Wytske Westra

High cancer risk and increased mortality in patients with Peutz–Jeghers syndrome

We thank Dr Vande Casteele and colleagues for their interest in our work and commend them for their interesting case. 2 As written in our manuscript, we have had several, and in some cases serial, measurements of infliximab and antidrug antibody (ADA) levels in the patients reported. However, we limited the results to the last sample available before loss of response occurred to better meet the aim of the study, which was to investigate the immunogenic fragment of infliximab and its possible diagnostic role in patients having inflammatory bowel disease with loss of response. We absolutely agree that serial measurements may allow early detection of pharmacodynamic changes which possibly herald the later onset of clinical events such as loss of response or infusion reactions. The case report by Dr Vande Casteele is an interesting example of this principle and is also notable for demonstrating the variable time course of ADA formation which was detected for adalimumab at one point and later disappeared. However, we would caution that much more evidence is needed regarding the predictive power, the time course and the cost-effectiveness of routine serial measurements of the drug and ADA levels before this approach can be advocated as a clinical recommendation in all patients treated with anti-tumour necrosis factor (anti-TNF). We would also beg to differ with the authors’ assertion that ‘the lack of infliximab and adalimumab blood levels contributed to the formation of antibodies to the drug’. In fact, most data indicate that it is the formation of antibodies and subsequent immune complexes with the drug that hasten drug clearance, thereby leading to absent drug levels in the blood. Finally, there is no mention of concomitant immunomodulators used in the particular patient, if any. Data from the authors’ group previously demonstrated the efficacy of concomitant immunomodulators to reduce immunogenicity, at least in episodically treated patients. Moreover, we have shown that prolonged administration of 6-mercaptopurine mediated the deletion of antigen-specific T helper cells, despite repeated antigen exposures. On a conceptual level, this could suggest that addition of thiopurines may incrementally eliminate the drug-specific memory cells, reduce the titres of ADAs and thereafter restore clinical response in patients who already formed antibodies to anti-TNFs. However, it remains to be proven in clinical trials whether these mechanistic observations in murine experiments could indeed translate into an efficacious management approach for immunogenic loss of response to anti-TNFs.

Derivation of genetic biomarkers for cancer risk stratification in Barrett’s oesophagus: a prospective cohort study

Objective The risk of developing adenocarcinoma in non-dysplastic Barretts oesophagus is low and difficult to predict. Accurate tools for risk stratification are needed to increase the efficiency of surveillance. We aimed to develop a prediction model for progression using clinical variables and genetic markers. Methods In a prospective cohort of patients with non-dysplastic Barretts oesophagus, we evaluated six molecular markers: p16, p53, Her-2/neu, 20q, MYC and aneusomy by DNA fluorescence in situ hybridisation on brush cytology specimens. Primary study outcomes were the development of high-grade dysplasia or oesophageal adenocarcinoma. The most predictive clinical variables and markers were determined using Cox proportional-hazards models, receiver operating characteristic curves and a leave-one-out analysis. Results A total of 428 patients participated (345 men; median age 60 years) with a cumulative follow-up of 2019 patient-years (median 45 months per patient). Of these patients, 22 progressed; nine developed high-grade dysplasia and 13 oesophageal adenocarcinoma. The clinical variables, age and circumferential Barretts length, and the markers, p16 loss, MYC gain and aneusomy, were significantly associated with progression on univariate analysis. We defined an ‘Abnormal Marker Count’ that counted abnormalities in p16, MYC and aneusomy, which significantly improved risk prediction beyond using just age and Barretts length. In multivariate analysis, these three factors identified a high-risk group with an 8.7-fold (95% CI 2.6 to 29.8) increased HR when compared with the low-risk group, with an area under the curve of 0.76 (95% CI 0.66 to 0.86). Conclusions A prediction model based on age, Barretts length and the markers p16, MYC and aneusomy determines progression risk in non-dysplastic Barretts oesophagus.

Molecular mechanisms of Barrett's esophagus and adenocarcinoma.

The following on molecular mechanisms of Barretts esophagus and adenocarcinoma contains commentaries on the mechanism of bile and gastric acid induced damage; the roles of BMP‐4 and CDX‐2 in the development of intestinal metaplasia; the transcription factors driving intestinalization in Barretts esophagus; the contribution of bone marrow to metaplasia and adenocarcinoma; activation and inactivation of transcription factors; and a novel study design targeting molecular pathways in Barretts esophagus.

Su1181 A Diagnostic DNA FISH Biomarker Assay Identifies HGD or EAC in Barrett Esophagus

