Pyroptosis burden is associated with anti-TNF treatment outcome in inflammatory bowel disease: new insights from bioinformatics analysis.

Biological agents known as anti-tumor necrosis factor (TNF) drugs are frequently utilized in the treatment of inflammatory bowel disease (IBD). In this study, we analyzed the shared processes of pyroptosis in Ulcerative colitis (UC) and Crohn's disease (CD), as well as explored the correlation between the burden of pyroptosis and the results of anti-TNF treatment based on bioinformatics analyses. We identified CAPS1, CASP5, GSDMD, AIM2, and NLRP3 as the hub genes, with AIM2 being the most effective indicator for predicting the response to anti-TNF therapy. We also noticed that non-responders received anti-TNF therapy exhibited elevated AIM2 protein expression. Subsequently, we conducted a cluster analysis based on AIM2-inflammasome-related genes and discovered that patients with a higher burden of AIM2 inflammasome displayed stronger immune function and a poor response to anti-TNF therapy. Overall, our study elucidates the pathway of pyroptosis in IBD and reveals AIM2 expression level as a potential biomarker for predicting the effectiveness of anti-TNF therapy.

Endoscopic features help to identify the histopathological patterns of colorectal polyps in Cronkhite-Canada syndrome.

OBJECTIVES: Cronkhite-Canada syndrome (CCS) is a rare nonhereditary gastrointestinal hamartomatous polyposis syndrome with a high risk of colorectal cancerogenesis. It is challenging to discriminate adenomas from nonneoplastic colorectal polyps macroscopically. This study aimed to explore the endoscopic features of different histopathological patterns of colorectal polyps in CCS. METHODS: Sixty-seven lesions from 23 CCS patients were prospectively biopsied or resected during the colonoscopic examination for histopathological analysis. The Fisher's exact test and multivariate logistical analysis were conducted to reveal the predictive endoscopic features of CCS polyps with low-grade dysplasia (LGD) and adenomas. RESULTS: There were seven (10.4%) adenomas, 20 (29.9%) CCS-LGD, and 40 (59.7%) nonneoplastic CCS polyps. Polyps were large (>20 mm) in none of the adenomas, 30.0% of CCS-LGD polyps, and 2.5% of nonneoplastic CCS polyps (P < 0.001). The color of the polyps was whitish for 71.4% of adenomas, 10.0% of CCS-LGD polyps, and 15.0% of nonneoplastic CCS polyps (P = 0.004). Pedunculated polyps were detected in 42.9% of adenomas, 45.0% of CCS-LGD polyps, and 5.0% of nonneoplastic CCS polyps (P < 0.001). The proportions of types IV and VI in the Kudo classification were 42.9%, 95.0%, and 35.0% in adenomatous, CCS-LGD, and nonneoplastic CCS polyps, respectively (P = 0.002). The endoscopic activity was in remission for 71.4% of adenomas, 5.0% of CCS-LGD polyps, and 10.0% of nonneoplastic CCS polyps (P < 0.001). CONCLUSION: Endoscopic features, including the size, color, sessility, Kudo's pit pattern classification of polyps, and endoscopic activity, help identify the histopathological patterns of colorectal polyps in CCS.

The metabolic syndrome and its components as prognostic factors in colorectal cancer: A meta-analysis and systematic review.

BACKGROUND AND AIM: Metabolic syndrome (MetS) increases the risk of colorectal cancer (CRC), and the impact of MetS on CRC prognosis remains controversial after the diagnosis of CRC has been established. This study aimed to explore the impact of the individual components and synergies of MetS on the prognosis of patients with CRC. METHODS: We searched articles published before August 3, 2022, in four databases, including PubMed, Embase, Cochrane Library, and ScienceDirect. The random-effects model inverse variance method was used to estimate the summarized effect size. RESULTS: Patients with CRC with MetS were 1.342 times more likely to experience all-cause mortality than those without MetS, and the 95% confidence interval (CI) of hazard ratio (HR) was 1.107-1.627 (P = 0.003). CRC-specific mortality in patients with CRC with MetS was 2.122 times higher than in those without MetS, and the 95% CI of HR was 1.080-4.173 (P = 0.029). CRC-specific mortality exhibited an increasing trend of risk with increased metabolic risk factors. The HR of CRC-specific mortality for one, two, and three metabolic risk factors was 1.206 (95% CI, 1.034-1.407; P = 0.017), 1.881 (95% CI, 1.253-2.824; P = 0.002), and 2.327 (95% CI, 1.262-4.291; P = 0.007), respectively. CONCLUSIONS: Metabolic syndrome increased all-cause and CRC-specific mortality in patients with CRC. As a single component of MetS, diabetes mellitus increased overall mortality in patients with CRC, while obesity increased CRC-specific mortality in patients with CRC, with a significant difference from non-MetS. Moreover, the risk of CRC-specific mortality increased with increasing number of metabolic risk factors.

