Multicenter, Prospective Trial of Nonendoscopic Biomarker-Driven Detection of Barrett's Esophagus and Esophageal Adenocarcinoma.

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.

Climate change: Attitudes and concerns of, and learnings from, people with neurological conditions, carers, and health care professionals.

OBJECTIVE: Concern about climate change among the general public is acknowledged by surveys. The health care sector must play its part in reducing greenhouse gas emissions and adapting to a changing climate, which will require the support of its stakeholders including those with epilepsy, who may be especially vulnerable. It is important to understand this community's attitudes and concerns about climate change and societal responses. METHODS: A survey was made available to more than 100 000 people among a section of the neurological community (patients, carers, and clinicians), focused on epilepsy. We applied quantitative analysis of Likert scale responses supported by qualitative analyses of free-text questions with crossover analyses to identify consonance and dissonance between the two approaches. RESULTS: A small proportion of potential respondents completed the survey; of 126 respondents, 52 had epilepsy and 56 explicitly declared no illness. The survey indicated concern about the impact of climate change on health within this neurological community focused on epilepsy. More than half of respondents considered climate change to have been bad for their health, rising to 68% in a subgroup with a neurological condition; over 80% expected climate change to harm their health in future. Most (>75%) believed that action to reduce greenhouse gas emissions will lead to improved health and well-being. The crossover analysis identified cost and accessibility as significant barriers. SIGNIFICANCE: The high level of concern about climate change impacts and positive attitudes toward policies to reduce greenhouse gas emissions provide support for climate action from the epilepsy community. However, if policies are implemented without considering the needs of patients, they risk being exclusionary, worsening inequalities, and further threatening neurological health and well-being.

Impact of the Percentage of Overlapping Surgery on Patient Outcomes: A Retrospective Cohort Study of 87,000 Surgical Cases.

OBJECTIVES: The primary objective of this study was to analyze the relationship of percentage of surgical overlap with patient outcomes to determine if a detrimental level of overlap exists. BACKGROUND: Overlapping surgery is defined as 1 attending physician supervising 2 or more operative cases simultaneously, without the critical portions of the cases occurring concurrently. To date, no study has examined the relationship of percent overlap, or the percentage of 1 case that is spent overlapping with another, to outcomes, efficiency, safety, and complications. METHODS: This study is a retrospective cohort study conducted at a large tertiary referral center. The primary outcomes of interest included operative duration, in-hospital mortality, 30-day readmission, and patient safety indicators (PSIs). The Cochran-Armitage test for trend was used to evaluate the outcomes of interest. P values of ≤0.05 were considered statistically significant. RESULTS: A total of 87,426 cases were included in this study. There were 62,332 cases without overlap (Group 0), 10,514 cases with 1% to 25% overlap (Group 1), 5303 cases with 26% to 50% overlap (Group 2), 4296 cases with 51% to 75% overlap (Group 3), and 4981 cases with >75% overlap (Group 4). In-hospital mortality decreased as overlap increased ( Ptrend <0.0001). Operative time increased with increasing overlap ( Ptrend <0.0001) while readmission rates showed no statistical significance between groups ( Ptrend =0.5078). Rates of PSIs were lower for Groups 1, 2, and 3 (1.69%, 2.01%, and 2.08%) when compared to Group 0 (2.24%). Group 4 had the highest rate of PSIs at 2.35% ( P =0.0086). CONCLUSION: Overlapping surgery was shown to have reduced in-hospital mortality and similar PSI and readmission rates when compared to nonoverlapping cases. Operative time was shown to increase in overlapping surgeries when compared to nonoverlapping surgeries. The results from this study indicate that the percentage of surgical overlap does not detrimentally affect most patient outcomes, especially with overlap of <75%.

The Ephrin B2 Receptor Tyrosine Kinase Is a Regulator of Proto-oncogene MYC and Molecular Programs Central to Barrett's Neoplasia.

