Gut

Background Endoscopic resection is used for the management of dysplasia in ulcerative colitis (UC), but a subset of patients develop subsequent advanced neoplasia (AN), i.e., high-grade dysplasia and/or colorectal cancer, despite apparently complete resection with histologically clear margins. Current risk stratification relies predominantly on histopathological and procedural features, which does not capture underlying genomic field cancerization of morphologically normal mucosa. Objective To determine whether genomic alterations within histologically non-dysplastic resection margins are associated with subsequent neoplastic progression following endoscopic resection of UC-associated dysplasia. Design We analysed a retrospective cohort of 51 UC patients, who underwent endoscopic resection of dysplastic lesions at a tertiary referral centre, with a median follow-up of 1947 days. 11 of these had local progression. We performed low-coverage whole genome sequencing (lcWGS) of 56 dysplastic lesions and 91 adjacent histologically non-dysplastic margins. Somatic copy number alteration (CNA) burden and phylogenetic analysis were correlated with progression to AN . Results Histologically non-dysplastic margins from lesions that subsequently progressed to AN demonstrated significantly higher CNA burden compared with non-progressors. In multivariate analysis high margin CNA burden was independently associated with local progression, whereas histologically clear resection margins and en bloc excisions were not. Conclusion Histological clearance does not necessarily indicate clearance of the cancerised field in UC-associated dysplasia. Genomic detection of field cancerisation within histologically non-dysplastic resection margins identifies patients at increased risk of subsequent neoplasia and provides a potential biomarker for biologically informed post-resection surveillance.

Biliary Atresia (BA) is the leading cause of pediatric liver transplantation. Given the heterogeneity of the disease, outcomes after diagnosis remain unpredictable. A multiscale atlas of BA hepatic tissue established early lymphatic dysplasia in infants that later proceed toward liver failure and transplantation (severe BA). An architecturally distorted, immature and CCL21-high lymphatic vasculature marked severe BA, along with an expanding cholangiocyte compartment pivoting toward immune-reactive MMP7/SOX9-high states. Hepatocyte-to-biliary transdifferentiation emerged broadly across BA- and non-BA-cholestatic injuries, while dedifferentiation and acute-phase-reactions were specific to severe BA. Functionally, lymphatic endothelial tissue, isolated from severe BA livers, induced an analogous LGR5- and SOX9-positive epithelial progenitor response when assembled with cholangiocytes as organoids. Further experiments revealed that lymphatic endothelium signals ectopically on liver epithelium via CCL21-CCR7-axis after BA-specific inflammatory priming. CCL21-depletion strategies mitigated the BA-specific MMP7-program. In sum, a maladaptive lymphatic endothelial dysplasia perturbs intrahepatic epithelium in severe BA and offers CCL21 as a possible target for epithelial stability.

Background: The organization of pancreatic cancer care may be associated with survival. Using health administrative claims data, we reconstructed the pathway from diagnosis to first-line therapy and examined associations of multidisciplinary team review and treatment at specialized centers with overall survival. Methods: Longitudinal historical cohort study using anonymized health administrative claims data from six Czech health insurance funds, covering approximately 17% of patients diagnosed with pancreatic cancer nationally between 2018 and 2020. Adults with an incident ICD-10 C25 record confirmed by imaging and histopathology were followed from the index date (the date of the first qualifying imaging or histopathological examination) until death, censoring, or 31 December 2021. Overall survival was analyzed using Kaplan-Meier methods and Cox regression adjusted for age and first-line therapy type. Results: Of 1,255 patients, 920 (73.3%) received first-line therapy and 266 (21.2%) died untreated. Among treated patients, 436 (47.4%) underwent multidisciplinary team review, 335 (36.4%) underwent surgery, and 667 (72.5%) were treated at a complex oncological center. Surgery was associated with longer overall survival than chemotherapy (age-adjusted hazard ratio [HR] 0.32, P < 0.001). Treatment at a complex oncological center was associated with longer overall survival (adjusted HR 0.77, 95% confidence interval [CI] 0.64-0.92, P = 0.004; crude median 532 versus 394 days). Multidisciplinary team review was not significantly associated with overall survival (adjusted HR 0.86, 95% CI 0.73-1.01, P = 0.073). Conclusions: Treatment at a complex oncological center was associated with longer survival, while fewer than half of patients had a recorded multidisciplinary team review. How care is organized, not only which therapy is delivered, is associated with outcome. The observational design and absence of key clinical covariates limit causal interpretation.