examine the effect of acid on Wnt/β-catenin signaling activation and on regulating the expression of Dickkopf1 (DKK1), an inhibitor of the Wnt. Methods: Normal esophageal squamous cells lines (EPC1-hTERT, EPC2-hTERT), a non-dysplastic Barretts esophageal cell line (CP-A) and an esophageal adenocarcinoma cell line (OE33) were exposed to acidic media (pH 4.0) in a pulsive manner. Human esophageal mucosal biopsies in triplicate from healthy (n=1), NERD (n=1), GERD (n=1) and Barretts (n=1) patients were obtained and cultured in acidic (pH 4.0) or non acidic media. Localization and levels of β-catenin were determined by Immunofluorescence staining and Western blot. Wnt-activity was assessed by Luciferase assay following transfection with β-catenin-LEF/TCF-sensitive (TOP) or βcatenin-LEF/TCF insensitive (FOP) reporter vector. Immunofluorescence was used for βcatenin and E-Cadherin co-localization. DKK1 and β-catenin gene expression was resolved by qRT-PCR. DKK1 secretion in cells culture media and organ culture media was quantified by ELISA assay.Results: Acid destabilized E-cadherin/β-catenin complex in cell-cell junctions and resulted in β-catenin translocation to nucleus. Wnt-activity correlated with nuclear translocation of β-catenin. Cytosolic shuttling of β-catenin occurred in a rapid and transient manner after acid withdrawal. Chronic pulsed acid exposure increased DKK1 expression in normal squamous cells but not in metaplastic columnar cells. DKK1 overexpression correlated with a significant degradation of β-catenin. Mucosal biopsies from patients with NERD/ GERD secreted significantly higher levels of Dkk1 than healthy and metaplastic mucosa biopsies. Conclusions: These findings suggest that acid reflux induces the activation of Wnt-signaling pathway and that the overexpression of DKK1 is the long term response in the normal squamous esophageal tissue but not in the Barretts esophagus. These findings also suggest a homeostatic role for DKK1 in GERD and its dysfunction to be a potential mechanism for progression to Barretts metaplasia.

Smokeless Tobacco and Cigar and/or Pipe Are Risk Factors for Barrett Esophagus in Male Patients With Gastroesophageal Reflux Disease

Objective: To investigate the effect of smokeless tobacco (ST), cigar and/or pipe smoking (CP) on the development of Barrett esophagus (BE) in white male patients with gastroesophageal reflux disease (GERD). Patients and Methods: A total of 1015 records of white male adults with BE (cases; n=508) or GERD (controls, n=507) were reviewed for lifestyle factors. Logistic regression analyses were performed after adjusting for lifestyle factors to assess the effects of ST and CP on the risk of developing BE. Differences between patients with BE and those with GERD were compared using chi‐square and t tests. Results: Patients with BE were significantly older than patients with GERD (mean age, 66±12 years for patients with BE and 55±15 years for patients with GERD; P<.001). The odds of developing BE in patients who used CS were 1.7 times higher than that in patients who never smoked cigarettes (odds ratio [OR], 1.7; 95% CI, 1.3‐2.2). It was observed that when CS use was combined with either ST or CP use, the odds of having BE significantly increased (OR, 2.5; 95% CI, 1.2‐5.2; P=.01 and OR, 1.9; 95% CI, 1.03‐3.58; P=.04) in comparison to CS alone. There were no significant differences in body mass index and alcohol consumption between BE and GERD groups. Conclusion: This study suggests that there is indeed an association between CS and BE. We believe that this is the first time that ST and CP were associated with an even higher odds of developing BE. Further studies are needed to investigate whether the use of ST and CP is also associated with an increased risk of developing BE‐associated adenocarcinoma.

Sa1835 Tobacco Chewing and Smoking Are Risk Factors for Barrett's Esophagus in Caucasian GERD Patients

G A A b st ra ct s 3 intensity levels (walking, moderate intensity and vigorous intensity) during the past 7 days. We categorized level of physical activity by low, moderate, or high using IPAQ definitions. We also estimated metabolic equivalent minutes per week (MET-min/wk) by weighting the reported minutes/week within each activity category by a MET energy expenditure estimate for each category of activity. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) using multivariable logistic regression models adjusting for age, sex, race, GERD symptoms, H. pylori, BMI and high waist-to-hip ratio. Results: There were 323 cases with BE and 1849 controls (1347 from endoscopy and 502 from the primary care clinic) (Table 1). Most (68.8%) patients were in the lowest category of physical activity, 13.5% had moderate activity and 11.2% had high activity (6.5% were missing). BE cases were more likely to be in the high category physical activity category than controls (13.6% vs. 10.8% p=0.08). The overall average MET-min/week for walking were 909 for BE cases vs. 561 in controls (p=0.16); with similar findings for those with moderate activity (1094 METmin/week for BE cases vs. 755 for controls, p=0.175), and for vigorous activity (783.8 METmin/week for BE cases vs. 826.2 for controls, p=0.927). In multivariable logistic regression, physical activity was not significantly associated with BE (OR for high vs. low physical activity: 1.19 (95%CI: 0.8-1.73). In fact, BE patients were more likely to have high level of physical activity than PCP controls (OR: 2.1; 95% CI: 1.17-3.6). Conclusions: Recent amount and intensity of physical activity does not seem to be associated with significant changes in the risk of BE. Studies are required examine long term effects of physical activity.

T1883 Detection of High-Grade Dysplasia and Esophageal Adenocarcinoma Using Endoscopic Mucosal Resection in Combination with Fluorescence in Situ Hybridization

Detection of High-Grade Dysplasia and Esophageal Adenocarcinoma Using Endoscopic Mucosal Resection in Combination with Fluorescence in Situ Hybridization Wytske Westra, Ganapathy A. Prasad, Kevin C. Halling, Shannon M. Brankley, Emily Barr Fritcher, Trynda N. Oberg, Jesse S. Voss, Michael B. Campion, Navtej Buttar, LouisMichel Wong Kee Song, Lori S. Lutzke, Kelly T. Dunagan, Lynn S. Borkenhagen, Agnieszka M. Rygiel, Kausilia K. Krishnadath, Kenneth K. Wang