BACKGROUND & AIMS: Mechanisms contributing to the onset and progression of Barrett's (BE)-associated esophageal adenocarcinoma (EAC) remain elusive. Here, we interrogated the major signaling pathways deregulated early in the development of Barrett's neoplasia. METHODS: Whole-transcriptome RNA sequencing analysis was performed in primary BE, EAC, normal esophageal squamous, and gastric biopsy tissues (n = 89). Select pathway components were confirmed by quantitative polymerase chain reaction in an independent cohort of premalignant and malignant biopsy tissues (n = 885). Functional impact of selected pathway was interrogated using transcriptomic, proteomic, and pharmacogenetic analyses in mammalian esophageal organotypic and patient-derived BE/EAC cell line models, in vitro and/or in vivo. RESULTS: The vast majority of primary BE/EAC tissues and cell line models showed hyperactivation of EphB2 signaling. Transcriptomic/proteomic analyses identified EphB2 as an endogenous binding partner of MYC binding protein 2, and an upstream regulator of c-MYC. Knockdown of EphB2 significantly impeded the viability/proliferation of EAC and BE cells in vitro/in vivo. Activation of EphB2 in normal esophageal squamous 3-dimensional organotypes disrupted epithelial maturation and promoted columnar differentiation programs, notably including MYC. EphB2 and MYC showed selective induction in esophageal submucosal glands with acinar ductal metaplasia, and in a porcine model of BE-like esophageal submucosal gland spheroids. Clinically approved inhibitors of MEK, a protein kinase that regulates MYC, effectively suppressed EAC tumor growth in vivo. CONCLUSIONS: The EphB2 signaling is frequently hyperactivated across the BE-EAC continuum. EphB2 is an upstream regulator of MYC, and activation of EphB2-MYC axis likely precedes BE development. Targeting EphB2/MYC could be a promising therapeutic strategy for this often refractory and aggressive cancer.

Patients With Esophageal Adenocarcinoma With Prior Gastroesophageal Reflux Disease Symptoms Are Similar to Those Without Gastroesophageal Reflux Disease: A Cross-Sectional Study.

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.

Computer-extracted features of nuclear morphology in hematoxylin and eosin images distinguish stage II and IV colon tumors.

We assessed the utility of quantitative features of colon cancer nuclei, extracted from digitized hematoxylin and eosin-stained whole slide images (WSIs), to distinguish between stage II and stage IV colon cancers. Our discovery cohort comprised 100 stage II and stage IV colon cancer cases sourced from the University Hospitals Cleveland Medical Center (UHCMC). We performed initial (independent) model validation on 51 (143) stage II and 79 (54) stage IV colon cancer cases from UHCMC (The Cancer Genome Atlas's Colon Adenocarcinoma, TCGA-COAD, cohort). Our approach comprised the following steps: (1) a fully convolutional deep neural network with VGG-18 architecture was trained to locate cancer on WSIs; (2) another deep-learning model based on Mask-RCNN with Resnet-50 architecture was used to segment all nuclei from within the identified cancer region; (3) a total of 26 641 quantitative morphometric features pertaining to nuclear shape, size, and texture were extracted from within and outside tumor nuclei; (4) a random forest classifier was trained to distinguish between stage II and stage IV colon cancers using the five most discriminatory features selected by the Wilcoxon rank-sum test. Our trained classifier using these top five features yielded an AUC of 0.81 and 0.78, respectively, on the held-out cases in the UHCMC and TCGA validation sets. For 197 TCGA-COAD cases, the Cox proportional hazards model yielded a hazard ratio of 2.20 (95% CI 1.24-3.88) with a concordance index of 0.71, using only the top five features for risk stratification of overall survival. The Kaplan-Meier estimate also showed statistically significant separation between the low-risk and high-risk patients, with a log-rank P value of 0.0097. Finally, unsupervised clustering of the top five features revealed that stage IV colon cancers with peritoneal spread were morphologically more similar to stage II colon cancers with no long-term metastases than to stage IV colon cancers with hematogenous spread. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Massively Parallel Sequencing of Esophageal Brushings Enables an Aneuploidy-Based Classification of Patients With Barrett's Esophagus.

