The Risk of Colectomy and Colorectal Cancer After Appendectomy in Patients With Ulcerative Colitis: A Systematic Review and Meta-analysis

Contrast-Enhanced Ultrasound-Guided Endoscopic Retrograde Appendicitis Treatment-A Pilot Study on the Diagnostic and Therapeutic Efficacy in Uncomplicated Appendicitis

OBJECTIVE

To determine the diagnostic and therapeutic value of contrast-enhanced ultrasound-guided endoscopic retrograde appendicitis treatment (ERAT) in patients with uncomplicated appendicitis.

METHODS

A retrospective analysis was performed on clinical and ultrasound data collected from 105 pediatric patients with uncomplicated appendicitis between January 2020 and December 2023. The ultrasound findings before and after treatment, as well as postoperative follow-up and recurrence rates, were summarized and analyzed.

RESULTS

Successful intubation was achieved in 96 patients (91.4%). The conventional ultrasound appendix visualization rate was 39.6% (38/105), while the appendix visualization rate after contrast-enhanced ultrasound-guidance was 75% (72/105). Contrast-enhanced ultrasound revealed various appendiceal morphologic changes in 89 patients, such as twisting, tortuosity, stiffness, rough inner wall, dilated diameter, and narrowing of the lumen. Additionally, local filling defects, which indicated the presence of fecal stones or debris deposition, were noted in 68 patients. No leakage of the contrast agent occurred. Post-treatment evaluation showed improvement in appendiceal diameter, lumen, and filling defects (P < .01). The follow-up rate was 82 of 89 patients (92.1%), all of whom recovered well without a recurrence. The recurrence rate was 7.9% (7/89). Among the patients with recurrences, five patients resolved after medical treatment and two patients recovered after surgical treatment.

CONCLUSION

Contrast-enhanced ultrasound-guided ERAT for uncomplicated appendicitis is safe and effective. Specifically, the appendix is increased, which facilitates an evaluation of therapeutic effectiveness. ERAT serves as a valuable supplementary modality to determine the need for surgical treatment of acute appendicitis, which is of significant clinical value.

Appendectomy and Risk of Advanced Colorectal Neoplasia in Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study

BACKGROUND

The aim of this study was to examine the association between appendectomy and advanced colorectal neoplasia (aCRN) in patients with inflammatory bowel disease (IBD).

METHODS

Inflammatory bowel disease patients diagnosed in Denmark in the period 1977 to 2017 were identified from the Danish National Patient Registry. Inflammatory bowel disease patients who underwent appendectomy were matched with up to 10 IBD patients without appendectomy and followed until aCRN, death, or emigration. Absolute risks of aCRN were calculated, treating death and bowel resections as competing risks. Stratified Cox regression was used to calculate adjusted hazard ratios (aHRs) of aCRN, comparing IBD patients with appendectomy to IBD patients without appendectomy.

RESULTS

We identified 3789 IBD patients with appendectomy and 37 676 IBD patients without appendectomy. A total of 573 patients (1.4%) developed aCRN, with an absolute risk of aCRN at 20 years of 4.9% (95% confidence interval [CI], 2.9%-7.7%) for ulcerative colitis (UC) patients with appendectomy after UC diagnosis compared with 2.8% (95% CI, 2.3%-3.3%) for UC patients without appendectomy. Appendectomy after UC was associated with an increased rate of aCRN 5 to 10 years (aHR, 2.5; 95% CI, 1.1-5.5) and 10 to 20 years after appendectomy (aHR, 2.3; 95% CI, 1.0-5.5). Appendectomy prior to UC diagnosis was not associated with an increased rate of aCRN, and Crohn's disease was not associated with the rate of aCRN, regardless of timing or histological diagnosis of the appendix specimen.

CONCLUSIONS

Although appendectomy may have a positive effect on the clinical course of UC, our study suggests that this may come at the expense of a higher risk of aCRN.