Background & Aims. Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiology whose prevalence varies >30-fold worldwide, peaking in Northern Europe and the U.S. Upper Midwest. This geographic distribution is not fully explained by recognized risk factors. We examine its correlation with Ixodes tick exposure. Approach & Results. PSC incidence across North America, Europe, and Oceania was compared with Lyme incidence, HLA-DRB1*03 frequency, latitude and other environmental factors. Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) were included as controls. A U.S. analysis (MarketScan, 2018-2022; 110.7 million person-years) correlated age and sex-standardized rates against 24 exposures, including Ixodes density and tick-borne infections, using ancestry-adjusted partial correlations. Cross-country PSC incidence tracked Lyme incidence (Spearman rho = 0.71-0.87); HLA-DRB1*03, AIH, and PBC did not. Alaska Native and Greenlandic populations, high-latitude but without established human exposure to Ixodes-borne pathogens, report no PSC despite high autoimmune liver disease and IBD. In the U.S., PSC was clustered and tracked Ixodes-borne pathogen incidence (ancestry-adjusted partial r, log scale: anaplasmosis +0.50, babesiosis +0.56, Powassan virus disease +0.52; in the Northeast-Midwest block, ancestry- and latitude-adjusted r = +0.72, +0.84, and +0.78, respectively). Non-Ixodes infections (Ehrlichia chaffeensis, spotted fever, tularemia), AIH, and PBC were null-to-negative; rural, agricultural, pollution, and healthcare-access also did not correlate. Conclusions. These ecological analyses are consistent with the hypothesis that Ixodes-borne pathogen exposure may trigger PSC. These ecological data cannot establish causation; they are hypothesis-generating, yielding falsifiable predictions for case control, serologic, and animal-model studies.

Acute (AP) and chronic (CP) pancreatitis are major causes of gastrointestinal morbidity. However, the genetic architectures of AP and CP remain incompletely defined, as does the degree to which the two conditions share a common genetic basis. Here we report a multi-population GWAS meta-analysis of both AP and CP across five biobanks, comprising 23,292 individuals with and 1,748,420 individuals without AP across five populations and 9,866 individuals with and 1,627,720 individuals without CP across three populations. We identified 16 and 14 genome-wide significant loci for AP and CP, respectively. Combining nearest-gene assignment, fine-mapping, MAGMA, and colocalization with pancreatic eQTLs, we prioritized 7 genes for AP and 5 genes for CP using two or more approaches, including three previously unreported candidates: TM4SF4 and TCIM for AP, and FFAR4 for CP. We demonstrated that AP and CP are strongly correlated at the genome-wide level (rg=0.89); however, we identified 44 regions with significantly lower correlations, including a region on chromosome 18 containing BCL2 with a negative local correlation. Plasma proteome-wide Mendelian randomization (MR) found 15 proteins whose genetically predicted plasma levels were associated with AP and 6 associated with CP, including ABO, whose measured levels likely proxy non-O blood type. Consistent with this, we found that non-O blood type was modestly but significantly associated with both AP and CP in an analysis of electronic health records from over 650,000 individuals. Finally, drug-target MR identified 38 and 45 target genes whose genetically predicted expression levels were associated with genetic liability for AP and CP, respectively. Among these, DRD2 and BCHE (for AP and CP, respectively) were also supported by colocalization analysis. Overall, these results expand the known genetic architecture of pancreatitis and identify tractable therapeutic targets.

Surgical decisions for intraductal papillary mucinous neoplasms (IPMNs), precursors of pancreatic cancer, depend on distinguishing low- from high-grade dysplasia, a distinction that molecular markers could refine. We microdissected 433 tumor regions from 135 patients and integrated transcriptomics, deep-learning histology, and KRAS/GNAS RNA-called variants. RNA programs and morphological motifs separated lesions by phenotype, intestinal versus others, rather than by dysplasia grade. Along gastric IPMN trajectories, low-grade lesions recapitulated the pit-chief polarity of normal gastric glands, whereas high-grade lesions were indistinguishable from pancreatobiliary lesions in morphology, RNA programs, and driver mutations. Intestinal IPMNs arose through two routes: a canonical GNAS-associated pathway and a KRAS-associated shift from low-grade gastric features, with lesions sharing driver mutations retaining common programs across phenotypes. Resolving these phenotypic trajectories clarified distinct progression paths and enabled phenotype-specific prediction of high-grade dysplasia in mucus aspirated from 94 resected lesions. These findings support a promising fluid-based assessment of IPMN status.