BACKGROUND & AIMS: Aneuploidy has been proposed as a tool to assess progression in patients with Barrett's esophagus (BE), but has heretofore required multiple biopsies. We assessed whether a single esophageal brushing that widely sampled the esophagus could be combined with massively parallel sequencing to characterize aneuploidy and identify patients with disease progression to dysplasia or cancer. METHODS: Esophageal brushings were obtained from patients without BE, with non-dysplastic BE (NDBE), low-grade dysplasia (LGD), high-grade dysplasia (HGD), or adenocarcinoma (EAC). To assess aneuploidy, we used RealSeqS, a technique that uses a single primer pair to interrogate ∼350,000 genome-spanning regions and identify specific chromosome arm alterations. A classifier to distinguish NDBE from EAC was trained on results from 79 patients. An independent validation cohort of 268 subjects was used to test the classifier at distinguishing patients at successive phases of BE progression. RESULTS: Aneuploidy progression was associated with gains of 1q, 12p, and 20q and losses on 9p and 17p. The entire chromosome 8q was often gained in NDBE, whereas focal gain of 8q24 was identified only when there was dysplasia. Among validation subjects, a classifier incorporating these features with a global measure of aneuploidy scored positive in 96% of EAC, 68% of HGD, but only 7% of NDBE. CONCLUSIONS: RealSeqS analysis of esophageal brushings provides a practical and sensitive method to determine aneuploidy in BE patients. It identifies specific chromosome changes that occur early in NDBE and others that occur late and mark progression to dysplasia. The clinical implications of this approach can now be tested in prospective trials.

Carbon emission savings and short-term health care impacts from telemedicine: An evaluation in epilepsy.

OBJECTIVE: Health systems make a sizeable contribution to national emissions of greenhouse gases that contribute to global climate change. The UK National Health Service is committed to being a net zero emitter by 2040, and a potential contribution to this target could come from reductions in patient travel. Achieving this will require actions at many levels. We sought to determine potential savings and risks over the short term from telemedicine through virtual clinics. METHODS: During the severe acute respiratory syndrome coronavirus 2 (SARS-2-CoV) pandemic, scheduled face-to-face epilepsy clinics at a specialist site were replaced by remote teleclinics. We used a standard methodology applying conversion factors to calculate emissions based on the total saved travel distance. A further conversion factor was used to derive emissions associated with electricity consumption to deliver remote clinics from which net savings could be calculated. Patients' records and clinicians were interrogated to identify any adverse clinical outcomes. RESULTS: We found that enforced telemedicine delivery for over 1200 patients resulted in the saving of ~224 000 km of travel with likely avoided emissions in the range of 35 000-40 000 kg carbon dioxide equivalent (CO2 e) over a six and half month period. Emissions arising directly from remote delivery were calculated to be <200 kg CO2 e (~0.5% of those for travel), representing a significant net reduction of greenhouse gas emissions. Only one direct adverse outcome was identified, with some additional benefits identified anecdotally. SIGNIFICANCE: The use of telemedicine can make a contribution toward reduced emissions in the health care sector and, in the delivery of specialized epilepsy services, had minimal adverse clinical outcomes over the short term. However, these outcomes will likely vary with clinic locations, medical specialties and conditions.

Three-Dimensionally Printed Skin Substitute Using Human Dermal Fibroblasts and Human Epidermal Keratinocytes.

INTRODUCTION: Wound healing affects millions of people annually. After injury, keratinocytes from the wound edge proliferate, migrate, and differentiate to recapitulate the 3-dimensional (3D) structure needed to provide a barrier function. If the wound is too large, skin grafting may be required. We are interested in discovering novel strategies to enhance the wound healing process. It may be possible to recreate a viable and histologically accurate skin tissue using 3D printing. We hypothesize that keratinocytes and dermal fibroblasts can be bioprinted into a viable skin substitute. METHODS: Adult human dermal fibroblasts (HDFa) and adult human epidermal keratinocytes (HEKa) were cultured and subsequently printed with a 3D bioprinter within a hydrogel scaffold. After printing the HDFa and HEKa separately, cell viability and histological appearance were determined by sectioning the printed tissue and performing hematoxylin and eosin staining. The stained histological sections were analyzed for tissue morphology. RESULTS: The HEKa and HDFa cells suspended in the hydrogel were successfully printed into 3D scaffolds that resembled skin with hematoxylin and eosin staining. CONCLUSIONS: The HEKa and HDFa cells can be grown on 3D-printed hydrogels successfully. In addition, HEKa and HDFa cells can survive and grow when suspended in a hydrogel and 3D printed. Future potential applications of these results could lead to the creation of viable skin tissue for wound healing and surgical repair.

Systems Biology Analyses Show Hyperactivation of Transforming Growth Factor-ß and JNK Signaling Pathways in Esophageal Cancer.