Indications, modalities, and outcomes of surgery for ulcerative colitis in 2024

Treatment of ulcerative colitis (UC) has been revolutionized by the arrival of biotherapies and technical progress in interventional endoscopy and surgery. (Sub)total emergency colectomy is required in the event of complicated severe acute colitis: colectasis, perforation, hemorrhage, organ failure. Corticosteroid therapy is the reference treatment for uncomplicated severe acute colitis, while infliximab and ciclosporin are 2nd-line treatments. At each step, before and after each line of treatment failure, surgery should be considered as an option. In cases refractory to medical treatment, the choice between surgery and change in medication must weigh the chronic symptoms associated with the disease against the risks of postoperative complications and functional sequelae inherent to surgery. Detection of dysplastic lesions necessitates chromoendoscopic imaging with multiple biopsies and anatomopathological verification. Endoscopic treatment of these lesions remains reserved for selected patients. These different indications call for multidisciplinary medical-surgical discussion. Total coloproctectomy with ileo-anal anastomosis (TCP-IAA) is the standard surgery, and it holds out hope for healing. Modalities depend on patient characteristics, previous emergency colectomy, and presence of dysplasia. It may be carried out in one, in two modified, or in three phases. The main complications are anastomotic fistula, short-term pouch-related fistula, ileo-anal pouch syndrome, pouchitis and long-term digestive and sexual disorders. For selected cases, an alternative can consist in total colectomy with ileo-rectal anastomosis or permanent terminal ileostomy. The objective of this update is to clarify the indications, modalities, and results of surgical treatment of ulcerative colitis in accordance with the most recent data in the literature.

Clinical statistical analysis plan for the ACCURE trial: the effect of appendectomy on the clinical course of ulcerative colitis, a randomised international multicentre trial

BACKGROUND

The primary treatment of ulcerative colitis (UC) is medical therapy using a standard step-up approach. An appendectomy might modulate the clinical course of UC, decreasing the incidence of relapses and reducing need for medication. The objective of the ACCURE trial is to assess the efficacy of laparoscopic appendectomy in addition to standard medical treatment in maintaining remission in UC patients. This article presents the statistical analysis plan to evaluate the outcomes of the ACCURE trial.

DESIGN AND METHODS

The ACCURE trial was designed as a multicentre, randomised controlled trial. UC patients with a new diagnosis or a disease relapse within the past 12 months, treated with 5-ASA, corticosteroids, or immunomodulators until complete clinical and endoscopic remission (defined as total Mayo score < 3 with endoscopic subscore of 0 or 1), were counselled for inclusion. Also, patients previously treated with biologicals who had a washout period of at least 3 months were considered for inclusion. Patients were randomised (1:1) to laparoscopic appendectomy plus maintenance treatment or a control group (maintenance therapy only). The primary outcome is the 1-year UC relapse rate (defined as a total Mayo-score ≥ 5 with endoscopic subscore of 2 or 3, or clinically as an exacerbation of symptoms and rectal bleeding or FCP > 150 or intensified medical therapy other than 5-ASA therapy). Secondary outcomes include number of relapses per patient, time to first relapse, disease activity, number of colectomies, medication usage, and health-related quality of life.

DISCUSSION

The ACCURE trial will provide comprehensive evidence whether adding an appendectomy to maintenance treatment is superior to maintenance treatment only in maintaining remission in UC patients.

TRIAL REGISTRATION

Dutch Trial Register (NTR) NTR2883 . Registered May 3, 2011. ISRCTN, ISRCTN60945764 . Registered August 12, 2019.

Epigenetic regulation and therapeutic strategies in ulcerative colitis

Ulcerative colitis (UC) is an inflammatory bowel disease, and is characterized by the diffuse inflammation and ulceration in the colon and rectum mucosa, even extending to the caecum. Epigenetic modifications, including DNA methylations, histone modifications and non-coding RNAs, are implicated in the differentiation, maturation, and functional modulation of multiple immune and non-immune cell types, and are influenced and altered in various chronic inflammatory diseases, including UC. Here we review the relevant studies revealing the differential epigenetic features in UC, and summarize the current knowledge about the immunopathogenesis of UC through epigenetic regulation and inflammatory signaling networks, regarding DNA methylation, histone modification, miRNAs and lncRNAs. We also discuss the epigenetic-associated therapeutic strategies for the alleviation and treatment of UC, which will provide insights to intervene in the immunopathological process of UC in view of epigenetic regulation.

