Markowitz, Sanford D.

INTRODUCTION: Preliminary data suggest that an encapsulated balloon (EsoCheck), coupled with a 2 methylated DNA biomarker panel (EsoGuard), detects Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) with high accuracy. The initial assay requires sample freezing upon collection. The purpose of this study was to assess a next-generation EsoCheck sampling device and EsoGuard assay in a much-enlarged multicenter study clinically enhanced by using a Clinical Laboratory Improvement Amendments of 1988-compliant assay and samples maintained at room temperature. METHODS: Cases with nondysplastic BE (NDBE), dysplastic BE (indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia), EAC, junctional adenocarcinoma, plus endoscopy controls without esophageal intestinal metaplasia, were prospectively enrolled. Medical assistants at 6 institutions delivered the encapsulated balloon per orally with inflation in the stomach. The inflated balloon sampled the distal 5 cm of the esophagus and then was deflated and retracted into the capsule, preventing sample contamination. EsoGuard bisulfite sequencing assayed levels of methylated vimentin and methylated cyclin A1. RESULTS: A total of 243 evaluable patients—88 cases (median age 68 years, 78% men, 92% White) and 155 controls (median age 57 years, 41% men, 88% White)—underwent adequate EsoCheck sampling. The mean procedural time was approximately 3 minutes. Cases included 31 with NDBE, 16 with indefinite for dysplasia/low-grade dysplasia, 23 with high-grade dysplasia, and 18 with EAC/junctional adenocarcinoma. Thirty-seven NDBE and dysplastic BE cases (53%) were short-segment BE (<3 cm). Overall sensitivity was 85% (95% confidence interval 0.78–0.93) and specificity was 85% (95% confidence interval 0.79–0.90). Sensitivity for NDBE was 84%. EsoCheck/EsoGuard detected 100% of cancers (n = 18). DISCUSSION: EsoCheck/EsoGuard demonstrated high sensitivity and specificity in detecting BE and BE-related neoplasia.

INTRODUCTION: A substantial proportion of patients with esophageal adenocarcinoma (EAC) do not report gastroesophageal reflux disease (GERD) symptoms. This study aimed to compare the risk factor profiles and cancer stage at presentation of patients with EAC with and without prior GERD. METHODS: In this retrospective cross-sectional study, patients with EAC were divided into 2 cohorts: (i) EAC with prior GERD: patients who reported typical GERD symptoms (heartburn or regurgitation) ≥1 year before cancer diagnosis and (ii) EAC without prior GERD: patients who did not report prior GERD symptoms or reported symptoms within 1 year of their cancer diagnosis. Baseline demographics, risk factors, and cancer stage at presentation were compared between the 2 cohorts. In addition, the distribution of patients based on numbers of BE/EAC–associated risk factors (1, 2, 3, 4, and 5 or more) was examined in the symptomatic and asymptomatic cohorts. RESULTS: Over 13 years, 388 patients with EAC with prior GERD and 245 patients with EAC without prior GERD were recruited. Both groups had similar baseline demographics and risk factors, but patients with EAC with prior GERD were more likely to have a history of BE. Asymptomatic patients had more advanced disease. Patients with 3 or more BE/EAC–related risk factors formed the largest proportion of patients in both the symptomatic and asymptomatic cohorts. DISCUSSION: Patients with EAC with and without prior GERD symptoms are phenotypically similar, suggesting that BE screening efforts to prevent or detect early EAC should not be restricted to just those with GERD.

Abstract Purpose: Current endoscopy-based screening and surveillance programs have not been proven effective at decreasing esophageal adenocarcinoma (EAC) mortality, creating an unmet need for effective molecular tests for early detection of this highly lethal cancer. We conducted a genome-wide methylation screen to identify novel methylation markers that distinguish EAC and high-grade dysplasia (HGD) from normal squamous epithelium (SQ) or nondysplastic Barrett's esophagus (NDBE). Experimental Design: DNA methylation profiling of samples from SQ, NDBE, HGD, and EAC was performed using HM450 methylation arrays (Illumina) and reduced-representation bisulfate sequencing. Ultrasensitive methylation-specific droplet digital PCR and next-generation sequencing (NGS)-based bisulfite-sequencing assays were developed to detect the methylation level of candidate CpGs in independent esophageal biopsy and endoscopic brushing samples. Results: Five candidate methylation markers were significantly hypermethylated in HGD/EAC samples compared with SQ or NDBE (P &lt; 0.01) in both esophageal biopsy and endoscopic brushing samples. In an independent set of brushing samples used to construct biomarker panels, a four-marker panel (model 1) demonstrated sensitivity of 85.0% and 90.8% for HGD and EACs respectively, with 84.2% and 97.9% specificity for NDBE and SQ respectively. In a validation set of brushing samples, the panel achieved sensitivity of 80% and 82.5% for HGD and EAC respectively, at specificity of 67.6% and 96.3% for NDBE and SQ samples. Conclusions: A novel DNA methylation marker panel differentiates HGD/EAC from SQ/NDBE. DNA-methylation–based molecular assays hold promise for the detection of HGD/EAC using esophageal brushing samples.

Objective An understanding of the etiologic heterogeneity of colorectal cancer (CRC) is critical for improving precision prevention, including individualized screening recommendations and the discovery of novel drug targets and repurposable drug candidates for chemoprevention. Known differences in molecular characteristics and environmental risk factors among tumors arising in different locations of the colorectum suggest partly distinct mechanisms of carcinogenesis. The extent to which the contribution of inherited genetic risk factors for CRC differs by anatomical subsite of the primary tumor has not been examined. Design To identify new anatomical subsite-specific risk loci, we performed genome-wide association study (GWAS) meta-analyses including data of 48 214 CRC cases and 64 159 controls of European ancestry. We characterised effect heterogeneity at CRC risk loci using multinomial modelling. Results We identified 13 loci that reached genome-wide significance (p<5×10 −8 ) and that were not reported by previous GWASs for overall CRC risk. Multiple lines of evidence support candidate genes at several of these loci. We detected substantial heterogeneity between anatomical subsites. Just over half (61) of 109 known and new risk variants showed no evidence for heterogeneity. In contrast, 22 variants showed association with distal CRC (including rectal cancer), but no evidence for association or an attenuated association with proximal CRC. For two loci, there was strong evidence for effects confined to proximal colon cancer. Conclusion Genetic architectures of proximal and distal CRC are partly distinct. Studies of risk factors and mechanisms of carcinogenesis, and precision prevention strategies should take into consideration the anatomical subsite of the tumour.

Abstract Background Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10−8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods We conducted a GWAS in European descent CRC cases and control subjects using a discovery–replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10−8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10−8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.

Combining DNA methylation markers with a swallowable device for sampling the distal esophagus effectively detects Barrett’s neoplasias.

Abstract 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.

AbstractBackgroundFamilial 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).MethodsWe 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.ResultsLinkage 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.ConclusionOur 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.

Abstract 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.