BACKGROUND & AIMS: Esophageal adenocarcinoma (EAC) is resistant to standard chemoradiation treatments, and few targeted therapies are available. We used large-scale tissue profiling and pharmacogenetic analyses to identify deregulated signaling pathways in EAC tissues that might be targeted to slow tumor growth or progression. METHODS: We collected 397 biopsy specimens from patients with EAC and nonmalignant Barrett's esophagus (BE), with or without dysplasia. We performed RNA-sequencing analyses and used systems biology approaches to identify pathways that are differentially activated in EAC vs nonmalignant dysplastic tissues; pathway activities were confirmed with immunohistochemistry and quantitative real-time polymerase chain reaction analyses of signaling components in patient tissue samples. Human EAC (FLO-1 and EsoAd1), dysplastic BE (CP-B, CP-C, CP-D), and nondysplastic BE (CP-A) cells were incubated with pharmacologic inhibitors or transfected with small interfering RNAs. We measured effects on proliferation, colony formation, migration, and/or growth of xenograft tumors in nude mice. RESULTS: Comparisons of EAC vs nondysplastic BE tissues showed hyperactivation of transforming growth factor-ß (TGFB) and/or Jun N-terminal kinase (JNK) signaling pathways in more than 80% of EAC samples. Immunohistochemical analyses showed increased nuclear localization of phosphorylated JUN and SMAD proteins in EAC tumor tissues compared with nonmalignant tissues. Genes regulated by the TGFB and JNK pathway were overexpressed specifically in EAC and dysplastic BE. Pharmacologic inhibition or knockdown of TGFB or JNK signaling components in EAC cells (FLO-1 or EsoAd1) significantly reduced cell proliferation, colony formation, cell migration, and/or growth of xenograft tumors in mice in a SMAD4-independent manner. Inhibition of the TGFB pathway in BE cell lines reduced the proliferation of dysplastic, but not nondysplastic, cells. CONCLUSIONS: In a transcriptome analysis of EAC and nondysplastic BE tissues, we found the TGFB and JNK signaling pathways to be hyperactivated in EACs and the genes regulated by these pathways to be overexpressed in EAC and dysplastic BE. Inhibiting these pathways in EAC cells reduces their proliferation, migration, and formation of xenograft tumors. Strategies to block the TGFB and JNK signaling pathways might be developed for treatment of EAC.

Radiomic Features of Primary Rectal Cancers on Baseline T2 -Weighted MRI Are Associated With Pathologic Complete Response to Neoadjuvant Chemoradiation: A Multisite Study.

BACKGROUND: Twenty-five percent of rectal adenocarcinoma patients achieve pathologic complete response (pCR) to neoadjuvant chemoradiation and could avoid proctectomy. However, pretreatment clinical or imaging markers are lacking in predicting response to chemoradiation. Radiomic texture features from MRI have recently been associated with therapeutic response in other cancers. PURPOSE: To construct a radiomics texture model based on pretreatment MRI for identifying patients who will achieve pCR to neoadjuvant chemoradiation in rectal cancer, including validation across multiple scanners and sites. STUDY TYPE: Retrospective. SUBJECTS: In all, 104 rectal cancer patients staged with MRI prior to long-course chemoradiation followed by proctectomy; curated from three institutions. FIELD STRENGTH/SEQUENCE: 1.5T-3.0T, axial higher resolution T2 -weighted turbo spin echo sequence. ASSESSMENT: Pathologic response was graded on postsurgical specimens. In total, 764 radiomic features were extracted from single-slice sections of rectal tumors on processed pretreatment T2 -weighted MRI. STATISTICAL TESTS: Three feature selection schemes were compared for identifying radiomic texture descriptors associated with pCR via a discovery cohort (one site, N = 60, cross-validation). The top-selected radiomic texture features were used to train and validate a random forest classifier model for pretreatment identification of pCR (two external sites, N = 44). Model performance was evaluated via area under the curve (AUC), accuracy, sensitivity, and specificity. RESULTS: Laws kernel responses and gradient organization features were most associated with pCR (P ≤ 0.01); as well as being commonly identified across all feature selection schemes. The radiomics model yielded a discovery AUC of 0.699 ± 0.076 and a hold-out validation AUC of 0.712 with 70.5% accuracy (70.0% sensitivity, 70.6% specificity) in identifying pCR. Radiomic texture features were resilient to variations in magnetic field strength as well as being consistent between two different expert annotations. Univariate analysis revealed no significant associations of baseline clinicopathologic or MRI findings with pCR (P = 0.07-0.96). DATA CONCLUSION: Radiomic texture features from pretreatment MRIs may enable early identification of potential pCR to neoadjuvant chemoradiation, as well as generalize across sites. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Subtypes of Barrett's oesophagus and oesophageal adenocarcinoma based on genome-wide methylation analysis.