The appendix and ulcerative colitis - an unsolved connection

The appendix is thought to have a role in the pathogenesis of ulcerative colitis, but the nature and basis of this association remains unclear. In this Perspective, we consider the biology of the appendix with respect to its immunological function and the microbiome, and how this relates to evidence that supports the involvement of the appendix in ulcerative colitis. In experimental models, removal of the inflamed appendix prevents colitis, and in human observational studies, appendectomy is associated with protection against ulcerative colitis. Further, among people who develop ulcerative colitis, appendectomy before diagnosis might influence the course and outcomes of the disease - some evidence suggests that it protects against colectomy but could increase the risk of colorectal cancer. Appendectomy after onset of ulcerative colitis seems to have disparate consequences. Clinical trials to understand whether appendectomy has a role in the treatment of ulcerative colitis are ongoing. Major questions about the role of the appendix in the pathogenesis of ulcerative colitis remain unanswered, and further research is needed to establish whether the connection is clinically relevant.

Optimizing individualized management of patients with ulcerative colitis: Identification of risk factors predicting ulcerative colitis-associated neoplasia

The risk of developing colorectal neoplasia in patients with ulcerative colitis (UC) is increased. The purpose of this study is to analyze the risk factors of UC-associated neoplasia (UCAN) in UC patients and establish a clinical prediction model. 828 UC patients were included in this retrospective study. 602 patients were in discovery cohort and 226 patients were in validation cohort (internal validation cohort/external validation cohort: 120/106). Clinical and endoscopic data were collected. The discovery cohort was divided into UC group and UCAN group for univariate and multivariate binary logistic analyses. The UCAN clinical prediction model was established and verified. In the univariate analysis, 7 risk factors were related to UCAN. Multivariate logistic regression analysis showed that age at diagnosis of UC (OR: 1.018, 95% CI: 1.003-1.033), Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score (OR: 1.823, 95% CI: 1.562-2.128), and size of polyps (size1: OR: 6.297, 95% CI: 3.669-10.809; size2: OR: 12.014, 95% CI: 6.327-22.814) were independent risk factors of UCAN. A mathematical equation was established. The area under the ROC curve (AUC) of this model was calculated to be 0.845 (95%CI: 0.809-0.881). The sensitivity was 0.884 and the specificity was 0.688. The AUC of internal validation cohort was 0.901 (95%CI: 0.815, 0.988), sensitivity was 75.0% and specificity was 92.6%. The AUC of external validation cohort was 0.842 (95%CI: 0.709, 0.976), sensitivity was 62.5% and specificity was 93.9%. This prediction model is simple, practical, and effective for predicting the risk of UCAN, which is beneficial to the individualized management of patients with UC.

Appendicitis is associated with an increased risk of systemic lupus erythematosus: a nationwide, population-based, case-control study

OBJECTIVE

To examine the association between appendicitis and the risk of systemic lupus erythematosus (SLE).

METHODS

Using claims data from the 2003-2013 Taiwanese National Health Insurance Research Database, we selected 6054 patients with newly diagnosed SLE from 2007 to 2012 and 36,324 age-, sex- and year of SLE diagnosis date-matched (1:6) non-SLE controls. After controlling for potential confounders, a multivariable conditional logistic regression model was used to calculate the adjusted odds ratio (aOR) with 95% confidence interval (CI) for the association of appendicitis history with SLE. Sensitivity analyses were conducted using various definitions of appendicitis. Subgroup analyses were conducted to examine possible modification effects by age, gender, level of urbanization, income and Charlson Comorbidity Index (CCI).

RESULTS

The average age of patients was 38 years old in both groups. The proportion of females was 86.5%. 75 (1.2%) of SLE cases and 205 (0.6%) of non-SLE controls had appendicitis history before the index date. After adjusting for potential confounding factors, appendicitis was associated with a higher risk of SLE (aOR, 1.84; 95% CI, 1.34-2.52), and such association remained robust after variation of appendicitis definition. No significant modification effects were found for the association between appendicitis and SLE by age, gender, urbanization level, income and CCI.