External validation of the Paddington International Virtual Electronic ChromoendoScopy ScOre as a good endoscopic score to define mucosal healing and predict long-term clinical outcomes in ulcerative colitis.

OBJECTIVES: To define endoscopic and histological remission in ulcerative colitis (UC) accurately, several scoring systems have been established. A novel virtual electronic chromoendoscopy score, the Paddington International Virtual ChromoendoScopy ScOre (PICaSSO), was developed, validated, and reproduced to assess inflammation grade and predict patient prognosis. We externally verified and validated the clinical value of PICaSSO in UC patients. METHODS: This prospective study enrolled 63 UC patients. The Mayo endoscopic score (MES), UC Endoscopic Index of Severity (UCEIS), and PICaSSO were adopted for endoscopic evaluation. All biopsy samples were scored using the Robarts histological index (RHI), Nancy histological index (NHI), and "Extent, Chronicity, Activity, Plus additional findings" (ECAP) score. Patients with an endoscopic MES of 0-1 at baseline were followed up during a median time of 23.5 months. RESULTS: PICaSSO was strongly correlated with other endoscopic and histological scoring systems. PICaSSO ≤3 had advantages in assessing histological remission (HR), with the highest accuracy of 88.9% for ECAP-HR. Relapse-free survival rates were significantly different between patients with MES 0 and MES 1 and patients with PICaSSO ≤3 and >3 (P = 0.010 and 0.018, respectively). CONCLUSIONS: PICaSSO was externally validated with strong correlations with other endoscopic and histological scoring systems in UC, and PICaSSO-ER might potentially predict a better long-term clinical outcome in UC patients.

Gut microbiota shed new light on the management of immune-related adverse events.

Immunotherapy has dramatically revolutionized the therapeutic landscape for patients with cancer. Although immune checkpoint inhibitors are now accepted as effective anticancer therapies, they introduce a novel class of toxicity, termed immune-related adverse events, which can lead to the temporary or permanent discontinuation of immunotherapy and life-threatening tumor progression. Therefore, the effective prevention and treatment of immune-related adverse events is a clinical imperative to maximize the utility of immunotherapies. Immune-related adverse events are related to the intestinal microbiota, baseline gut microbiota composition is an important determinant of immune checkpoint inhibitor-related colitis, and antibiotics exacerbate these undesirable side-effects. Supplementation with specific probiotics reduces immune checkpoint inhibitor-related colitis in mice, and fecal microbiota transplantation has now been shown to effectively treat refractory immune checkpoint inhibitor-related colitis in the clinic. Hence, modifying the microbiota holds great promise for preventing and treating immune-related adverse events. Microbiomes and their metabolites play important roles in the potential underlying mechanisms through interactions with both innate and adaptive immune cells. Here we review the gut microbiota and immune regulation; the changes occurring in the microbiota during immune checkpoint inhibitor therapy; the relationship between the microbiota and immune-related adverse events, antibiotics, probiotics/prebiotics, and fecal microbiota transplantation in immune checkpoint inhibitor-related colitis; and the protective mechanisms mediated by the microbiome and metabolites in immune-related adverse events.

Identification and Validation of Prognosis-Related Necroptosis Genes for Prognostic Prediction in Hepatocellular Carcinoma.

