Introduction

Metastasis is the major cause of mortality among colorectal cancer (CRC) patients and represents a crucial cancer research challenge. Metastasis is the results of an intimate crosstalk between cancer cells and the surrounding tumor microenvironment, where neoplastic cells exploit the inefficient and leaky tumor vessels to disseminate to secondary organs¹. In this context, the extracellular matrix protein Multimerin-2, specifically deposited by endothelial cells (EC), is instrumental for the maintenance of vascular homeostasis, ensuring the proper formation of cell-cell junctions via the VEGFR2 signaling².

Aims & Methods

We observed that Multimerin-2 is down modulated in tumors both at transcriptional and post-translational levels. Thus we hypothesized that Multimerin-2-devoid vessels may enhance cancer cell dissemination, being characterized by a compromised endothelial barrier.
Multimerin-2 expression was analyzed in human CRC samples through IHC, ELISA and in silico by the tnmplot.com tool. The effects of Multimerin-2 loss were assessed in vitro through transmigration assays upon Multimerin-2 down-regulation in EC cells and the molecular mechanism verified by WB and qRT-PCR. The putative Multimerin-2-affected metastatic dissemination was assessed through intravenous injection of MC38 colon cancer cells in wt and Multimerin-2^-/-mice.

Results

Multimerin-2 expression is significantly reduced within the tumor tissue respect to the normal counterpart among CRC patients, despite at variable degree. Importantly, in vitro, we found an increased number of CRC cells transmigrating through a Multimerin-2-depleted endothelium. This phenomenon was not VEGFR2-dependent since the use of a VEGFA blocking agents did not affect the extravasation of tumor cells. Indeed, under tumor-mimicking conditions, the knock-down of Multimerin-2 in ECs induces the upregulation of the vascular adhesion molecule VCAM1, a molecule exploited also by cancer cells to transpass the endothelium³. Accordingly, the intravenous injection of B16F10 syngeneic melanoma cells, as well as MC38 colon cancer cells, in Multimerin-2^-/-mice led to the formation of a higher number of metastatic lesions in the lungs.

Conclusion

Overall, these data indicate that Multimerin-2 expression is required to maintain vascular stability and halt the escape of cancer cells, suggesting that the Multimerin-2-devoid tumor vessels may represent a preferential route for metastatic dissemination, during CRC progression.

References

¹ Lugano R. et al, Tumor angiogenesis: causes, consequences, challenges and opportunities, Cell Mol Life Sci., 2020
² Pellicani R. et al, Multimerin-2 Maintains Vascular Stability and Permeability, Matrix Biol., 2020
³ Wieland E. et al, Endothelial Notch1 Activity Facilitates Metastasis, Cancer Cell 2017

Clinical Case Summary

Introduction: Inflammatory bowel disease (IBD) is linked to cutaneous manifestations in 10% of cases. Neutrophilic dermatoses represent a diagnostic and management challenge, as it requires a dual-targeted treatment approach.
Clinical Case: We present a 67-year-old man with A3L1B1 Crohn’s disease (CD) followed in our IBD consultation. His medical history included previous tobacco abuse, hypertension, type 2 diabetes and ischemic cardiopathy with heart failure. He was medicated for his comorbidities and had been treated with budesonide.
Due to evidence of disease progression, increased fecal calprotectin (FC) at 751ug/g and a history of invasive pulmonary aspergillosis, vedolizumab was initiated.
The patient presented with recurrent erythematous, tender, nodular lesions on the abdomen, limbs and face. Dermatological consultation and cutaneous biopsies led to an initial misdiagnosis of infectious panniculitis, as methicillin sensitive Staphylococcus aureus (MSSA) was isolated and the lesions regressed with antibiotics.
Two months later, cutaneous lesions reappeared and histopathology confirmed IBD-associated erythema nodosum-like neutrophilic dermatosis with MSSA isolation. A 10-week doxycycline course induced their regression. However, recurrence transpired 5 months later, associated with an increased FC (816ug/g).
A swap for ustekinumab (UST) resulted only in transient clinical and biochemical improvement (FC 324ug/g). Despite dose escalation to every 4 weeks, nodular/papular lesions with central postulation recently reappeared, prompting initiation of daptomycin with a potential swap to another drug class.
Conclusions: IBD can be associated with neutrophilic dermatoses and its diagnosis can be challenging. This case reports an CD-associated erythema nodosum-like neutrophilic dermatosis, underscoring its complex approach and management.
Note: We are submitting this case with iconography as it underscores a rare IBD manifestation.