The aim of this study was to determine whether the frequency of metabolic dysfunction-associated steatotic liver disease (MASLD) and the severity profile of inflammatory bowel disease (IBD) differ across body mass index (BMI) categories. A retrospective analysis was performed using 400 inpatient medical records from 2023-2024 with verified ulcerative colitis or Crohn's disease and sufficient information on anthropometry, hepatic status, and intestinal disease activity. The cohort comprised 118 patients with normal BMI, 176 with overweight, and 106 with obesity. MASLD status was reconstructed from routine clinical documentation and required hepatic steatosis in the appropriate cardiometabolic context. Ultrasonography was the principal source of evidence for steatosis; laboratory findings, non-invasive indices, and elastography were considered supportive when available. Ulcerative colitis activity was assessed with the Mayo Score and Crohn's disease activity with the Crohn's Disease Activity Index; disease-specific results were harmonized into mild, moderate, and severe categories for pooled comparisons. MASLD was identified in 181 of 400 patients (45.3%). Its frequency increased from 20.3% in the normal-BMI group to 49.4% in the overweight group and 66.0% in the obesity group (chi2=49.29; p<0.001). The largest absolute increase, 29.1 percentage points, occurred between normal BMI and overweight. The proportion of severe IBD rose in the same order, from 6.8% to 14.8% and 32.1% across the three BMI strata (chi2=39.45; p<0.001). In unadjusted pairwise comparisons, the odds of MASLD were higher with overweight than with normal BMI (OR=3.83; 95% CI 2.24-6.55) and higher with obesity than with normal BMI (OR=7.62; 95% CI 4.17-13.91); obesity also differed from overweight (OR=1.99; 95% CI 1.21-3.28). These findings demonstrate an ordered BMI-related pattern in which MASLD becomes more frequent and severe IBD represents a larger share of cases. However, MASLD was still documented in approximately one fifth of patients with normal BMI, indicating that BMI is useful for clinical prioritization but not for excluding steatotic liver disease. Because the study was retrospective, liver assessment reflected routine care, and the effect estimates were not adjusted for treatment exposure, disease duration, or other metabolic covariates, the observed relationships should be interpreted as associations rather than causal effects.

Background Refractory coeliac disease type 1 (RCD1) lacks defining molecular markers, and the immune and epithelial mechanisms sustaining intestinal injury remain poorly understood. Objective To define the clonal immune and epithelial states that distinguish RCD1 from active coeliac disease (ACD) and determine their spatial organisation in the duodenal mucosa. Design We integrated single-cell RNA sequencing, CITE-seq surface proteomics and paired T-cell receptor sequencing of duodenal immune and epithelial compartments from Healthy controls (n = 6), ACD (n = 7), RCD1 (n = 9) and RCD2 (n = 2), with spatial transcriptomics in a subset of biopsies. Results RCD1 showed widespread TCR{beta} and TCR{gamma}{delta} clonal expansion across multiple IEL states, extending beyond previously defined mutation-bearing aberrant clones. Distinct IEL populations converged on a shared programme of adaptive persistence, innate-like signalling, metabolic fitness and cytoskeletal remodelling; GZMK expression marked both clonally expanded and non-clonal disease-associated states. In parallel, RCD1 epithelium showed loss of mature absorptive cell states and expansion of stress-associated, immune-interacting and regenerative programmes. Transit-amplifying cells acquired differentiation and tissue-remodelling signatures, while enteroendocrine cells expanded and developed a sensory-neurosecretory programme involving TRPA1, TRPV1, vesicle trafficking and NEUROD1 regulon activity. Spatial transcriptomics localised regenerative and enteroendocrine-associated epithelial programmes adjacent to immune-visible epithelial regions and KLRK1/GZMK-expressing IEL-rich niches in refractory tissue. Conclusion RCD1 represents a distinct mucosal state characterised by coordinated clonal IEL adaptation and epithelial remodelling, rather than simple amplification of ACD, providing a cellular framework for persistent tissue injury and disease stratification.

