checkpoint-mediated induction and mutational inactivation of p53, respectively. We suggest that IHC for DDR-associated markers may help stratify risk of disease progression in Barrett.
PMCID: PMC2822452  PMID: 20165693

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