References

Photographs of cutaneous lesions (3-4)

Clinical Case Summary

Introduction: Ustekinumab (UST), a human interleukin-12/23 monoclonal antibody, is approved for the treatment of moderate to severe Crohn’s disease (CD) and ulcerative colitis (UC). Some patients may lose response to standard maintenance therapy. Optimization strategies, such as dose escalation and intravenous (IV) re-induction, have been explored in CD, but scarcely studied in UC.
Clinical Case: A 61-year-old woman, with grade III obesity, hypertension, and peripheral venous insufficiency, diagnosed with UC and associated peripheral arthropathy, was initially treated with high-dose corticosteroids (CTS) for a severe exacerbation. She developed CTS dependence and suffered an osteoporotic fracture.
A combined therapy with methotrexate and an accelerated infliximab (IFX) induction regimen was initiated, but a severe exacerbation occurred after the second induction dose. Despite an early third dose, clinical, biochemical and endoscopic (Mayo score 3) activity persisted.
The patient was swapped to UST with maintenance therapy every 4 weeks. After IV infusion, free-CTS clinical and biochemical (fecal calprotectin (FC) <10 ug/g) remission were achieved, but, over time, there was a loss of response, with a FC 4817 ug/g.
Given the initial positive response to IV UST infusion and insights from CD studies, a 520mg IV UST re-induction followed by 4-week maintenance dose was administered. Eight months later, the patient remains in free-CTS clinical remission, with improved arthralgia, biochemical remission (FC 80 ug/g) and endoscopic response.
Conclusions: This case highlights the potential efficacy of IV UST re-induction in recapturing remission in refractory UC. While recognized in CD, UST re-induction may prove beneficial for UC patients with loss of response to standard UST therapy, serving as an alternative before swapping. Further exploration through randomized, multicenter studies is crucial to assess the efficacy and safety of this strategy in UC patients.

Introduction

The incidence of early-onset colorectal cancer is increasing alarmingly worldwide, and countermeasures against this issue are urgently needed. Although previous studies suggested age-related molecular pathological changes, the association between the roles of Immunosocore using the ration of CD3+ and CD8+ T cells in anti-tumor immune responses and early-onset colorectal cancer and adenoma resected by endoscopy remains unclear. This study aimed to investigate the association of Immunosocore using the ratio of CD3+ and CD8+ T cells and clinicopathological characteristics mainly focused on early-onset tumors. We defined early-onset colorectal tumors as those that occurred at less than 50 years of age at diagnosis and later-onset as those that occurred at 50 years of age or older in this study.

Aims & Methods

The aim of this study was to investigate the association between Immunosocore and clinicopathological features of early-onset colorectal tumors. Utilizing a molecular pathological database of 169 colorectal cancer and adenoma cases, we analyzed 306 colorectal lesions including 214 early-onset tumors resected by endoscopic procedures including cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection from February 2017 to January 2020 at Nippon Medical School Hospital in Japan. After collecting formalin-fixed paraffin-embedded (FFPE) tissue blocks, CD3 and CD8 immunostaining was performed, and the number of CD3+ and CD8+ cells was quantified in each area of tumor, stromal, and normal. One to five fields of view (median 5 fields) were selected depending on the size of the lesion using a fluorescence microscope BZ-X800 (KEYENCE) at 200x magnification, and the average number of CD3+ and CD8+ cells was calculated by automatic counting. Counting stromal and normal cells was limited to those specimens for which the excised specimens were large enough to contain sufficient stromal and normal portions in addition to the tumor portion. Immunoscore was calculated by the ratio of CD8+/CD3+ positive T cells. Clinicopathologic characteristics were also evaluated retrospectively. Chi-square test was used to compare categorical variables, Spearman's test to examine correlation, Mann-Whitney U test to compare continuous variables, and Kruskal-Wallis test to compare the three groups.

Results

The tumor location was 126 (41%)/142 (47%)/37 (12%) in the proximal/ distal colon/rectum. The number of CD3+T cells decreased significantly with increasing tumor diameter (P<0.001). The number of CD3+T cells was predominantly lower in type Ip (protruding type) compared to type non-Ip (P<0.001). The distribution of Immunoscore measured in tumor area was significantly different among tumor locations (P<0.05).

Conclusion

Using endoscopically resected specimens, we suggest that the anti-tumor immune response may differ according to tumor size, gross type, and location. Further studies are warranted to stratify early-onset tumors requiring careful surveillance after endoscopic resection in terms of the anti-tumor immune response in T cells.

Introduction

Colorectal endoscopic submucosal dissection (ESD) is spreading worldwide, with increasing demand for training. Standardized skills assessment has yet to be defined to guarantee the quality and safety of the results obtained by trainees during their learning curve. ESGE recommends that the first ESD procedures should be supervised by an ESD-proficient endoscopist. The impact of a trainee's active participation on these initial supervised ESD results should be addressed.

Aims & Methods

Between 01/2017 and 01/2024, all consecutive colorectal ESD procedures were prospectively registered by 3 participating ESD training centers, and data were analyzed retrospectively. Trainee participation was tracked. A trainee was defined as having performed less than 50 ESD’s on humans, alone or under supervision. We compared the main procedural outcomes with respect to the presence or absence of a trainee involved in the colorectal ESD procedure. Multivariate analysis and propensity score matching (PSM) were performed.