Background and study aims: Endoscopic assessment of ulcerative colitis (UC) is central to clinical decision-making however remains subjective and limited in characterisation of disease distribution. Artificial intelligence (AI) enables analysis of entire endoscopic examination, rather than relying on selected views. We aimed to develop and validate a deep learning model for automated assessment of UC severity from full-length endoscopic videos, introducing spatial representation of inflammation (Continuous Disease Score, CDS), and assess histological correlation. Patients and methods: Full-length endoscopy videos from adult patients with UC undergoing colonoscopy or flexible sigmoidoscopy were analysed; isolated proctitis was excluded. Videos were segmented and annotated using Mayo Endoscopic Score (MES) and Ulcerative Colitis Endoscopic Index of Activity (UCEIS). A deep learning model was trained for frame-level quality control and severity prediction, enabling analysis of full-length videos. Performance was evaluated using quadratic weighted kappa (QWK) and Cohen's kappa, with patient-level separation between datasets. CDS was derived from UCEIS predictions to quantify cumulative inflammatory burden, spatial extent of disease and histological prediction. Results: A total of 67 videos from 59 patients were included. The model demonstrated agreement for remission classification (MES=0 {kappa} 0.76; UCEIS[&le;]1 {kappa} 0.84). CDS enabled quantification of inflammatory burden and revealed spatial heterogeneity not reflected in categorical scores. Agreement with histology was strong (AUROC 0.84-0.87). Conclusions: AI-based analysis enables automated assessment of UC activity from full-length endoscopic videos, including remission detection and estimation of histological healing. CDS provides continuous characterisation of inflammatory burden and disease extent beyond conventional categorical scores, with potential to support more standardised assessment in clinical trials and practice.

Background and aimsCrohns disease (CD) is a highly heterogeneous disease. Patients with similar characteristics at baseline may end up on very different therapeutic and surgical paths. We aimed to identify disease-course trajectory phenotypes from a mix of clinical, treatment, surgical and comorbidity variables, and evaluate whether information already available at diagnosis could anticipate which trajectory a patient would follow. MethodsWe analysed a retrospective cohort of 98 unique CD patients enrolled at the IRCCS Ca Granda Policlinico Hospital, Milan. Factor analysis of mixed data (FAMD) was applied to 30 disease-course variables spanning demographic and Montreal descriptors, extra-intestinal manifestation burden, individual advanced-therapy drug exposures, surgical burden and comorbidity/symptom burden; clusters were then ranked by treatment burden using a line-weighted therapy score built separately from drug line positions and therapeutic-class weights. Clustering itself was carried out in the retained FAMD coordinate space, and cluster robustness was checked with silhouette metrics and bootstrap Jaccard stability. Baseline-associated variables were assessed separately, while advanced-therapy episodes were reconstructed from the therapy timeline. ResultsThree trajectory phenotypes emerged: C1 (n=56), C2 (n=31) and C3 (n=11). C3 was characterised by younger age at diagnosis, a heavier extra-intestinal manifestation burden, more intensive and prolonged therapy, greater biologic exposure and a higher cumulative number of surgeries, with comorbidity burden rising across the gradient. Montreal behaviour and comorbidity burden emerged as the strongest baseline correlate of trajectory membership, ahead of age at diagnosis and extra-intestinal manifestation burden; penetrating (B3) behaviour, notably, was actually more common in C1 than in C3. A model built on the diagnosis-available variables independently linked to trajectory membership (age at diagnosis, disease location and Montreal behaviour) showed moderate discrimination for the C3 trajectory (area under the curve, AUC=0.80, 95% CI 0.67-0.93). A sensitivity analysis that also added extra-intestinal manifestation count and comorbidity burden, whose timing relative to diagnosis we could not confirm, pushed discrimination to AUC=0.90. ConclusionsFAMD-space clustering identified stable, clinically interpretable CD-course trajectory phenotypes, including a small, high-burden C3 subgroup. This C3 trajectory, small, early-onset and treatment-refractory, shares clinical features that overlap with the difficult-to-treat CD phenotype, though C3 was derived by unsupervised clustering rather than validated against that frameworks own criteria; variables available at or near diagnosis showed exploratory discrimination for the high-burden C3 trajectory, though external validation and careful timing verification are needed before any clinical use.