OBJECTIVE: To identify and characterise DNA methylation subtypes in oesophageal adenocarcinoma (EAC) and its precursor Barrett's oesophagus (BE). DESIGN: We performed genome-wide DNA methylation profiling on samples of non-dysplastic BE from cancer-free patients (n=59), EAC (n=23), normal squamous oesophagus (n=33) and normal fundus (n=9), and identified methylation subtypes using a recursively partitioned mixture model. We assessed genomic alterations for 9 BE and 22 EAC samples with massively parallel sequencing of 243 EAC-associated genes, and we conducted integrative analyses with transcriptome data to identify epigenetically repressed genes. We also carried out in vitro experiments treating EAC cell lines with 5-Aza-2'-Deoxycytidine (5-Aza-dC), short hairpin RNA knockdown and anticancer therapies. RESULTS: We identified and validated four methylation subtypes of EAC and BE. The high methylator subtype (HM) of EAC had the greatest number of activating events in ERBB2 (p<0.05, Student's t-test) and the highest global mutation load (p<0.05, Fisher's exact test). PTPN13 was silenced by aberrant methylation in the HM subtype preferentially and in 57% of EACs overall. In EAC cell lines, 5-Aza-dC treatment restored PTPN13 expression and significantly decreased its promoter methylation in HM cell lines (p<0.05, Welch's t-test). Inhibition of PTPN13 expression in the SK-GT-4 EAC cell line promoted proliferation, colony formation and migration, and increased phosphorylation in ERBB2/EGFR/Src kinase pathways. Finally, EAC cell lines showed subtype-specific responses to topotecan, SN-38 and palbociclib treatment. CONCLUSIONS: We identified and characterised methylator subtypes in BE and EAC. We further demonstrated the biological and clinical relevance of EAC methylator subtypes, which may ultimately help guide clinical management of patients with EAC.

Parental Origin of Interstitial Duplications at 15q11.2-q13.3 in Schizophrenia and Neurodevelopmental Disorders.

Duplications at 15q11.2-q13.3 overlapping the Prader-Willi/Angelman syndrome (PWS/AS) region have been associated with developmental delay (DD), autism spectrum disorder (ASD) and schizophrenia (SZ). Due to presence of imprinted genes within the region, the parental origin of these duplications may be key to the pathogenicity. Duplications of maternal origin are associated with disease, whereas the pathogenicity of paternal ones is unclear. To clarify the role of maternal and paternal duplications, we conducted the largest and most detailed study to date of parental origin of 15q11.2-q13.3 interstitial duplications in DD, ASD and SZ cohorts. We show, for the first time, that paternal duplications lead to an increased risk of developing DD/ASD/multiple congenital anomalies (MCA), but do not appear to increase risk for SZ. The importance of the epigenetic status of 15q11.2-q13.3 duplications was further underlined by analysis of a number of families, in which the duplication was paternally derived in the mother, who was unaffected, whereas her offspring, who inherited a maternally derived duplication, suffered from psychotic illness. Interestingly, the most consistent clinical characteristics of SZ patients with 15q11.2-q13.3 duplications were learning or developmental problems, found in 76% of carriers. Despite their lower pathogenicity, paternal duplications are less frequent in the general population with a general population prevalence of 0.0033% compared to 0.0069% for maternal duplications. This may be due to lower fecundity of male carriers and differential survival of embryos, something echoed in the findings that both types of duplications are de novo in just over 50% of cases. Isodicentric chromosome 15 (idic15) or interstitial triplications were not observed in SZ patients or in controls. Overall, this study refines the distinct roles of maternal and paternal interstitial duplications at 15q11.2-q13.3, underlining the critical importance of maternally expressed imprinted genes in the contribution of Copy Number Variants (CNVs) at this interval to the incidence of psychotic illness. This work will have tangible benefits for patients with 15q11.2-q13.3 duplications by aiding genetic counseling.

Performance of multitarget stool DNA testing in African American patients.