CONCLUSION

This nationwide, population-based case-control study demonstrates an association between appendicitis and incident SLE. Lack of individual smoking status is a major limitation. Key Points • Appendicitis was significantly associated with an increased risk of SLE. • Such association remained robust using various definitions of appendicitis.

Risk of colorectal cancer after appendectomy: A systematic review and meta-analysis

BACKGROUND AND AIM

Appendectomy is associated with various diseases, but whether it increases the risk of colorectal cancer (CRC) remains uncertain. We conducted a systematic review and meta-analysis aimed at investigating the suggested correlation between appendectomy and CRC.

METHODS

Systematic retrieval was performed using the PubMed, Embase, Cochrane library, Web of Science, and ClinicalTrials.gov databases up to May 4, 2022, for studies reported the influence of appendectomy on CRC, colon cancer (CC) or rectal cancer (RC). Odd ratios (ORs) and 95% confidence intervals (CIs) of CRC after appendectomy were pooled using the random effects model. Subgroup analyses were carried on by region, sex, and tumor location.

RESULTS

Our search identified 1743 articles, of which 22 studies from three continents published between 1964 and 2022 were eligible for inclusion. Overall, people with appendectomy had a higher risk of CRC (OR = 1.31; 95% CI [1.05, 1.62]). But the risk for Europeans was not significant (OR = 0.94; 95% CI [0.87, 1.02]; I²  = 0%), while for Americans and Asians, appendectomy would increase the risk of CRC (OR = 1.68; 95% CI [1.15, 2.44]; I²  = 65% and OR = 1.46; 95% CI [1.04, 2.05]; I²  = 98%), especially in females and in developing countries. It is worth noting that appendectomy might be a protective factor for CC in European women (OR = 0.87; 95% CI [0.77, 0.98]; I²  = 0%).

CONCLUSIONS

Appendectomy may be a risk factor for CRC, with varying degrees in different populations. More high-quality cross-regional studies are needed for better clinical decision making.

Issues for patchy tissues: defining roles for gut-associated lymphoid tissue in neurodevelopment and disease

Individuals diagnosed with neurodevelopmental conditions such as autism spectrum disorder (ASD; autism) often experience tissue inflammation as well as gastrointestinal dysfunction, yet their underlying causes remain poorly characterised. Notably, the largest components of the body's immune system, including gut-associated lymphoid tissue (GALT), lie within the gastrointestinal tract. A major constituent of GALT in humans comprises secretory lymphoid aggregates known as Peyer's patches that sense and combat constant exposure to pathogens and infectious agents. Essential to the functions of Peyer's patches is its communication with the enteric nervous system (ENS), an intrinsic neural network that regulates gastrointestinal function. Crosstalk between these tissues contribute to the microbiota-gut-brain axis that altogether influences mood and behaviour. Increasing evidence further points to a critical role for this signalling axis in neurodevelopmental homeostasis and disease. Notably, while the neuroimmunomodulatory functions for Peyer's patches are increasingly better understood, functions for tissues of analogous function, such as caecal patches, remain less well characterised. Here, we compare the structure, function and development of Peyer's patches, as well as caecal and appendix patches in humans and model organisms including mice to highlight the roles for these essential tissues in health and disease. We propose that perturbations to GALT function may underlie inflammatory disorders and gastrointestinal dysfunction in neurodevelopmental conditions such as autism.

The Appendix Orchestrates T-Cell Mediated Immunosurveillance in Colitis-Associated Cancer

BACKGROUND & AIMS

Although appendectomy may reduce colorectal inflammation in patients with ulcerative colitis (UC), this surgical procedure has been suggested to be associated with an increased risk of colitis-associated cancer (CAC). Our aim was to explore the mechanism underlying the appendectomy-associated increased risk of CAC.

METHODS

Five-week-old male BALB/c mice underwent appendectomy, appendicitis induction, or sham laparotomy. They were then exposed to azoxymethane/dextran sodium sulfate (AOM/DSS) to induce CAC. Mice were killed 12 weeks later, and colons were taken for pathological analysis and immunohistochemistry (CD3 and CD8 staining). Human colonic tumors from 21 patients with UC who underwent surgical resection for CAC were immunophenotyped and stratified according to appendectomy status.

