Gary W. Falk

Understanding tissue development and intra-tissue evolution requires the ability to trace clones in intact tissues coupled with high-plex molecular profiling preserving spatial context. However, current lineage tracing tools are incompatible with spatial omics. Here, we present SUMMIT (Spatially Unveiling Mitochondrial Mutations In Tissues), a spatially-resolved lineage tracing technology that integrates gene expression profiling with mitochondrial mutation-based clone identification. Unlike synthetic lineage recording methods, SUMMIT relies only on endogenous mutations and thus can be applied to human tissues. To address the compositional mixing of cell types within spatial spots, SUMMIT includes a rigorous statistical framework to confidently assign variants to specific cell subpopulations and achieves high power for spatially localized clones by pooling information across neighboring spots. We validated SUMMIT using a controlled model in which we mixed two cancer cell lines in a mouse tumor, then demonstrated it on multiple human tissues including Barrett’s esophagus, gastric cardia, small bowel, and colorectal cancer. Across these samples, we distinguished between global mutations and mutations marking locally restricted clones. The coupled transcriptomic data allowed us to characterize the cell type composition within each clone and delineate their spatial configuration. This integrated approach provides a framework to understand spatially-defined clonal evolution in preserved human tissue.

INTRODUCTION: The effect of esophageal dilation history on efficacy outcomes in patients with eosinophilic esophagitis (EoE) receiving swallowed corticosteroids is not well established. METHODS: This post hoc analysis assessed data from a 12-week, randomized, double-blind, placebo-controlled phase 3 study (NCT02605837) of budesonide oral suspension (BOS) 2.0 mg twice daily in patients aged 11–55 years with EoE and dysphagia. Coprimary efficacy outcomes were histologic (≤ 6 eosinophils per high-power field [eos/hpf]) and dysphagia symptom (≥ 30% reduction in Dysphagia Symptom Questionnaire scores from baseline) responses at week 12. Secondary efficacy outcomes included histologic response (< 15 eos/hpf) and change from baseline to week 12 in Dysphagia Symptom Questionnaire scores and EoE Endoscopic Reference Scores. Data were analyzed post hoc by esophageal dilation history (dilation history vs no dilation history). RESULTS: Of 318 patients who received ≥ 1 dose of study drug, 42.8% had a history of esophageal dilation (dilation history: BOS, n = 91; placebo, n = 45; no dilation history: BOS, n = 122; placebo, n = 60). Histologic responses (≤ 6 and < 15 eos/hpf) were similar regardless of dilation history. Fewer BOS-treated patients with dilation history than no dilation history achieved a dysphagia symptom response (44.0% vs 59.0%); conversely, a slightly greater improvement from baseline in total EoE Endoscopic Reference Scores was observed for BOS-treated patients with dilation history than no dilation history (least-squares mean [SE of the mean]: −4.1 [0.3] vs −3.4 [0.4]). DISCUSSION: Esophageal dilation history may confound the association between histologic outcomes and dysphagia symptom or endoscopic efficacy outcomes in patients with EoE receiving swallowed corticosteroids.

INTRODUCTION: Reflux bile acids are believed to promote esophageal adenocarcinoma (EAC), but the role of systemic bile acids is unknown. This study aimed to assess associations between systemic bile acids and stages of Barrett's esophagus (BE) progression. METHODS: Subjects with and without BE were enrolled in this multicenter cross-sectional study. Targeted serum bile acid profiling was performed, and a subset of subjects completed a validated food frequency questionnaire. RNA sequencing was performed on BE or gastric cardia tissue to assess bile acid associations with gene expression. RESULTS: A total of 141 subjects were enrolled with serum bile acids profiled (49 non-BE; 92 BE: 44 no dysplasia, 25 indefinite/low grade dysplasia, 23 high-grade dysplasia/EAC). Lower Healthy Eating Index score, older age, higher body mass index, and no proton pump inhibitor use were associated with increased levels of multiple bile acids. Global bile acid pools were distinct between non-BE and stages of BE neoplasia (P = 0.004). Increasing cholic acid was associated with high-grade dysplasia/EAC compared with non-BE, even after adjusting for EAC risk factors (adjusted odds ratio 2.03, 95% confidence interval 1.11–3.71) as was the combination of unconjugated primary bile acids (adjusted odds ratio 1.81, 95% confidence interval 1.04–3.13). High cholic acid levels were associated with tissue gene expression changes including increased DNA replication and reduced lymphocyte differentiation genes. DISCUSSION: Alterations in serum bile acids are independently associated with advanced neoplasia in BE and may contribute to neoplastic progression. Future studies should explore associated gut microbiome changes, proneoplastic effects of bile acids, and whether these bile acids, particularly cholic acid, represent potential biomarkers or viable therapeutic targets for advanced neoplasia in BE.

