Introduction

A tumor-positive vertical margin (R1v) is considered a risk factor for residual cancer after endoscopic resection (ER) of early neoplasia in Barrett’s esophagus (BE). Additional surgery is advocated after an R1v resection, but often no residual tumor is detected in the surgical resection specimen. In this study, we aimed to assess the risk of local residual cancer in patients with a histologically confirmed R1v after ER.

Aims & Methods

We included patients treated with ER for BE neoplasia since 2008 in the nationwide Dutch Barrett Expert Centers, with documented R1v. Digital pathology slides of the resection specimens were reassessed by 4 expert pathologists until consensus was reached regarding the vertical resection margin. Vertical R1 resections were defined as cancer cells touching the vertical margin. The primary outcome was the presence of residual cancer.

Results

110 patients were included, which were treated with EMR (n=73) and ESD (n=37) for T1a (n=20) and T1b (n=88) cancer. Pathology slides of 108/110 (98%) ER specimen could be retrieved for reassessment. R1v margins were confirmed in 79 patients (73%), while the vertical margins in the remaining cases were Rx (19%; 20/108) and R0 (8%; 9/108). Reasons for doubtful or not assessable (Rx) vertical margins included tangential cutting (30%), suboptimal embedding (25%), curled lateral margins (14%), and cauterization artefacts (14%). The presence of residual cancer was unknown in 8/79 patients with confirmed R1v, due to treatment with adjuvant chemoradiotherapy (n=3) or no follow-up (n=5). Among the remaining patients with confirmed R1v (n=71), residual neoplasia was present in 36 (51%) patients. First endoscopic scar assessment detected all residual cancers in patients treated with additional surgery after ER (n=6). The risk of residual cancer was higher but not significantly increased with increasing tumor width in the vertical margin in univariate analysis (P=0.059).

Conclusion

No residual cancer was present in 49% of the patients with a confirmed vertical R1 margin after endoscopic resection. The pathological assessment of vertical R1 margins appears challenging, as only 73% of documented vertical R1 cases were confirmed during reassessment. The tumor width in the vertical margin might be useful to identify patients at highest risk of residual cancer after ER with R1v.

Introduction

Irritable bowel syndrome (IBS) is defined as a disorder of gut-brain interaction (DGBI) and is characterised by intestinal immune activation, increased intestinal permeability, and structural and functional brain alterations. DGBI patients have a higher prevalence of psychological comorbidities. Nevertheless, the exact pathophysiological link between these factors and the sequence of events is unknown. Gut alterations have been suggested to induce brain neuroinflammation in DGBI, but scientific evidence is lacking.

Aims & Methods

The present study aims to assess whether GI alteration induces brain neuroinflammation, alters brain function, and, consequently, induces psychological comorbidities. A unique longitudinal study was conducted from 30 to 220 days of age to establish the chronological sequence of intestinal and neurological changes. For this, we utilised the BioBreeding diabetes-prone (BBDP) rat model, which spontaneously develops intestinal inflammation, increased permeability, and colonic hypersensitivity^{1, 2}and has been employed as a model of DGBI. The BioBreeding diabetes-resistant (BBDR) was used as control. Anxiety-like behaviour was assessed using the elevated plus maze. Intestinal permeability was assessed in vivo by measuring the passage of 4 kDa and 70 kDa dextrans into the blood, thereby evaluating paracellular and transcellular permeability, respectively. The appearance of red colour, given by the mixture of the dextrans in the stools, was used to assess overall intestinal motility. The blood-brain barrier (BBB) integrity and brain metabolic profile were assessed using contrast-enhanced magnetic resonance imaging (0.25 mL/100g weight of 0.05 mM, gadolinium) and proton magnetic resonance spectroscopy, respectively.

Results

BBDP rats exhibit an increased colonic permeability starting from 90 days, and reduced GI motility at 90 and 160 days. Interestingly, this increased permeability is accompanied by an increased BBB permeability at 220 days only in the anterior cingulate cortex (ACC) but not in the hippocampus, insula, amygdala, or thalamus. BBDP rats showed a slight increase in total choline and myoinositol concentrations in the ACC and the insula at late time points, which may indicate increased neuroinflammation. BBDP rats also have higher concentrations of glutamine-glutamate in the insula and N-acetyl aspartate in the ACC. Moreover, BBDP rats develop anxiety-like behaviour at 160 and 220 days.

Conclusion

The BBDP rat model supports the current hypothesis that increased gut permeability can lead to brain neuroinflammation, altered function, and, consequently, to psychological comorbidities.
EU-funded DISCOvERIE project (No. 848228).