Esophageal adenocarcinoma (EAC) has a poor five-year survival rate and one of the fastest-rising incidences of any cancer. The presence of dysplasia in Barrett's esophagus (BE) is the main risk factor for EAC development and guides clinical management. Unfortunately, the current histopathological diagnosis of dysplasia is unreliable, with poor inter-observer agreement, highlighting the need for novel biomarkers that can improve diagnostic accuracy. Here, we performed transcriptome profiling across the full spectrum of BE-related neoplasia in 85 samples to delineate gene expression alterations in progressively worse disease stages and identify biomarkers that could complement histopathology to improve the detection of dysplasia and EAC in endoscopic biopsy specimens. Differential gene expression and pathway analyses revealed that the most extensive transcriptional changes occurred during the transition from normal squamous (NSq) to non-dysplastic BE (NDBE), consistent with metaplastic transformation. Compared to NDBE, dysplasia was characterized by enhanced cellular growth and proliferation; upregulation of immune processes and oncogenic signaling pathways were present in EAC. Using machine learning approaches, we identified a novel five-gene panel suitable for a potential RNAseq-based diagnostic test (SLC11A1, IL36A, LUCAT1, MIR215, RNU6-954P) and performed an initial validation of this signature in an additional 51 samples. We also identified several potential novel immunohistochemical markers that may warrant further evaluation, including TREM1, CXCL5, OSM, and motilin. In summary, by delineating transcriptional changes across the full disease spectrum, this study identifies several candidate biomarkers for improving current diagnostic methods for Barrett's dysplasia and EAC.

Background and aimsPerianal fistulizing Crohns disease (pCD) affects 20% of patients with Crohns disease (CD) and severely impacts quality of life. Current therapies fail to provide sustained relief, and the molecular underpinnings of pCD remain poorly understood. This study aimed to elucidate the molecular landscape of perianal fistulas through multiomic profiling. MethodsPaired fistula-tract and adjacent rectal mucosal biopsies were collected from 63 patients (48 with pCD, 15 with cryptoglandular fistula [CPTGL]). Longitudinal sampling generated 101 unique molecular profiles, comprising of both RNA sequencing (RNA-seq) and 16S rRNA sequencing from both tissue sites, followed by integrative multiomics and gene network analyses. ResultsUnsupervised clustering revealed three patient clusters primarily defined by host gene expression, with minimal contribution from microbial profiles. Fistulae in clusters 1 and 2 showed strong immune activation and epithelial-mesenchymal transition (EMT). In contrast, cluster 3 fistulae displayed keratinization and metabolic reprogramming resembling psoriatic skin, together with reduced JAK-STAT signalling. Cluster 3 was enriched for patients classified as TOpClass:2a, who are more suitable for surgical repair (p = 0.02). Conversely, cluster 2, characterized by rectal keratinization and EMT in both fistula and rectum, showed the highest MRI inflammatory-mass score (p = 0.02) and a greater risk of subsequent ileostomy (Kaplan-Meier; p = 0.008). An independent RNAseq dataset validated the keratinization signature in a subset of pCD fistulae. ConclusionIntegrated multiomic analysis identified distinct molecular subtypes of pCD with surgical and therapeutic relevance. These findings refine the molecular understanding of pCD and support a precision medicine approach. What You Need to Know?O_ST_ABSBACKGROUND AND CONTEXTC_ST_ABSO_LIPerianal fistulas affect 1 in 5 Crohns disease patients and have a severe negative impact on the quality of life of the patients. C_LIO_LIMost advanced IBD therapies are not efficacious for perianal Crohns disease. C_LIO_LISurgical repair is not suitable for all patients. C_LI NEW FINDINGSO_LIThis study is the first to delineate molecularly defined patient subtypes in perianal fistulizing Crohns disease. It further characterizes a psoriasis-like keratinization program in a subset of fistulas. Finally, it identifies molecular features and histological indicators that may explain-and potentially help predict-favorable surgical outcomes in selected patients C_LI LIMITATIONSO_LIFunctional and mechanistic studies will be required to further dissect the drivers and dynamics of the epithelial remodeling identified. C_LI CLINICAL RESEARCH RELEVANCEO_LIRaises the possibility of refining of existing clinical stratification using molecular markers for improved therapeutic management and outcome. C_LI BASIC RESEARCH RELEVANCEO_LIProposes keratinization as an opposing molecular process to EMT within the perianal fistula tract. C_LIO_LIIdentifies robust gene signatures associated with EMT and keratinization in the fistula for further experimental and clinical studies. C_LI