Background: The prediction of hepatocellular carcinoma (HCC) survival is challenging because of its rapid progression. In recent years, necroptosis was found to be involved in the progression of multiple cancer types. However, the role of necroptosis in HCC remains unclear. Methods: Clinicopathological parameters and transcriptomic data of 370 HCC patients were obtained from TCGA-LIHC dataset. Prognosis-related necroptosis genes (PRNGs) were identified and utilized to construct a LASSO risk model. The GEO cohorts (GSE54236 and GSE14520) were used for external validation. We evaluated the distribution of HCC patients, the difference in prognosis, and the accuracy of the prognostic prediction of the LASSO risk model. The immune microenvironment and functional enrichment of different risk groups were further clarified. Finally, we performed a drug sensitivity analysis on the PRNGs that constructed the LASSO model and verified their mRNA expression levels in vitro. Results: A total of 48 differentially expressed genes were identified, 23 of which were PRNGs. We constructed the LASSO risk model using nine genes: SQSTM1, FLT3, HAT1, PLK1, MYCN, KLF9, HSP90AA1, TARDBP, and TNFRSF21. The outcomes of low-risk patients were considerably better than those of high-risk patients in both the training and validation cohorts. In addition, stronger bile acid metabolism, xenobiotic metabolism, and more active immune cells and immune functions were observed in low-risk patients, and high expressions of TARDBP, PLK1, and FLT3 were associated with greater drug sensitivity. With the exception of FLT3, the mRNA expression of the other eight genes was verified in Huh7 and 97H cells. Conclusions. The PRNG signature provides a novel and effective method for predicting the outcome of HCC as well as potential targets for further research.

The genomic landscape of Cronkhite-Canada syndrome: Possible clues for pathogenesis.

OBJECTIVES: Cronkhite-Canada syndrome (CCS) is a rare hamartomatous polyposis syndrome with a proposed association with chronic autoimmune inflammation. To date, genetic background of patients with CCS remains less investigated. In this study we aimed to explore the genomic landscape of CCS. METHODS: Whole exome sequencing was performed on peripheral blood samples extracted from 18 patients with CCS. Potential function-impacting germline variants were filtered by R software. Through systematic data analysis, a number of genetic variants were identified. Enrichment analysis was performed using the R package ClusterProfiler. RESULTS: Overall, 3960 low-frequency (<0.05 or not reported in the Exome Aggregation Consortium East Asian, 1000 Genomes, or ESP6500 database) potentially function-impacting germline variants were identified, with 18 genes (FDFT1, LOC400863, MUC3A, MUC4, ZNF806, GXYLT1, MUC6, PABPC3, PSPH, ZFPM1, CIC, LOC283710, ARSD, GOLGA6L2, LOC388282, SLC25A5, TMEM247, WDR89) involved over half the patients. Functional enrichment of these genes revealed several biological processes in relation to innate immune responses and glycosylation. Only one likely pathogenic germline variant of an hamartomatous polyposis syndrome-associated gene, PTCH1, was detected in one patient. CONCLUSIONS: CCS has genomic alteration patterns completely distinct from those of traditional hamartomatous polyposis syndrome. The germline mutation landscape indicates potential roles of innate immune responses and glycosylation in the pathogenesis of CCS.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition).

OBJECTIVE: Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden. METHODS: Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements. RESULTS: Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases. CONCLUSION: H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Hamartomatous polyposis syndrome associated malignancies: Risk, pathogenesis and endoscopic surveillance.

Hamartomatous polyposis syndromes (HPS) are a heterogeneous spectrum of diseases that are characterized by diffuse hamartomatous polyps lining the gastrointestinal (GI) tract together with extra-GI manifestations. Classical HPS includes juvenile polyposis syndrome, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome and hereditary mixed polyposis syndrome. Patients with HPS have a higher risk of GI and extra-GI malignancies than the general population, although the underlying mechanisms remain unclear and are obviously different from the carcinogenesis of classical adenocarcinoma and colitis-associated malignancy. In this review we aimed to clarify the risks, possible mechanism and endoscopic surveillance of HPS-associated GI malignancies.

Predicting Mucosal Proliferation in Ulcerative Colitis by Assessing Mucosal Vascular Pattern Under Narrow Band Imaging Colonoscopy.

