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Background/Aims The human gut microbiota serves as an important component in the pathogenesis of Crohn's disease (CD) that promote host-microbe imbalances leading to perturbed intestinal and immune homeostasis. In this study, we aimed to assess the potential clinical usefulness of using the colonic tissue microbiome by which biomarkers for upper gastrointestinal (UGI) involvement of CD could be obtained. Methods We analyzed colonic tissue samples from 26 patients with CD, including 13 with and 13 without UGI involvement at diagnosis from the Inflammatory Bowel Disease Multi-Omics Database. Metagenomic analysis of the V3-V4 region of the 16S ribosomal RNA gene was performed using QIIME1, DiTaxa and linear discriminant analysis effect size (LEfSe) method. Results Non-metric multidimensional scaling using Bray-Curtis distances revealed a complex pattern of community structures. There were no statistically significant differences in the community richness estimator (Chao) and the diversity estimator (Shannon index) between the CD patients with and without UGI involvement. The overall abundance of the genus Bacteroides was significantly increased in the patients with UGI involvement compared with those without UGI involvement. Taxa predicted by DiTaxa had the species Ruminococcus torques as significantly associated with UGI involvement, which was confirmed based on the LEfSe analysis (p=0.025). Conclusions These finding suggest that the species Ruminococcus torques might serve as a novel potential biomarker for UGI involvement of CD and its correlations in abundance with a range of bacterial species. The mechanisms of interactions between hosts and Ruminococcus torques should be further investigated. [ABSTRACT FROM AUTHOR]

Background/Aims No risk prediction algorithm using deep neural network (DNN) was developed to predict the risk of advanced colorectal neoplasia (ACRN). This study aimed to compare DNN models and simple clinical score models for the prediction of ACRN in colorectal cancer screening. Methods Datasets of screening colonoscopy (n=121,794) at Kangbuk Samsung Hospital as well as database of screening colonoscopy (n=3,738) at Gangdong Kyung Hee University Hospital were used for development of DNN-based model. Two DNN models were developed and compared with two conventional risk prediction models, Asian-Pacific Colorectal Screening (APCS) and Korean Colorectal Screening (KCS) models, to predict ACRN. The area under the receiver operating characteristic curves (AUROCs) of the models was compared in both internal and external validation datasets. Results In the internal test set, the AUROCs of DNN model 1 and AUROCs score were 0.713 and 0.661 (p<0.001), and the AUROCs of DNN model 2 and KCS score were 0.730 and 0.667 (p<0.001), respectively. However, in the external test set, the prediction performances were not significantly different between two DNN models and corresponding APCS and KCS score, respectively (both p>0.1). Conclusions Simple score models for risk-stratification of ACRN could be as useful as DNN-based models when input variables are limited. However, further studies on this issue may be warranted to predict a risk of ACRN in colorectal cancer screening because DNN-based models are currently being improved. [ABSTRACT FROM AUTHOR]

Background/Aims Biologicals like anti-tumor necrosis factor (TNF) therapy for Crohn's disease (CD) are safe and effective but there is a significant rate of primary and secondary nonresponse in the patients. In this study, we applied a computational approach to discover novel drug therapies for anti-TNF refractory CD in silico. Methods We use a transcriptome dataset (GSE100833) for the anti-TNF refractory CD patients from NCBI GEO. After co-expression analysis, we specifically investigated the extent of protein-protein interactions among genes in clusters based on a protein-protein interaction database, STRING. Pathway analysis was performed using the clEnrich function based on reactome gene sets. Results Co-expressed genes in cluster 1, 2, 3, 5, 8, up or downregulated genes and all differential expression genes are highly connected, while genes in other clusters are less connected. Furthermore, based on the ratio of actual interaction and expected interaction, the connectivity between genes in cluster 1 (with ratio value, 8), 2 (18), 3 (4.33) and 5 (23) is higher than those in other clusters. Among them, cluster 3, which is highly enriched for CTLA4-inhibitory signaling, also showed enrichment for immune related pathways and identifies several drugs including mercaptopurine and ciclosporin with known efficacy in CD. Piperlongumine, which is known to have inhibitory effect on activity of NF-κB, and CP-690334-01 alleviating proinflammatory responses of CD8+ T cells were also identified. Conclusions These finding suggest that piperlongumine and CP-690334-01 might serve as a novel therapeutic option for anti-TNF refractory CD and support the use of public molecular data and computational approaches to discover novel therapeutic options for CD. [ABSTRACT FROM AUTHOR]