RESULTS

Whereas appendectomy significantly reduced colitis severity and increased CAC number, appendicitis induction without appendectomy led to opposite results. Intratumor CD3+ and CD8+ T-cell densities were lower after appendectomy and higher after appendicitis induction compared with the sham laparotomy group. Blocking lymphocyte trafficking to the colon with the anti-α4β7 integrin antibody or a sphingosine-1-phosphate receptor agonist suppressed the inducing effect of the appendectomy on tumors' number and on CD3+/CD8+ intratumoral density. CD8+ or CD3+ T cells isolated from inflammatory neo-appendix and intravenously injected into AOM/DSS-treated recipient mice increased CD3+/CD8+ T-cell tumor infiltration and decreased tumor number. In UC patients with a history of appendectomy, intratumor CD3+ and CD8+ T-cell densities were decreased compared with UC patients without history of appendectomy.

CONCLUSIONS

In UC, appendectomy could suppress a major site of T-cell priming, resulting in a less efficient CAC immunosurveillance.

The Role of Appendicectomy in Ulcerative Colitis: Systematic Review and Meta-Analysis

BACKGROUND

This updated systematic review and meta-analysis investigates the putative role of the appendix in ulcerative colitis as a therapeutic target.

METHODS

Ovid Medline, Embase, PubMed and CENTRAL were searched with MeSH terms ("appendectomy" OR "appendicitis" OR "appendix") AND ("colitis, ulcerative") through October 2020, producing 1469 references. Thirty studies, including 118 733 patients, were included for qualitative synthesis and 11 for quantitative synthesis. Subgroup analysis was performed on timing of appendicectomy. Results are expressed as odds ratio (OR) with 95% confidence intervals (CIs).

RESULTS

Appendicectomy before UC diagnosis reduces the risk of future colectomy (OR, 0.76; 95% CI, 0.65-0.89; I2 = 5%; P = .0009). Corresponding increased risk of colorectal cancer and high-grade dysplasia are identified (OR, 2.27; 95% CI, 1.11-4.66; P = .02). Significance is lost when appendicectomy is performed after disease onset. Appendicectomy does not affect hospital admission rates (OR, 0.87; 95% CI, 0.68-1.12; I2 = 93%; P = .27), steroid use (OR, 1.08; 95% CI, 0.78-1.49; I2 = 36%; P = .64), immunomodulator use (OR, 1.04; 95% CI, 0.76-1.42; I2 = 19%; P = .79), or biological therapy use (OR, 0.76; 95% CI, 0.44-1.30; I2 = 0%; P = .32). Disease extent and risk of proximal progression are unaffected by appendicectomy. The majority (71% to 100%) of patients with refractory UC avoid colectomy following therapeutic appendicectomy at 3-year follow-up.

CONCLUSIONS

Prior appendicectomy reduces risk of future colectomy. A reciprocal increased risk of CRC/HGD may be due to prolonged exposure to subclinical colonic inflammation. The results warrant further research, as consideration may be put toward incorporating a history of appendicectomy into IBD surveillance guidelines. A potential role for therapeutic appendicectomy in refractory left-sided UC is also identified.

Procyanidin A1 alleviates DSS-induced ulcerative colitis via regulating AMPK/mTOR/p70S6K-mediated autophagy