BACKGROUND: Proliferative abnormalities are believed to represent an early phase of colorectal carcinogenesis. Narrow band imaging (NBI) colonoscopy allows visual assessment of the mucosal vascular pattern (MVP) without dyeing. The aim of this study was to investigate the predictive value of MVP for mucosal proliferation in ulcerative colitis (UC). METHODS: A total of 119 colorectal lesions were analyzed from 42 patients with UC who underwent NBI colonoscopy. Both the MVP and the Mayo endoscopic score (MES) were assessed. The mucosal inflammation was histologically graded using a colitis score. The proliferation marker Ki-67 was assessed by immunohistochemical staining. RESULTS: The results showed that MVP correlated well with the MES (r = 0.796, P < .001). There was moderate correlation between the distribution of Ki-67 staining and MVP (r = 0.492, P < .001), and the Ki-67 labeling index increased with the orderly patterns of MVP (P < .001). An expansion of Ki-67 staining upward from the crypt base may be caused by active inflammation. CONCLUSION: MVP based on NBI colonoscopy can predict mucosal proliferation which is associated with inflammation in patients with UC.

Clinical-radiological characteristics and intestinal microbiota in patients with pancreatic immune-related adverse events.

BACKGROUND: The pancreatic immune-related adverse event (irAE) is a rare but increasingly occurrence disease with limited knowledge, which was associated with the use of immune checkpoint inhibitors (ICIs). METHODS: In this case series study of pancreatic irAE patients, clinical and radiological manifestations are summarized. Baseline and post-treatment fecal microbiota of immune-related acute pancreatitis (irAP) patients were analyzed by the 16 s rDNA amplicon sequencing method. RESULTS: A total of six patients were enrolled into the study, and the onset of pancreatic irAEs occurred a median of 105 days after a median of 4.5 cycles with immune checkpoint inhibitors (ICIs). All patients had an effective response to ICIs. Abdominal pain was the main clinical manifestation. Serum amylase (sAMY) and lipase (sLIP) had dynamic changes parallel to clinical severity. Contrast-enhanced computed tomography (CT) did not accurately reveal the level of inflammation. However, magnetic resonance imaging (MRI) was a sensitive imaging method which showed decreased and increased signal intensity of pancreatic parenchyma in T1-weighted fat-saturated and diffusion-weighted imaging, respectively. Glucocorticoids were the main treatment with a rapid initial effect followed by a slow improvement. After reinitiation of ICI therapy, pancreatic irAEs either deteriorated, remained stable or the patient developed severe pancreatic ß-cell destruction without irAP recurrence. The baseline microbiota of irAP had low Bacteroidetes/Firmicutes ratio at phylum level, low relative abundance of Alistipes, Bacteroides and high Lachnospiraceae at genus level, compared to levels of pancreatic ß-cell destruction and post-treatment of irAP. CONCLUSIONS: Pancreatic irAE patients had corresponding abdominal pain and increase in sAMY/sLIP. MRI was found to be an ideal imaging modality. Treatment with glucocorticoids were the main approach. The microbiota showed relative changes at baseline and during treatment.

Endoscopic resection for non-polypoid dysplasia in inflammatory bowel disease: a systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis aims to evaluate efficacy and safety of endoscopic treatment for the non-polypoid dysplasia in patients with long-standing IBD. METHODS: Medline, Embase, Cochrane, and clinicaltrials.gov registry were comprehensively searched. Pooled estimates of curative, R0, en-bloc resection rates, CRC, metachronous dysplasia, and local recurrence rates were calculated. Subgroup analysis according to areas, lesion size, endoscopic resection techniques, and grades of dysplasia were conducted. Data synthesis was completed in R using the package "meta". RESULTS: Of the 973 studies initially identified, 7 met the inclusion/exclusion criteria. These were all single-arm cohorts and included a total of 202 patients with IBD and non-polypoid dysplasia. The combined R0 and en-bloc resection rate were 0.70 (95% CI 0.55-0.81) and 0.86 (95% CI 0.65-0.95), respectively, with a recurrence rate of 0.08 (95% CI 0.05-0.13). CRC and metachronous dysplasia incidences were pooled as 32.53 (95% CI 12.21-86.67) and 90.24 (95% CI 44.91-181.33) per 1000 patient years. CONCLUSIONS: Non-polypoid dysplasia associated with IBD can be resected endoscopically, especially by ESD. However, these patients have higher CRC and metachronous dysplasia incidence rates than patients with polypoid dysplasia, indicating a closer endoscopic surveillance.

[Extraintestinal manifestations and intestinal complications in children with Crohn's disease: an analysis of 54 cases].