BACKGROUND: Multitarget stool DNA (mt-sDNA) is an approved method for colon cancer screening that is especially relevant for patients who cannot undergo colonoscopy. Although the test performance has been evaluated in a large clinical trial, it was limited to a predominantly white population. Given differences in the epidemiology and biology of colon cancer in African American individuals, the authors sought to compare the performance of mt-sDNA between racial groups. METHODS: The authors prospectively identified patients aged ≥40 years who were referred for colonoscopy at an academic medical center and 2 satellite facilities. Prior to the colonoscopy, the authors collected stool for mt-sDNA and fecal immunochemical testing (FIT). They compared the sensitivity, specificity, and receiver operating characteristic curve between African American and white patients for the detection of advanced lesions or any adenoma. RESULTS: A total of 760 patients were included, 34.9% of whom were African American. The prevalence of any adenoma (38.9% for African American patients and 33.9% for white patients) and that for advanced lesions (6.8% and 6.7%, respectively) were similar between groups. The overall sensitivities of mt-sDNA for the detection of advanced lesions and any adenoma were 43% and 19%, respectively, and the specificities were 91% and 93%, respectively. In general, mt-sDNA was more sensitive and less specific than FIT. When stratified by race, the sensitivity, specificity, and receiver operating characteristic curve area were similar between African American and white patients for both mt-sDNA and FIT. CONCLUSIONS: Test performance characteristics of mt-sDNA were comparable in African American and white patients. Given the lower uptake of colonoscopy in African American individuals, mt-sDNA may offer a promising screening alternative in this patient population.

Evaluation of Patients with an Apparent False Positive Stool DNA Test: The Role of Repeat Stool DNA Testing.

BACKGROUND: There is uncertainty as to the appropriate follow-up of patients who test positive on multimarker stool DNA (sDNA) testing and have a colonoscopy without neoplasia. AIMS: To determine the prevalence of missed colonic or occult upper gastrointestinal neoplasia in patients with an apparent false positive sDNA. METHODS: We prospectively identified 30 patients who tested positive with a commercially available sDNA followed by colonoscopy without neoplastic lesions. Patients were invited to undergo repeat sDNA at 11-29 months after the initial test followed by repeat colonoscopy and upper endoscopy. We determined the presence of neoplastic lesions on repeat evaluation stratified by results of repeat sDNA. RESULTS: Twelve patients were restudied. Seven patients had a negative second sDNA test and a normal second colonoscopy and upper endoscopy. In contrast, 5 of 12 subjects had a persistently positive second sDNA test, and 3 had positive findings, including a 3-cm sessile transverse colon adenoma with high-grade dysplasia, a 2-cm right colon sessile serrated adenoma with dysplasia, and a nonadvanced colon adenoma (p = 0.045). These corresponded to a positive predictive value of 0.60 (95% CI 0.17-1.00) and a negative predictive value of 1.00 (95% CI 1.00-1.00) for the second sDNA test. In addition, the medical records of all 30 subjects with apparent false positive testing were reviewed and no documented cases of malignant tumors were recorded. CONCLUSIONS: Repeat positive sDNA testing may identify a subset of patients with missed or occult colorectal neoplasia after negative colonoscopy for an initially positive sDNA. High-quality colonoscopy with careful attention to the right colon in patients with positive sDNA is critically important and may avoid false negative colonoscopy.

Novel recurrently mutated genes in African American colon cancers.

We used whole-exome and targeted sequencing to characterize somatic mutations in 103 colorectal cancers (CRC) from African Americans, identifying 20 new genes as significantly mutated in CRC. Resequencing 129 Caucasian derived CRCs confirmed a 15-gene set as a preferential target for mutations in African American CRCs. Two predominant genes, ephrin type A receptor 6 (EPHA6) and folliculin (FLCN), with mutations exclusive to African American CRCs, are by genetic and biological criteria highly likely African American CRC driver genes. These previously unsuspected differences in the mutational landscapes of CRCs arising among individuals of different ethnicities have potential to impact on broader disparities in cancer behaviors.

Combinatorial effects of multiple enhancer variants in linkage disequilibrium dictate levels of gene expression to confer susceptibility to common traits.