Background: Each year, thousands of patients are diagnosed with gastrointestinal (GI) bleeding. Many of these patients undergo colonoscopy and are subsequently diagnosed with benign or malignant colorectal neoplasms. Aim of this study is to evaluate whether patients with cardiovascular comorbidities, many of whom are on anti-platelet or anticoagulation therapy, are more likely to be diagnosed with new benign or malignant colorectal neoplasms than patients without cardiovascular comorbidities. Methods : From the 2007-2011 NIS, 802,080 primary lower GI bleed admissions (ICD-9) were identified; 283,925 had cardiovascular comorbidities. We compared patients with vs without these comorbidities for the primary outcome of new benign or malignant colorectal neoplasms. Weighted analyses accounting for the complex survey design were performed in SAS 9.4, with trends assessed using Cochran-Armitage tests and linear regression and associations with colorectal cancer stage evaluated by multinomial logistic regression (p [&le;] 0.05). Results: Between 2007-2011, the odds of malignant colorectal neoplasms increased between 49.9% and 65.3% for patients without cardiovascular comorbidities when presenting with a lower GI bleed, compared to those with cardiovascular comorbidities. Between 2007 and 2011, the most notable and statistically significant difference was observed in 2010, when patients with cardiovascular comorbidities had 10.5% higher odds of being diagnosed with benign colorectal neoplasms than those without cardiovascular comorbidities. Conclusion: Patients presenting with a lower gastrointestinal bleed without cardiovascular comorbidities were significantly more likely to be diagnosed with malignant colorectal neoplasms than those with cardiovascular comorbidities.

Background: Inflammatory bowel disease (IBD) has been linked to a two- to eightfold increase in colorectal cancer (CRC) risk. However, particular genes that bridge intestinal dysbiosis and oncogenic transcriptional reprogramming remain unclear. The Hippo/YAP pathway is a major regulator of intestinal epithelial homeostasis whose effector YAP is hyperactivated in CRC, but its transcriptional engagement in IBD mucosa and its link to specific cancer-risk genes has not been thoroughly mapped. Methods: Bulk RNA-seq data were integrated from two independent cohorts: GSE235236 (IBD colon mucosa; UC/CD vs. healthy controls; n = 56) and TCGA-COAD/READ (CRC tumors stratified by YAP activity; n = 592). Differential expression analysis was conducted separately within each cohort using Welch's t-test with Benjamini-Hochberg FDR correction. YAP transcriptional activity was estimated per sample as the mean row-wise Z-score of seven canonical YAP target genes, and TCGA tumors were stratified into Hippo-High (Q4) and Hippo-Low (Q1) groups. Genes showing consistent dysregulation across both cohorts were identified and ranked to define a Dysbiosis-Hippo Response (DHR) module, which was further organized into functional gene archetypes. Results: IBD mucosa showed 2,848 significantly dysregulated genes (FDR < 0.05). Comparison with the CRC cohort identified 120 genes showing concordant dysregulation, forming the DHR module. These genes were significantly enriched in TNF-alpha signaling via NF-kB (adjusted p = 0.006), inflammatory response (adjusted p = 0.013), and Myogenesis (adjusted p = 0.013). DHR gene classification revealed three functional archetypes: (i) innate immune activation (SPI1, OSM, IL11, LILRA2, SLC11A1) reflecting convergent myeloid reprogramming; (ii) epithelial-mesenchymal transition (TWIST1, SNAI1, PRRX2, MMP9) priming invasive potential before malignancy; and (iii) tumor microenvironment immune regulation (TN-FRSF4, TNFRSF18, PDCD1, VASN, SPON2) shaping immune tolerance. Interestingly, the canonical YAP target genes (CTGF, CYR61, ANKRD1, AMOTL2, and FSTL1), sharply upregulated in Hippo-High CRC, were essentially unchanged in IBD mucosa. This signifies that the shared DHR programme operates through non-canonical YAP effectors. And yet, YAP target scores are positively correlated with DHR module expression across IBD samples (Spearman rho = 0.726, p = 2.5 x 10-10). Conclusions: Our findings define a three-archetype DHR module that links gut dysbiosis to YAP-driven oncogenesis at single-gene resolution. The programme shared between IBD and CRC is driven by innate immune activation, EMT priming, and remodeling of the immune microenvironment, not by the canonical CTGF/CYR61 YAP target axis, which appears only at the CRC stage. This gene-level framework provides tractable mechanistic targets for chemoprevention and biomarker development at the inflammation-to-cancer transition.