Ulcerative colitis (UC) is a recurrent chronic inflammatory disease. The symptom of UC is mainly diarrhea including bloody stools. Increasing evidence has suggested that procyanidin A1 (PCA1) exerts an anti-inflammatory effect in several diseases. However, the role of PCA1 in UC is still a mystery. In our study, we explored the effect of PCA1 in dextran sulfate sodium (DSS)-induced UC mice and lipopolysaccharide (LPS)-stimulated HT-29 and IEC-6 cells. Then, cell proliferation, apoptosis, the production of proinflammatory cytokines, and autophagy-related markers were determined. Furthermore, the AMPK/mTOR/p70S6K signaling pathway was assayed by Western blot assay. In in vivo study, we found that PCA1 administration alleviated DSS-induced UC, as evidenced by reducing weight loss, clinical scores, colon weight/length ratio, histological damage, proinflammatory cytokines, and apoptosis. Moreover, we showed that the expression of Beclin-1 and LC3II/I ratio was increased, whereas the level of p62 was decreased after PCA1 treatment in vivo. Meanwhile, the reduced AMP/ATP ratio, enhanced expression of p-AMPK, and decreased p-p70S6K and p-mTOR levels indicate the activation of AMPK/mTOR/p70S6K signaling pathway. In in vitro study, PCA1 promoted cell proliferation and inhibited cell apoptosis in LPS-stimulated HT-29 and IEC-6 cells. Pro-inflammatory cytokines and autophagy-related factors exhibited the same trend as in in vivo results. Mechanically, PCA1 activated the AMPK/mTOR/p70S6K signaling pathway. The treatment with an AMPK inhibitor compound C significantly reversed the anti-inflammatory effect of PCA1 in LPS-stimulated cells. Taken together, these data indicated that PCA1 alleviated UC through induction of AMPK/mTOR/p70S6K-mediated autophagy.

Inflammatory Bowel Disease-Associated Colorectal Cancer: Translational Risks from Mechanisms to Medicines

The cumulative impact of chronic inflammation in patients with inflammatory bowel diseases predisposes to the development of inflammatory bowel disease-associated colorectal cancer [IBD-CRC]. Inflammation can induce mutagenesis, and the relapsing-remitting nature of this inflammation, together with epithelial regeneration, may exert selective pressure accelerating carcinogenesis. The molecular pathogenesis of IBD-CRC, termed the 'inflammation-dysplasia-carcinoma' sequence, is well described. However, the immunopathogenesis of IBD-CRC is less well understood. The impact of novel immunosuppressive therapies, which aim to achieve deep remission, is mostly unknown. Therefore, this timely review summarizes the clinical context of IBD-CRC, outlines the molecular and immunological basis of disease pathogenesis, and considers the impact of novel biological therapies.

The cecal appendix is correlated with greater maximal longevity in mammals

The cecal appendix had been considered as a useless vestige since Darwin's work, but recent research questioned this idea demonstrating that the cecal appendix appeared among the mammals at least 80 million years ago and has made multiple and independent appearances without any obvious correlation with diet, social life, ecology, or size of the cecum. However, functions and probable selective advantage conferred by this anatomical structure still remain enigmatic. We found, through analyses of data on 258 mammalian species, that cecal appendix presence is correlated with increased maximal observed longevity. This is the first demonstration of a correlation between cecal appendix presence and life history. Interestingly, the classical evolutionary theory of aging that predicts an increased longevity when the extrinsic mortality is reduced has been questioned several times, but recent comparative studies asserted its validity in the taxa, which experience age-dependent and density-dependent mortality, as in mammals. Thus, the cecal appendix may contribute to the increase in longevity through a reduction of extrinsic mortality. A lower risk of fatal infectious diarrhea is one of the most plausible hypotheses that could explain it. However, several hypotheses coexist about the possible functions of the cecal appendix, and our results provide new insights about this much-disputed question. In addition, we show that the cecal appendix arose at least 16 times and was lost only once during the evolutionary history of the considered mammals, an asymmetry that supports the existence of a positive selective of this structure.

Long-term effects of appendectomy in humans: is it the optimal management of appendicitis?

INTRODUCTION

Appendectomy remains the gold standard for treating uncomplicated and complicated appendicitis. However, the vermiform appendix may play a significant role in the immune system (secondary immune function) and maintain a reservoir of the normal microbiome for the human body. The aim of this study was to summarize the long-term effects after appendectomy and discuss whether appendectomy is suitable for all appendicitis patients.

AREAS COVERED

A comprehensive and unbiased literature search was performed in PubMed. The terms 'appendix,' 'appendicitis,' 'appendectomy,' and 'endoscopic retrograde appendicitis therapy' were searched in the title and/or abstract. This review summarizes the long-term effects of appendectomy on some diseases in humans and describes three methods including appendectomy, medical treatment, and an 'organ-sparing' technique, named endoscopic retrograde appendicitis therapy (ERAT) to treat appendicitis.