Results

2462 consecutive colorectal ESD were included, of which 543 procedures (22%) involved the active participation of a trainee (15 trainers/15 trainees). Rectal lesions were more often treated with participation of a trainee (56% vs 31%, p<0.001 with-trainee vs trainer-alone respectively). There was no significant difference in en-bloc, R0 and curative resection rates whether a trainee participated or not (95.8%, 85.9% and 84.9% vs 95.1%, 88.2% and 84.7%, with-trainee vs trainer-alone respectively). Participation of a trainee resulted in a significant decrease in dissection speed (29.4 mm²/min vs 43.9 mm²/min, p<0.001 with-trainee vs trainer-alone respectively). Rates of perforation, delayed bleeding and surgery for complications were 8.6%, 5.9% and 0.9% vs 9%, 4.5% and 0.7% for with-trainee vs trainer-alone respectively, without significant differences. After PSM, the presence of a trainee significantly decreased the dissection speed (29.4 mm²/min vs 42.7 mm²/min, p<0.001 with-trainee vs trainer-alone respectively), increased the perforation rate (8.7% vs 5%, p=0.023 with-trainee vs trainer-alone respectively), but did not influence the curative resection rate (84.9% vs 88.8%, p=0.078 with-trainee vs trainer-alone respectively).

Conclusion

Active participation of a trainee during colorectal ESD did not affect the curative resection rate. However slower dissection speed and higher perforation rates, without increasing the need for surgery, were observed.

Disclosure

Nothing to disclose

Introduction

Diagnosing and assessing Inflammatory Bowel Disease (IBD) requires invasive procedures such as endoscopy and intestinal biopsies. However, reliable and accurate non-invasive tools for assessing and monitoring inflammation in IBD patients are in an exciting phase of early development. Raman spectroscopy (RS), which provides molecular vibrational spectra, can characterise human biofluids and intestinal samples, offering the potential for non-invasive molecular assessment, characterisation and monitoring in IBD.

Aims & Methods

This study aims to explore the potential of RS applied to saliva, blood and intestinal biopsies from IBD patients for molecular characterisation and development of new biomarkers enabling a reliable and accurate non-invasive diagnosis of IBD, phenotyping between Crohn’s disease (CD) and Ulcerative Colitis (UC) and predicting mucosal healing (MH). IBD patients undergoing advanced endoscopy, i.e. ultra-high magnification endocytoscopy or probe-based confocal laser endomicroscopy, for disease assessment or surveillance and healthy controls were prospectively enrolled from two university hospitals in Cork, Ireland. Peripheral blood, saliva, and biopsies from the most representative bowel areas were collected. All matching samples were processed through a novel waveguide-enhanced RS technique, enabling sensitive detection of metabolites and other biochemical components. Additionally, MH from matching biopsies was assessed as RHI≤3 without lamina propria or epithelial neutrophils, NHI ≤1 and PHRI=0. RS data processing was performed using Matlab®. Spectral markers matched for saliva, blood and biopsies and differentiating IBD vs controls, CD vs UC and MH vs active inflammation were identified. A machine learning model based on linear discrimination analysis was used to assess the classification accuracy.

Results

A cohort of 16 IBD patients (median age 39, 11:5 M: F), comprising 9 UC and 7 CD, and 4 healthy controls (median age 43.5, 3:1 M: F) was enrolled, with matching saliva, blood, and biopsies. MH was found in 4 IBD patients. When comparing IBD patients with controls, differences in 3 wavenumbers were observed in all samples, corresponding to decreased tyrosine and lipids signals and increased carotenoids signal in IBD. Similarly, differences in spectral markers were found in CD vs UC, with increased lipids signal in CD and increased signals for carotenoids, nucleic acid, and amide proteins in UC. Interestingly, 5 matching differences in saliva, plasma and biopsies spectra were found in patients with MH compared to those with active inflammation, including an increase in nucleic acids and amide proteins and a decrease in phosphate, lipids, and carotenoids. The machine learning model showed promising accuracy (above 82%) of RS-aided biofluids analysis in diagnosing IBD and predicting phenotype and MH.

Conclusion

The combination of spectral markers from saliva and plasma, confirmed at tissue level, showed promise in accurately diagnosing IBD and distinguishing CD from UC. Notably, RS non-invasive biomarkers could predict MH with promising accuracy, identifying metabolites involved in IBD-associated inflammation, particularly lipids, carotenoids, and nucleic acids. Therefore, RS holds potential as a monitoring and predictive tool for inflammation and healing in IBD, with intriguing translational implications. Further studies are required to validate these preliminary findings and shed light on molecular mechanisms.