References

1. Meleine M, Accarie A, Wauters L, et al. Colonic hypersensitivity and low-grade inflammation in a spontaneous animal model for functional gastrointestinal disorders. Neurogastroenterol Motil 2019;31:e13614.
2. Vanuytsel T, Vanormelingen C, Vanheel H, et al. From intestinal permeability to dysmotility: the biobreeding rat as a model for functional gastrointestinal disorders. PLoS One 2014;9:e111132.

Introduction

Inflammatory bowel disease (IBD) is characterised by inflammatory flares with excruciating pain, for which effective analgesics are lacking. Cocaine- and amphetamine-regulated transcript (CART) peptide regulates peripheral pain in mice.¹ However, its role in visceral nociception as well as the underlying molecular signalling mechanism in primary sensory neurons remains elusive. CART is highly expressed in TRPV1-positive colon-projecting sensory neurons.² In addition, the enzyme prohormone convertase 1/3, which is involved in processing CART into its bioactive fragment 55-102, is upregulated in colonic biopsies of IBD patients (internal data), suggesting a potential role for the peptide in colonic pain.

Aims & Methods

Here, we aimed to test if CART would affect firing of the colon-innervating lumbar splanchnic nerve (LSN) as model of visceral nociception and characterise its effect and signalling pathway in sensory neurons innervating the colon. Studies were performed using tissue from male and female C57BL/6J mice euthanised by cervical dislocation and exsanguination in accordance with Schedule 1 of the Animals (Scientific Procedures) Act 1986. Thoracolumbar dorsal root ganglia (DRG) neurons were dissociated and cultured overnight for Ca²⁺ imaging using Fluo-4 AM as previously described.³ Cells were perfused with extracellular solution (ECS) alone or supplemented with either rat CART 55-102, (20-300nM, ECS), thapsigargin (10mM, DMSO), xestospongin C (1mM, ECS), edelfosine (10mM, ECS), capsaicin (10mM, ethanol) or KCl solution (60mM, ddH₂O) for respective challenge or pre-treatment. All conditions were blinded and randomised. Colorectum with attached lumbar splanchnic nerve was carefully removed and mounted on a tissue bath superfused with Krebs buffer as previously described.³ Rat CART 55-102 was superfused at 5ml/min, resulting in a final concentration of 200nM. Statistical analysis was performed using Student´s t test or ANOVA and Dunnett´s multiple comparisons test. Data is displayed as mean ± SEM.

Results

CART elicited a concentration-dependent increase in intracellular Ca²⁺ in DRG neurons, which at the highest concentration tested (300nM) induced a significant increase in intracellular Ca²⁺ in 29.2 ± 2.98% of DRG neurons relative to 8.35 ± 1.25% of vehicle responders (p < 0.0001). 55.05% of CART-responsive neurons were putative nociceptors due to co-sensitivity to capsaicin. Further investigation revealed a statistically significant reduction in the proportion of CART-sensitive neurons compared to CART (300nM) alone following pre-treatment with edelfosine, a phospholipase C inhibitor (10.5 ± 3.88%, p = 0.006), thapsigargin, a SERCA pump inhibitor (7.25 ± 1.78%, p = 0.001), or xestospongin C, an inositol triphosphate receptor inhibitor (6.74± 1.87%, p = 0.006). Furthermore, tissue bath application of CART (200nM) elicited a marked transient increase in ongoing LSN discharge, which increased from a baseline of 12.8 ± 3.9 (spikes/s) to a peak firing of 19.7 ± 6.1 spikes/s (p = 0.0385).

Conclusion

CART stimulates intracellular Ca²⁺ release in capsaicin-sensitive neurons consistent with a role in pain processing. This response was mediated by the release of Ca²⁺ from intracellular stores such as the endoplasmic reticulum and attenuated by inhibitors of the G_q pathway, suggesting activation of a G_q-coupled GPCR. The pronociceptive activity of CART on nerve firing suggests a potential role in colonic pain. Further research is necessary to identify the role of CART in IBD.

References

1. Ohsawa M, Dun SL, Tseng LF, Chang J, Dun NJ. Decrease of hindpaw withdrawal latency by cocaine- and amphetamine-regulated transcript peptide to the mouse spinal cord. Eur J Pharmacol. Jul 7 2000;399(2-3):165-9. doi:10.1016/s0014-2999(00)00374-5
2. McGuire C, Boundouki G, Hockley JRF, et al. Ex vivo study of human visceral nociceptors. Gut. Jan 2018;67(1):86-96. doi:10.1136/gutjnl-2016-311629
3. Higham JP, Bhebhe CN, Gupta RA, et al. Transcriptomic profiling reveals a pronociceptive role for angiotensin II in inflammatory bowel disease. Pain. Jan 29 2024;doi:10.1097/j.pain.0000000000003159

Disclosure

The PhD research is partially funded by Metrion Biosciences.