EXPERT OPINION

Appendectomy remains the first-line therapy for appendicitis. The patient's problem is appendix, not appendicitis. If we treat appendicitis, the problem should be resolved. During COVID-19, an initial antibiotic treatment of mild appendicitis represents a promising strategy. For patients who are worried about the long-term adverse effect after appendectomy and have a strong desire to preserve the appendix and are aware of the risk of appendicitis recurrence, medical treatment, or ERAT could be proposed.

ABIN3 Negatively Regulates Necroptosis-induced Intestinal Inflammation Through Recruiting A20 and Restricting the Ubiquitination of RIPK3 in Inflammatory Bowel Disease

BACKGROUND AND AIMS

There is evidence for a disturbed necroptosis function in many inflammatory diseases, but its role in inflammatory bowel diseases [IBD] and the underlying mechanisms are unclear. Here, we studied the functional significance and molecular mechanisms of ABIN3, a ubiquitin-binding protein, in regulating the ubiquitination and activation of necroptosis in IBD.

METHODS

The expression of necroptosis hallmarks and ABIN3 were assessed in inflamed samples of IBD patients, dextran sodium sulphate [DSS]-induced colitis models, and azoxymethane [AOM]/DSS models in mice. ABIN3 was overexpressed and silenced to explore its function in regulating necroptosis, inflammation, and intestinal barrier function. Immuoprecipitiation [IP] and co-IP assays were performed to investigate the cross-talk between ABIN3 and deubiquitinating enzyme A20, and the mechanisms of coordinating ubiquitination modification to regulate necroptosis.

RESULTS

Excessive necroptosis is an important contributory factor towards the uncontrolled inflammation and intestinal barrier defects in IBD and experimental colitis. Blocking necroptosis by Nec-1s or GSK'872 significantly prevented cell death and alleviated DSS-induced colitis in vivo, whereas in the AOM/DSS model, necroptosis inhibitors aggravated the severity of colitis-associated colon carcinogenesis [CAC]. Mechanistically, ABIN3 is rapidly recruited to the TNF-RSC complex, which interacts and coordinates with deubiquitinating enzyme A20 to control the K63 deubiquitination modification and subsequent activation of the critical necroptosis kinase, RIPK3, to suppress necroptosis.

CONCLUSIONS

ABIN3 regulates inflammatory response and intestinal barrier function by interacting with A20 and coordinating the K63 deubiquitination modification of necroptosis in IBD.

A nationwide database study on colectomy and colorectal cancer in ulcerative colitis: what is the role of appendectomy?

AIM

Although has been suggested that an appendectomy has a positive effect on the disease course in patients with ulcerative colitis (UC), recent studies indicate a potential increase in risk of colectomy and colorectal cancer (CRC). This study aimed to evaluate the rates of colectomy and CRC after appendectomy in UC patients using a nationwide prospective database [the Initiative on Crohn and Colitis Parelsnoer Institute - Inflammatory Bowel Disease (ICC PSI-IBD) database].

METHOD

All UC patients were retrieved from the ICC PSI-IBD database between January 2007 and May 2018. Primary outcomes were colectomy and CRC. Outcomes were compared in patients with and without appendectomy, with a separate analysis for timing of appendectomy (before or after UC diagnosis).

RESULTS

A total of 826 UC patients (54.7% female; median age 46 years, range 18-89 years) were included. Sixty-three (7.6%) patients had previously undergone appendectomy: 24 (38.1%) before and 33 (52.4%) after their diagnosis of UC. In multivariate analysis, appendectomy after UC diagnosis was associated with a significantly lower colectomy rate compared with no appendectomy [hazard ratio (HR) 0.16, 95% C: 0.04-0.66, P = 0.011], and the same nonsignificant trend was seen in patients with an appendectomy before UC diagnosis (HR 0.35, 95% CI 0.08-1.41, P = 0.138). Appendectomy was associated with delayed colectomy, particularly when it was performed after diagnosis of UC (P = 0.009). No significant differences were found in the CRC rate between patients with and without appendectomy (1.6% vs 1.2%; P = 0.555).

CONCLUSION

Appendectomy in established UC is associated with an 84% decreased risk of colectomy and a delay in surgery. Since the colon is in situ for longer, the risk of developing CRC remains, which underscores the importance of endoscopic surveillance programmes.