OBJECTIVE: To summarize the extraintestinal manifestations and intestinal complications in children with Crohn's disease (CD). METHODS: The clinical data of 54 children who were diagnosed with CD in Peking Union Medical College Hospital from January 2008 to December 2018 were collected for retrospective analysis of extraintestinal manifestations and intestinal complications. According to the location of the lesion, the children were divided into ileocolonic group (30 cases), colonic group (6 cases), and ileal group (18 cases). RESULTS: In the 54 children, the mean age at diagnosis was 14.5±2.7 years, and the median duration from disease onset to definite diagnosis was 20 months (range: 1-36 months). Twenty-four patients (44%) had extraintestinal manifestations, with the two most common manifestations being growth retardation (11 cases, 20%) and oral mucosal ulcer (10 cases, 19%), followed by arthritis (2 cases, 4%), erythema nodosum (2 cases, 4%), and cholecystitis (2 cases, 4%). There were no significant differences in the incidence of extraintestinal manifestations among the three groups (P=0.792). The most common intestinal complications were anal fistula/perianal abscess (13 cases, 24%), followed by intestinal fistula (5 cases, 9%) and intestinal obstruction (4 cases, 7%). There was a significant difference in the incidence of intestinal complications among the three groups (P=0.0406). No intestinal complications were reported in the colonic group. CONCLUSIONS: Extraintestinal manifestations and intestinal complications are common in children with CD. Perianal examinations should be performed in children with suspected CD. Intestinal complications are less common in children with colonic CD, which may be associated with relatively mild disease condition.

Jejunal cavernous lymphangioma manifested as gastrointestinal bleeding with hypogammaglobulinemia in adult: A case report and literature review.

BACKGROUND: Lymphangioma is a benign lesion that rarely involves the gastrointestinal tract, especially in adults. Small bowel lymphangioma is a rare cause of gastrointestinal bleeding. Here, we report a case of an adult diagnosed with jejunal lymphangioma presenting with melena, anemia and hypogammaglobulinemia. We also summarize and analyze all 23 reported cases from 1961 to 2019, and propose an algorithm for identification and management of small bowel lymphangioma. CASE SUMMARY: A case of a 29-year-old woman presented with persistent melena and iron-deficiency anemia, accompanied by hypogammaglobulinemia. No lesions were found in the initial workup with esophagogastroduodenoscopy, colonoscopy and computed tomography (CT) enterography. Ultimately, capsule endoscopy and double-balloon enteroscopy revealed a 3 cm × 2 cm primary lesion with intensive white lymphatic dilatatory changes and visible fresh blood stains, accompanied by a small satellite lesion. The patient underwent complete surgical resection of these lesions, and histopathological examination confirmed a diagnosis of cavernous lymphangioma of the jejunum. The patient showed no evidence of disease at the time of this report. CONCLUSION: We recommend CT, capsule endoscopy and enteroscopy to identify the lesions of lymphangioma. Laparoscopic surgery with histological diagnosis is an ideal curative method.

Primary hypertrophic osteoarthropathy related gastrointestinal complication has distinctive clinical and pathological characteristics: two cases report and review of the literature.

BACKGROUND: Primary hypertrophic osteoarthropathy (PHO) is a rare disease related to HPGD and SLCO2A1 gene mutation. Gastrointestinal involvement of PHO is even rarer with unknown pathogenesis. Clinical features of GI complication in PHO mimics other auto-immune based bowel entities, such as inflammatory bowel diseases and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE). We aimed to analyze the clinical, genetic, radiological and pathological features of Chinese patients with PHO and determine the difference between PHO patients presenting with and without GI involvement. METHODS: We reported two PHO cases with gastrointestinal involvement and reviewed all the studies of PHO in Chinese population published from January 1, 2000, to April 30, 2018. Clinical and genetic presentations of PHO in Chinese patients were analyzed. We compared the characteristics of those patients with gastrointestinal involvement against those without. RESULTS: The two patients were both males with complete-form PHO for more than 10 years. GI related symptoms included diarrhea, chronic gastrointestinal hemorrhage, incomplete intestinal obstruction, anemia, and edema, which were unresponsive to etoricoxib treatment. Radiological examinations revealed segmental intestinal stenosis and thickened intestinal wall. Endoscopic findings included multiple ulcers and mucosal inflammation. Both patients had mutations of SLCO2A1 according to sequence analysis. The surgical pathology revealed chronic inflammation involving the intestinal mucosa and submucosa, similar to histological changes in CMUSE. According to the systemic review of 158 Chinese patients with PHO, 17.2% had gastrointestinal involvement, including peptic ulcer, gastric polyps, hypertrophic gastritis, and segmental intestinal stenosis. Patients with gastrointestinal involvement were more likely to have anemia (40.0% vs. 4.5%, P < 0.001), hypoalbuminemia (16.7% vs. 0.9%, P = 0.003), and myelofibrosis (19.0% vs. 0.9%, P = 0.002) than those without. Most patients with gastrointestinal complication had SLCO2A1 mutation (86.7%, 13 /15). CONCLUSIONS: Digestive tract involvement is uncommon in patients with PHO and often presents with anemia, and hypoalbuminemia resulted from intestinal inflammation. The intestinal pathologic characteristics are distinct from Crohn's disease but similar to CMUSE. Mutations in SLCO2A1 might be the pathogenic cause of GI involvement of PHO. NSAIDs may not be effective for PHO patients with gastrointestinal complications.