Background/Aims Although dysbiosis has been reported in Crohn's disease (CD) compared with healthy controls (HC), limited studies have examined the intestinal microbiota composition in relation to prognosis of CD. We aim to analyze difference in microbial communities and relevant metabolic pathways according to the prognosis of CD. Methods We analyzed a cohort of 370 CD and 740 HC fecal samples from 14 centers in Korea, applied a 16S rRNA sequencing approach. We categorized CD patients into three groups as good (CD-G), intermediate (CD-I), and poor (CD-P) prognosis group according to history of using biologics and intestinal resection. The microbial composition, diversity and microbial community function were analyzed. Results Microbiota α-diversity was decreased in within all CD groups vs HC, with more significant reduction in CD-P compared with CD-G and CD-I. β-Diversity indicated different microbial patterns in CD-P compared with CD-G and CD-I. Among microbiota that were differentially abundant between HC and CD groups, 13 genera and 10 species showed difference abundance between CD-G and CD-P groups (Fig. 1). Escherichia coli from proteobacteria phylum and species Producta and genera Lactobacillus and Coprococcus from Firmicutes phylum consistently showed difference between CD-G and CD-P groups after adjusting for confounding clinical variables. In functional profiling, the increased microbial catabolic pathways, pathways related to enterobacterial common antigen and LPS biosynthesis were presented in the CD-P group than the CD-G group. Family Enterobacteriaceae or its species E. coli were the top contributor for these pathways. Conclusions CD prognosis is associated with changes in microbiota composition and decreased diversity. Specific bacteria such as E. coli might not only causally involved in CD progression but also adapted to live in inflammatory environment. [ABSTRACT FROM AUTHOR]

Background/Aims Population screening for colorectal cancer (CRC) is expected to increase the number of early stage tumor. The identification of simplified prediction model for lymph node metastasis (LNM) for early CRC is urgently needed to determine the treatment and follow-up strategies. This study aims to develop an accurate prediction model for the LNM in early CRC. Methods We used data from the 2004 to 2016 Surveillance, Epidemiology, and End Results database to develop and validate the prediction models for LNM. Six models, namely, neural network, naïve-Bayesian, Support vector machines, logistic regression, decision tree, and random forest (RF) models were assessed. Results A total of 32,725 patients with a diagnosis of early CRC (Tis and T1) were analyzed in the study. The model included eight independent prognostic variables, including age at diagnosis, sex, race, primary site, histologic type, tumor grade, tumor size, and tumor depth. LNM was significantly more frequently in patients with larger tumor, in elderly patients, and in patients with more poorly differentiated tumor. The RF algorithm had the best predictive performance in comparison to the other methods, achieving an accuracy of 94.7%, a sensitivity of 71.4%, a specificity of 92.2%, and an area under the curve of 0.90. Conclusions Our data show that the age at diagnosis is the most important feature in predicting LNM of early CRC in the RF model. We established a simplified reproducible predictive model for LNM in early CRC that could be used to guide treatment decisions. [ABSTRACT FROM AUTHOR]

The author discusses the measurement of colonoscopy's learning curve through detection rate of polyps, and its effectivenes as an endoscopic technique. Topics discussed include calculation of adenoma detection rate (ADR), diagnostic significance of polyp detection rate (PDR), and detection of adenomas in male patients.