A link between appendectomy and gastrointestinal cancers: a large-scale population-based cohort study in Korea

An association between appendectomy and subsequent gastrointestinal (GI) cancer development has been postulated, although the evidence is limited and inconsistent. To provide clarification, we investigated the link between appendectomy and GI cancers in a large nationwide appendectomy cohort. This cohort was derived from the claims database of the National Health Insurance Service in South Korea and comprised 158,101 patients who had undergone appendectomy between 2007 and 2014. A comparison cohort of 474,303 subjects without appendectomy was selected after 1:3 matching by age and sex. The incidence of GI cancers after appendectomy was observed, and risk factors for GI cancers were determined by using a multivariable-adjusted proportional hazards model. Appendectomy did not significantly increase the incidence of GI cancers in the overall population (1.529 and 1557 per 1000 person-years in the non-appendectomy and appendectomy cohorts, respectively). However, appendectomy significantly increased the incidence of GI cancers in subgroups consisting of elderly (≥ 60 years) patients (adjusted HR, 1.102; 95% confidence interval, 1.011-1.201; p = 0.028) or women (adjusted HR, 1.180; 95% confidence interval, 1.066-1.306; p = 0.001).

Prospective cohort study of appendicectomy for treatment of therapy-refractory ulcerative colitis

Introduction

Appendicectomy may reduce relapses and need for medication in patients with ulcerative colitis, but long-term prospective data are lacking. This study aimed to analyse the effect of appendicectomy in patients with refractory ulcerative colitis.

Methods

In this prospective multicentre cohort series, all consecutive patients with refractory ulcerative colitis referred for proctocolectomy between November 2012 and June 2015 were counselled to undergo laparoscopic appendicectomy instead. The primary endpoint was clinical response (reduction of at least 3 points in the partial Mayo score) at 12 months and long-term follow-up. Secondary endpoints included endoscopic remission (endoscopic Mayo score of 1 or less), failure (colectomy or start of experimental medication), and changes in Inflammatory Bowel Disease Questionnaire (IBDQ) (range 32–224), EQ-5D™ and EORTC-QLQ-C30-QL scores.

Results

A total of 28 patients (13 women; median age 40·5 years) underwent appendicectomy. The mean baseline IBDQ score was 127·0, the EQ-5D™ score was 0·65, and the EORTC-QLQ-C30-QL score was 41·1. At 12 months, 13 patients had a clinical response, five were in endoscopic remission, and nine required a colectomy (6 patients) or started new experimental medical therapy (3). IBDQ, EQ-5D™ and EORTC-QLQ-C30-QL scores improved to 167·1 (P &lt; 0·001), 0·80 (P = 0·003) and 61·0 (P &lt; 0·001) respectively. After a median of 3·7 (range 2·3–5·2) years, a further four patients required a colectomy (2) or new experimental medical therapy (2). Thirteen patients had a clinical response and seven were in endoscopic remission. The improvement in IBDQ, EQ-5D™ and the EORTC-QLQ-C30-QL scores remained stable over time.

Conclusion

Appendicectomy resulted in a clinical response in nearly half of patients with refractory ulcerative colitis and a substantial proportion were in endoscopic remission. Elective appendicectomy should be considered before proctocolectomy in patients with therapy-refractory ulcerative colitis.

Encorafenib inhibits migration, induces cell cycle arrest and apoptosis in colorectal cancer cells

Encorafenib, a new-generation BRAF inhibitor, has been approved by FDA for the treatment of melanoma in combination with binimetinib. However, the mechanism of the drug works in colorectal cancer (CRC) is still unclear. In this study, the suppression of growth of CRC cells by encorafenib was investigated. The effects of treatment of encorafenib on pathways linked to cancer were studied, and the effective inhibition of cell proliferation was documented. Our findings showed that cell migration was inhibited by encorafenib through a likely involvement of MPP and TIMP modulation. Furthermore, encorafenib treatment also induced cell cycle arrest. In addition, induction of apoptosis in CRC cells by elevating levels of PUMA. These observations indicate the potential therapeutic efficacy of encorafenib on CRC.