Introduction Patients undergoing polypectomy at colonoscopy remain at risk of metachronous neoplasia despite surveillance guided by histopathological features. Mutational profiling of adenomas, including canonical driver mutations in APC, KRAS, and TP53, may offer additional predictive value. This study aimed to determine whether mutational status in index adenomas was associated with metachronous lesion risk. Methods The INCISE cohort included patients aged 50 to 74 years who underwent polypectomy within the Scottish Bowel Screening Programme and subsequent surveillance colonoscopy within 6 years. Targeted next-generation sequencing was performed on formalin-fixed paraffin-embedded polyps. Driver mutation frequency, tumour mutational burden (TMB), and variant allele frequency (VAF) were analysed and correlated with histopathological features and metachronous outcomes using appropriate statistical models. Results A total of 895 adenomas from 723 patients were analysed. In conventional adenomas, as the number of high-risk histopathological features (size >=10mm, villous architecture, and high-grade dysplasia) increased there was a stepwise increase in the proportion of samples with a mutation in KRAS from 13% to 51% (padj<0.001) and TP53 from 8% to 35% (padj<0.001). However, neither mutation frequency (p=0.901), nor median tumour mutation burden (TMB) (2.27 vs 2.15 mut/Mb, p=0.242), in index adenomas was associated with the development of metachronous lesions. Conclusions While classical driver mutations reflect histopathological progression within adenomas, they do not predict metachronous lesion risk post-polypectomy. Targeted mutation profiling alone is insufficient for surveillance risk stratification, highlighting the need for integrated molecular approaches in this setting.

Background: Colorectal polyps judged endoscopically unresectable are conventionally referred for colectomy, carrying substantial morbidity for a lesion that is usually benign. Advanced endoscopic techniques have made many such lesions resectable, but the burden and temporal trends of surgery remain unclear. Methods: PubMed, Scopus, Embase, Web of Science, and Cochrane CENTRAL were searched from inception to 1 September 2026 for studies reporting surgery for endoscopically unresectable polyps against a population or health system denominator. Estimates were assigned a priori to four denominator classes: population at risk (N1), colorectal resections (N2), polyps detected (N3), or colonoscopies/screening episodes (N4). Estimates were analysed within class and never combined across classes. Within denominator sub-definitions containing at least three independent data sources, proportions were pooled using random-effects models on the logit scale with restricted maximum likelihood estimation of between study variance, Hartung Knapp adjusted confidence intervals and 95% prediction intervals. Risk of bias was assessed using the JBI checklist for prevalence studies and certainty using an adapted GRADE approach. Results: Eighteen studies contributed 122 burden estimates; 105 of 130 full texts were excluded for lacking a population or health-system denominator. 75 distinct denominator definitions were identified. Estimates ranged from 1.09% to 38.38% of colorectal resections and 0.09% to 52.38% of polyps detected. Seven studies reported one numerator against multiple denominators, producing within-study differences of up to 88.3 fold. When denominators matched, estimates converged: 12 values from two national datasets spanned only 0.20% to 0.37% of unselected colonoscopy volume. Unresectability criteria were reported in 7 of 17 assessable studies; only one satisfied all five reporting items. Three sub-definitions contained enough independent sources to pool, and every pooled estimate carried a wide prediction interval: 23.79% (95% CI 12.27 to 41.06; 95% prediction interval 3.22-74.55) of resections for colorectal neoplasia, 1.15% (0.31 to 4.21; 0.02 to 37.19) of all detected polyps and 17.11% (4.36 to 48.30; 0.31 to 93.22) of large or complex lesions. Restricting estimates to a single denominator sub-definition reduced between-study variance by 53% among polyp based denominators. Conclusions: The burden of surgery for endoscopically unresectable colorectal polyps cannot presently be expressed as a single figure. Published disagreement is primarily definitional, with estimates converging when denominators match. Surgical volume appears to have peaked around 2012 to 2014 and subsequently declined. A minimum reporting standard is needed to measure this burden reliably.

Liver cancer remains a major global health burden with high mortality and limited treatment response prediction tools. Patient-derived cancer organoids have emerged as promising preclinical models that recapitulate tumor heterogeneity; however, the biological significance of morphological diversity within established organoids remains poorly characterized in hepatocellular carcinoma (HCC). In this exploratory study, we investigated whether distinct organoid growth phenotypes reflect underlying tumor biology and correlate with clinical outcomes. We established liver cancer organoids from resected tumor tissues of 27 patients and analyzed their clinical, histological, and genomic characteristics. Organoids were classified morphologically into cystic and solid types. Whole exome sequencing (WES) was conducted on six matched tumor-organoid pairs to assess genomic fidelity. Associations between organoid establishment, growth characteristics, and clinical parameters were statistically evaluated. Progression-free survival (PFS) was analyzed using the Kaplan-Meier method and univariate Cox proportional hazards regression. Organoids were successfully established in 13 of 27 cases (48.1%). Solid-type organoids were significantly associated with shorter PFS compared to cystic types (HR = 13.91; p = 0.0039, log-rank test). Organoid establishment was more frequent in older patients (>70 years), those with HBV infection, and tumors with positive {beta}-catenin expression. WES analysis demonstrated high concordance in somatic mutation profiles and variant allele frequency distributions between tissues and corresponding organoids. In univariate Cox regression, organoid growth pattern (solid vs. cystic) showed a significant association with PFS within this exploratory cohort (p = 0.0207). Patient-derived liver cancer organoids preserved the genomic and histopathological features of the original tumors. Notably, solid morphology was associated with shorter PFS, suggesting that organoid growth phenotype may serve as a supplementary indicator of tumor biological behavior in HCC. Given the modest cohort size and the absence of multivariate analysis, these preliminary findings should be interpreted with caution and warrant further large-scale validation.