Background/Aims: The impact of coronavirus disease 2019 (COVID-19) on the management of colorectal cancer (CRC) may worse in elderly population, as almost all COVID-19 deaths occurred in the elderly patients. This study aimed to evaluate the impact of COVID-19 on CRC management in the elderly population. Methods: The numbers of patients who underwent colonoscopy, who visited hospitals or operated for CRC in 2020 and 2021 (COVID-19 era) were compared with those in 2019, according to 3 age groups (≥ 70 years, 50-69 years, and ≤ 49 years), based on the nationwide, population-based database (2019-2021) in South Korea. Results: The annual volumes of colonoscopy and hospital visits for CRC in 2020 were more significantly declined in the old age group than in the young age group (both P< 0.001). In addition, the annual volume of patients operated for CRC numerically more declined in old age group than in young age group. During the first surge of COVID-19 (March and April 2020), old age patients showed statistically significant declines for the monthly number of colonoscopies (-46.5% vs. -39.3%, P<0.001), hospital visits (-15.4% vs. -7.9%, P<0.001), CRC operations (-33.8% vs. -0.7%, P<0.05), and colonoscopic polypectomies (-41.8% vs. -38.0%, P< 0.001) than young age patients, compared with those of same months in 2019. Conclusions: Elderly population are more vulnerable for the management of CRC during the COVID-19 pandemic. Therefore, the elderly population are more carefully cared for in the management of CRC during the next pandemic. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Prevalence, clinicopathologic characteristics, and predictors of interval colorectal cancers in Korean population," by C. J. Kim , Y. S. Jung, J. H. Park and colleagues in the 2013 issue.

Artificial intelligence is likely to perform several roles currently performed by humans, and the adoption of artificial intelligence-based medicine in gastroenterology practice is expected in the near future. Medical image-based diagnoses, such as pathology, radiology, and endoscopy, are expected to be the first in the medical field to be affected by artificial intelligence. A convolutional neural network, a kind of deeplearning method with multilayer perceptrons designed to use minimal preprocessing, was recently reported as being highly beneficial in the field of endoscopy, including esophagogastroduodenoscopy, colonoscopy, and capsule endoscopy. A convolutional neural network-based diagnostic program was challenged to recognize anatomical locations in esophagogastroduodenoscopy images, Helicobacter pylori infection, and gastric cancer for esophagogastroduodenoscopy; to detect and classify colorectal polyps; to recognize celiac disease and hookworm; and to perform small intestine motility characterization of capsule endoscopy images. Artificial intelligence is expected to help endoscopists provide a more accurate diagnosis by automatically detecting and classifying lesions; therefore, it is essential that endoscopists focus on this novel technology. In this review, we describe the effects of artificial intelligence on gastroenterology with a special focus on automatic diagnosis, based on endoscopic findings. [ABSTRACT FROM AUTHOR]

Background/Aims: The adoption of colonoscopy as a primary colorectal cancer (CRC) screening technique has been argued for in Korea, without evidence of patient preferences. This study aimed to investigate patients' preferences for the primary CRC screening test for the National Cancer Screening Program (NCSP). Methods: Between June and August 2016, 414 individuals aged ≥50 years who participated in the NCSP were prospectively invited to complete a questionnaire regarding their preferences for the primary CRC screening test and the reasons for their selection. Results: Among the 396 respondents who completed the questionnaire, 124 individuals (31.3%) preferred the fecal immunochemical test (FIT), whereas 272 individuals (68.7%) preferred colonoscopy. Elderly participants preferred the FIT (p<0.001), whereas participants with a higher education level (p=0.030), a higher income level (p=0.009), or individuals with a family member (p=0.028) or acquaintance (p=0.013) with a history of CRC preferred colonoscopy. Only 12.9% of participants had a bad experience with a previous FIT; however, 39.3% of participants had a bad experience with a previous colonoscopy. Conclusions: Colonoscopy was preferred to FIT in a 2.2:1 ratio as the primary CRC screening test for the NCSP. Patients' preference for colonoscopy should be considered for the NCSP in Korea. [ABSTRACT FROM AUTHOR]