DNA variants (SNPs) that predispose to common traits often localize within noncoding regulatory elements such as enhancers. Moreover, loci identified by genome-wide association studies (GWAS) often contain multiple SNPs in linkage disequilibrium (LD), any of which may be causal. Thus, determining the effect of these multiple variant SNPs on target transcript levels has been a major challenge. Here, we provide evidence that for six common autoimmune disorders (rheumatoid arthritis, Crohn's disease, celiac disease, multiple sclerosis, lupus, and ulcerative colitis), the GWAS association arises from multiple polymorphisms in LD that map to clusters of enhancer elements active in the same cell type. This finding suggests a "multiple enhancer variant" hypothesis for common traits, where several variants in LD impact multiple enhancers and cooperatively affect gene expression. Using a novel method to delineate enhancer-gene interactions, we show that multiple enhancer variants within a given locus typically target the same gene. Using available data from HapMap and B lymphoblasts as a model system, we provide evidence at numerous loci that multiple enhancer variants cooperatively contribute to altered expression of their gene targets. The effects on target transcript levels tend to be modest and can be either gain- or loss-of-function. Additionally, the genes associated with multiple enhancer variants encode proteins that are often functionally related and enriched in common pathways. Overall, the multiple enhancer variant hypothesis offers a new paradigm by which noncoding variants can confer susceptibility to common traits.

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.

Magnetic resonance enterography/enteroclysis in acquired small bowel diverticulitis and small bowel diverticulosis.

PURPOSE: Small bowel (SB) diverticulosis is a rare disorder that may entail serious complications, including SB diverticulitis. Both are often missed in imaging. Magnetic resonance enterography/enteroclysis (MRE) is increasingly used to assess SB disease; awareness of the appearance of SB diverticulitis is essential to ensure appropriate management. Our aim was to systematically describe imaging characteristics of SB diverticulosis and diverticulitis in MRE. METHODS: This retrospective, HIPAA-compliant study identified 186 patients with suspected SB diverticulosis/diverticulitis in medical databases of two tertiary medical centres between 2005 and 2011. Patients with surgically confirmed diagnoses of SB diverticulosis/diverticulitis were included. Two observers analyzed MR images for the presence, location, number, and size of diverticula, wall thickness, and mural and extramural patterns of inflammation. RESULTS: Seven patients were recruited. MRI analysis showed multiple diverticula in all (100 %). Diverticular size ranged from 0.5 to 6 cm. Prevalence of diverticula was higher in the proximal than the distal SB (jejunum 86 %, ileum 57 %, distal ileum43%). Diverticulitis occurred in 3/7 patients (43 %) showing asymmetric bowel wall thickening and focal mesenteric inflammation. CONCLUSION: SB diverticulitis demonstrates characteristic MRE imaging features to distinguish this rare disorder from more common diseases. Asymmetric, focal mesenteric and mural inflammation and presence of multiple diverticula are keys to diagnosis. KEY POINTS: • Small bowel diverticulosis and diverticulitis is rare and often missed in imaging • Acquired small bowel diverticula are variable in size and number • Small bowel diverticulitis demonstrates characteristic features on MR enterography/enteroclysis • A focal or segmental asymmetric small bowel inflammation should prompt the search for diverticula.

Sulindac reversal of 15-PGDH-mediated resistance to colon tumor chemoprevention with NSAIDs.

Non-steroidal anti-inflammatory drugs prevent colorectal cancer by inhibiting cyclooxygenase (COX) enzymes that synthesize tumor-promoting prostaglandins. 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is a tumor suppressor that degrades tumor-promoting prostaglandins. Murine knockout of 15-PGDH increases susceptibility to azoxymethane-induced colon tumors. It also renders these mice resistant to celecoxib, a selective inhibitor of inducible COX-2 during colon neoplasia. Similarly, humans with low colonic 15-PGDH are also resistant to colon adenoma prevention with celecoxib. Here, we used aspirin and sulindac, which inhibit both COX-1 and COX-2, in order to determine if these broader COX inhibitors can prevent colon tumors in 15-PGDH knockout (KO) mice. Unlike celecoxib, sulindac proved highly effective in colon tumor prevention of 15-PGDH KO mice. Significantly, however, aspirin demonstrated no effect on colon tumor incidence in either 15-PGDH wild-type or KO mice, despite a comparable reduction in colonic mucosal Prostaglandin E2 (PGE2) levels by both sulindac and aspirin. Notably, colon tumor prevention activity by sulindac was accompanied by a marked induction of lymphoid aggregates and proximal colonic inflammatory mass lesions, a side effect seen to a lesser degree with celecoxib, but not with aspirin. These findings suggest that sulindac may be the most effective agent for colon cancer prevention in humans with low 15-PGDH, but its use may also be associated with inflammatory lesions in the colon.