Progressive hepatic fibrosis is the principal determinant of morbidity and mortality in metabolic dysfunction-associated steatotic liver disease and steatohepatitis (MASLD/MASH). Mitochondrial dysfunction is a hallmark of MASH, and the release of mitochondrial damage-associated molecular patterns (mito-DAMPs) from injured hepatocytes can promote fibrosis. However, how mitochondrial dynamics and quality control shape the fibrotic response in MASLD/MASH remains unclear. Here, through large-scale genomic analyses of mitochondrial genes governing mitophagy, fusion and fission in human MASLD, with a power-equivalent sample size of approximately 700,000 individuals, we identify a strong association between hepatic fibrosis and the mitochondrial fusion factor dynamin-like GTPase optic atrophy 1 (OPA1). OPA1 transcripts and protein abundance in the liver epithelium were progressively dysregulated with advancing fibrosis. In mice, hepatocyte-specific OPA1 loss alone was sufficient to induce hepatic stellate cell activation and fibrosis in zone 3, promoted the release of mito-DAMPs into the circulation and exacerbated fibrosis in experimental MASH. These findings identify OPA1 as a central regulator of the hepatic fibrotic response and connect defective mitochondrial homeostasis to mito-DAMP release, hepatic stellate cell activation and fibrosis in MASLD.

Background: Neoadjuvant chemotherapy (NAC) is increasingly incorporated into the management of pancreatic ductal adenocarcinoma (PDAC), yet how treatment regimen and timing reshape the tumour-immune microenvironment remains poorly defined. Methods: Targeted immune transcriptomic profiling was performed using NanoString on spatially annotated tumour, stromal, and immune-enriched regions from resected PDAC specimens from 23 patients, including NAC-treated and treatment-naive cohorts. Key findings were validated and spatially localised using Xenium in situ transcriptomics. Results: NAC induced extensive transcriptional remodelling of the tumour microenvironment in a regimen- and time-dependent manner. Tumours resected shortly after FOLFIRINOX exhibited coordinated upregulation and strong spatial coupling of the CXCL12-CXCR4 axis. These correlations were attenuated or reversed at longer post-treatment intervals and following gemcitabine-based therapy. Disrupted stromal coordination of the CCL2-CCR2 axis further highlighted context-dependent effects of chemotherapy on chemokine signalling. Across regions, NT5E (CD73) expression inversely correlated with CD8A, consistent with spatially restricted T cell exclusion. Conclusions: NAC dynamically reprograms the immunestromal landscape of PDAC in a regimen- and timing-dependent manner, revealing a transient post-chemotherapy window of immune remodelling. The clinical significance of this phenomenon requires further investigation to determine whether temporally optimised integration of immunomodulatory and stroma-targeted therapies with NAC can improve patient outcomes.

Fluid accumulates within serosal cavities in diverse disease states, where it creates biologically active and potentially pathologic niches. How these expanded microenvironments reflect and shape disease biology remains incompletely resolved. Here, we investigated human ascites fluid (n = 118), a hallmark of decompensated cirrhosis, to determine whether signatures of microbial exposure and local host response distinguish outcomes. Cirrhotic ascites was characterized by barrier remodeling, depletion of plasma cell-associated programs, and enrichment of oropharyngeal microbes. Surprisingly, detection of oropharyngeal microbes in ascites was not associated with adverse outcomes. Instead, the ascites of cirrhotic patients with poor outcomes was marked by profound plasma cell depletion and significantly reduced dimeric IgA, despite the presence of antigen-experienced B cells. Together, these findings identify local B cell dysregulation as a previously underappreciated component of cirrhosis-associated immune dysfunction. Impaired local humoral immunity, rather than microbial translocation alone, emerges as a feature of high-risk decompensated cirrhosis.