Improvement of Asia-Pacific colorectal screening score and evaluation of its use combined with fecal immunochemical test.

BACKGROUND: The Asia-Pacific Colorectal Screening (APCS) score is effective to screen high-risk groups of advanced colorectal neoplasia (ACN) patients but needs revising and can be combined with the fecal immunochemical test (FIT). This paper aimed to improve the APCS score and evaluate its use with the FIT in stratifying the risk of ACN. METHODS: This prospective and multicenter study enrolled 955 and 1201 asymptomatic Chinese participants to form the derivation and validation set, respectively. Participants received the risk factor questionnaire, colonoscopy and FIT. Multiple logistic regression was applied, and C-statistic, sensitivity and negative predictive values (NPVs) were used to compare the screening efficiency. RESULTS: A modified model was developed incorporating age, body mass index (BMI), family history, diabetes, smoking and drinking as risk factors, stratifying subjects into average risk (AR) or high risk (HR). In the validation set, the HR tier group had a 3.4-fold (95% CI 1.8-6.4) increased risk for ACN. The C-statistic for the modified score was 0.69 ± 0.04, and 0.67 ± 0.04 for the original score. The sensitivity of the modified APCS score combined with FIT for screening ACN high-risk cohorts was 76.7% compared with 36.7% of FIT alone and 70.0% of the modified APCS score alone. The NPVs of the modified score combined with FIT for ACN were 98.0% compared with 97.0% of FIT alone and 97.9% of the modified APCS score alone. CONCLUSIONS: The modified score and its use with the FIT are efficient in selecting the HR group from a Chinese asymptomatic population.

Similarities and differences in clinical and pathologic features of inflammatory bowel disease-associated colorectal cancer in China and Canada.

BACKGROUND: Colorectal cancer (CRC) has become one of the major life-threatening complications in patients with inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). This study aimed to explore the clinical-pathologic similarities and differences in the IBD-associated CRC (IBD-CRC) between patients in China and Canada. METHODS: Data of 78 patients with IBD-CRC retrospectively retrieved from two representative medical institutions in Beijing (China) and Calgary (Canada) over the same past 13 years, including 25 (22 UC-associated and three CD-associated) from Beijing group and 53 (32 UC-associated and 21 CD-associated) from Calgary group, were compared with regards to their clinical and pathologic characteristics. RESULTS: Several known features of IBD-CRC were seen in both groups, including long duration and large extent of colitis, active inflammation background, multifocal lesions, and advanced tumor-node-metastasis stage. Beijing group showed a significantly higher percentage of UC (88.0% vs. 60.4%, P = 0.018), younger age at diagnosis of CRC (48.6 ±â€Š12.8 years vs. 61.6 ±â€Š14.7 years, P < 0.001), lower ratio of mucinous adenocarcinoma (7.1% vs. 42.4%, P = 0.001) compared with Calgary group. None of the Beijing group had concurrent primary sclerosing cholangitis, while 5.7% of Calgary group did. Surveillance colonoscopy favored the detection rate of precancerous lesions (41.4% vs.17.0%, P = 0.002). CONCLUSIONS: As compared with patients from the Calgary group, the IBD-CRC patients in Beijing group were younger, less CD-associated and had less mucinous features, otherwise they were similar in many common features.