Introduction

Chronic intestinal pseudo-obstruction (CIPO) is a rare disease where impaired propulsive activity of the gut leads to bowel dilatation without an anatomical obstruction. There is no single assessment that comprehensively assesses the severity of symptoms and their impact on patients. Our aim was to develop a CIPO-specific electronic patient-reported outcome (ePRO), the CIPO Daily Diary^© (CIPO eDD), for clinical trials.

Aims & Methods

The CIPO eDD was developed per FDA guidelines^1,2 in a noninterventional, cross-sectional, qualitative interview study. This multi-stage process started with a targeted literature review and GAP analysis, with subsequent input from experts and patients. Literature reviews identified key signs and symptoms, and outcomes previously used in CIPO. Interviews with 3 clinicians experienced in diagnosing and treating CIPO, and insights from a steering committee that included the 3 clinicians and 2 external consultants, identified draft elements for the CIPO eDD. The draft CIPO eDD underwent iterative (4 rounds) hybrid concept elicitation (CE)/cognitive interviews and usability testing (CIUT) with patients from the USA (aged 18–80 years) with physician-confirmed CIPO diagnosis. For CE, patients answered open-ended questions about their CIPO experiences. CIPO signs, symptoms and impacts (concepts) emerged spontaneously from the responses. For CIUT, patients completed the CIPO eDD and reviewed the comprehensiveness, relevance and clarity of items. Textual analysis of interview transcripts guided amendments to the CIPO eDD items based on patient feedback. Following the initial CE/CIUT interviews, the same patients answered follow-up questions about the draft CIPO eDD to refine the items and to obtain qualitative and preliminary quantitative evidence for the potential revision or removal of items.

Results

Overall, 14 patients (female, n=10; mean [SD] age and time since diagnosis, 55.3 [15.5] and 4.3 [4.0] years, respectively) were interviewed. Concept saturation was reached after 3 rounds of CE/CIUT, with 15 of the 25 unique CIPO signs and symptoms included in the CIPO eDD (Table). Based on feedback from follow-up interviews (12 patients), no changes were made to items in the draft CIPO eDD. Minor changes were made to four items (vomiting, regurgitation, early satiety and CIPO episodes) suggested by qualitative data and the steering committee to improve clarity; the order of the nausea and vomiting items was switched. The sorting exercise did not identify any items for addition/removal or revision based on the qualitative evidence, with most patients indicating that all items should remain in the diary.

Conclusion

We have developed a de novo CIPO-specific ePRO per established FDA guidelines.^1,2 A final scoring system of the CIPO eDD based on the 15 items is in development. Ongoing quantitative assessment and psychometric validation of the CIPO eDD will enable its use in monitoring CIPO severity in clinical trials, thus supporting the development of effective therapies.

Table. Final items for the CIPO Daily Diary, and amendments from patient interviews

References

1. FDA. Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims. 2009. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/patient-reported-outcome-measures-use-medical-product-development-support-labeling-claims (Accessed April 15, 2025).
2. FDA. Patient-Focused Drug Development: Collecting Comprehensive and Representative Input. 2009. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/patient-focused-drug-development-collecting-comprehensive-and-representative-input (Accessed April 15, 2025).

Disclosure

MG has received research support from Alexza Pharmaceuticals, Alfasigma, Donga and Takeda; and is an advisory board member for Alfasigma, Ardelyx and Evoke Pharma.
ViS is an advisory board member and/or speaker for Alfasigma, Bayer, Bromatech, Falck and GE Healthcare; and receives research support from Alfasigma.
JT has given scientific advice to Aclipse, Adare Pharma Solutions, Alfasigma, Clasado, Danone, Dr Falk Pharma, FitForMe, Ironwood, Kyowa Kirin, Menarini, PRO.MED.CS, Recordati, Takeda, Truvion Healthcare, Tsumura and Zealand Pharmaceuticals; receives research support from BIOHIT Healthcare, Kyowa Kirin, ProMed, Sofar and Takeda; and is a speaker for Abbott, Biocodex, Mayoly, Menarini, ProMed, Reckitt Benckiser, Schwabe, Takeda, Thai Meiji Pharmaceutical and Truvion Healthcare.
SM, EP and VaS are employees of Alfasigma S.p.A.
This study was sponsored by Alfasigma S.p.A.
The authors would like to thank all of the Alfasigma team who were involved in this study for their contributions to study conceptualization, study design, methodology, data curation, formal analysis, data interpretation and endorsement of the study design. In addition, the authors would like to thank the external consultants for their time and expertise, and the principal investigators at the collaborating sites for patient recruitment and data collection.
Medical writing support for the development of this abstract was provided by Hannah Stephens, PhD, of PharmaGenesis London, London, UK, and was funded by Alfasigma S.p.A.