INTRODUCTION: There are limited longitudinal data on the impact of chronic therapy on the natural history of eosinophilic esophagitis (EoE), a chronic allergic disease of the esophagus. The purpose of this study was to evaluate if patients with well-controlled EoE were less likely to develop fibrostenotic complications. METHODS: Subjects were identified from a database of pediatric patients with EoE at the Children's Hospital of Philadelphia started in 2000. Patients were then searched in adult medical records to identify patients who transitioned care. All office visits, emergency department visits, and endoscopic, histologic, and imaging reports were reviewed for the primary outcome of strictures and the secondary outcomes of food impactions and dysphagia. Cox proportional hazard regression was performed for outcomes. RESULTS: One hundred five patients were identified with the mean follow-up of 11.4 ± 4.9 years. 52.3% (n = 55) had a period of histologic disease control defined as ≥2 consecutive endoscopies with histologic remission. These patients were less likely to develop strictures compared with patients who did not have a period of histologic control (HR 0.232; 95% CI 0.084–0.64, P = 0.005). Patients who were diagnosed at younger ages were less likely to develop strictures. Presentation with dysphagia or impaction was associated with higher rate of stricture development. DISCUSSION: In this cohort study with > 10 years of follow-up, children with EoE with a period of histologic disease control and diagnosed at younger ages were less likely to develop esophageal strictures. While this suggests histologic remission is associated with reduction of remodeling complications, additional prospective data with long-term follow-up are needed.

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.

INTRODUCTION: Objective risk stratification is needed for patients with Barrett's esophagus (BE) to enable risk-aligned management to improve health outcomes. This study evaluated the predictive performance of a tissue systems pathology [TSP-9] test (TissueCypher) vs current clinicopathologic variables in a multicenter cohort of patients with BE. METHODS: Data from 699 patients with BE from 5 published studies on the TSP-9 test were evaluated. Five hundred nine patients did not progress during surveillance, 40 were diagnosed with high-grade dysplasia/esophageal adenocarcinoma (HGD/EAC) within 12 months, and 150 progressed to HGD/EAC after 12 months. Age, sex, segment length, hiatal hernia, original and expert pathology review diagnoses, and TSP-9 risk classes were collected. The predictive performance of clinicopathologic variables and the TSP-9 test was compared, and the TSP-9 test was evaluated in clinically relevant patient subsets. RESULTS: The sensitivity of the TSP-9 test in detecting progressors was 62.3% compared with 28.3% for expert-confirmed low-grade dysplasia (LGD), while the original diagnosis abstracted from medical records did not provide any significant risk stratification. The TSP-9 test identified 57% of progressors with nondysplastic Barrett's esophagus (NDBE) (P < 0.0001). Patients with NDBE who scored TSP-9 high risk progressed at a similar rate (3.2%/yr) to patients with expert-confirmed LGD (3.7%/yr). The TSP-9 test provided significant risk stratification in clinically low-risk patients (NDBE, female, short-segment BE) and clinically high-risk patients (IND/LGD, male, long-segment BE) (P < 0.0001 for comparison of high-risk classes vs low-risk classes). DISCUSSION: The TSP-9 test predicts risk of progression to HGD/EAC independently of current clinicopathologic variables in patients with BE. The test provides objective risk stratification results that may guide management decisions to improve health outcomes for patients with BE.