Background/Aims: Only a few studies have examined perceptions of the incidence and prognosis of colorectal cancer (CRC) in the general Korean population. The aim of this study was to determine public perceptions of the lifetime incidence rate and survival of CRC. Methods: All adults older than 50 years who visited the Kyung Hee University Hospital at Gangdong were invited to participate in this survey for 5 months in 2021. During the study period, eligible individuals participated in this survey through a link or quick response code on a poster posted in the hospital, which was linked to a web-based questionnaire. The questionnaire used for this survey included demographic and socioeconomic data, perceptions of CRC, and awareness of the CRC incidence and 5-year survival rate. Results: Among 203 respondents, 196 answers were analyzed after the exclusion of seven incomplete answers. In our survey, half of the respondents (49.5%) answered the expected lifetime incidence rate of CRC as 0% to 4.9%. Koreans perceived CRC as a more fatal disease than epidemiological data, as 70.9% of the respondents expected the 5-year survival rate of CRC to be less than 70% for the general population. However, Koreans perceived stage IV CRC as a less fatal disease than epidemiological data, because only 20.9% of the respondents expected the 5-year survival rate of stage IV CRC to be less than 10% for general population. Conclusions: Koreans recognized CRC as a more common and fatal disease than actual epidemiological data of CRC. Therefore, more efforts should be made to provide more correct information on CRC for better decision-making and communication. [ABSTRACT FROM AUTHOR]

Background. Predicting the course of depression is necessary for personalized treatment. Impaired glucose metabolism (IGM) was introduced as a promising depression biomarker, but no consensus was made. This study aimed to predict IGM at the time of depression diagnosis and examine the relationship between long-term prognosis and predicted results. Methods. Clinical data were extracted from four electronic health records in South Korea. The study population included patients with depression, and the outcome was IGM within 1 year. One database was used to develop the model using three algorithms. External validation was performed using the best algorithm across the three databases. The area under the curve (AUC) was calculated to determine the model’s performance. Kaplan–Meier and Cox survival analyses of the risk of hospitalization for depression as the long-term outcome were performed. A metaanalysis of the long-term outcome was performed across the four databases. Results. A prediction model was developed using the data of 3,668 people, with an AUC of 0.781 with least absolute shrinkage and selection operator (LASSO) logistic regression. In the external validation, the AUCs were 0.643, 0.610, and 0.515. Through the predicted results, survival analysis and meta-analysis were performed; the hazard ratios of risk of hospitalization for depression in patients predicted to have IGM was 1.20 (95% confidence interval [CI] 1.02–1.41, p = 0.027) at a 3-year follow-up. Conclusions. We developed prediction models for IGM occurrence within a year. The predicted results were related to the long-term prognosis of depression, presenting as a promising IGM biomarker related to the prognosis of depression. [ABSTRACT FROM AUTHOR]

Background/Aims: The prospective Crohn’s Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn’s disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35; 95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions: The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection. [ABSTRACT FROM AUTHOR]

We investigated whether the response to anti-tumor necrosis factor (anti-TNF) treatment varied according to inflammatory tissue characteristics in Crohn’s disease (CD). Bulk RNA sequencing (RNA-seq) data were obtained from inflamed and non-inflamed tissues from 170 patients with CD. The samples were clustered based on gene expression profiles using principal coordinate analysis (PCA). Cellular heterogeneity was inferred using CiberSortx, with bulk RNA-seq data. The PCA results displayed two clusters of CD-inflamed samples: one close to (Inflamed_1) and the other far away (Inflamed_2) from the non-inflamed samples. Inflamed_1 was rich in anti-TNF durable responders (DRs), and Inflamed_2 was enriched in non-durable responders (NDRs). The CiberSortx results showed that the cell fraction of activated fibroblasts was six times higher in Inflamed_2 than in Inflamed_1. Validation with public gene expression datasets (GSE16879) revealed that the activated fibroblasts were enriched in NDRs over Next, we used DRs by 1.9 times pre-treatment and 7.5 times after treatment. Fibroblast activation protein (FAP) was overexpressed in the Inflamed_2 and was also overexpressed in the NDRs in both the RISK and GSE16879 datasets. The activation of fibroblasts may play a role in resistance to anti-TNF therapy. Characterizing fibroblasts in inflamed tissues at diagnosis may help to identify patients who are likely to respond to anti-TNF therapy.

Background/Aims: Golimumab has been used for patients with ulcerative colitis (UC) since 2013. However, there is limited data on the effectiveness and safety of the real-world use of golimumab in Asian patients. Methods: This was a multicenter, prospective, observational study. We enrolled patients with moderate-to-severe UC who were administered subcutaneous golimumab at 46 medical centers between May 2014 and November 2019. The primary outcome was the effectiveness and safety of golimumab at week 22. Clinical outcomes and adverse events were assessed according to partial Mayo score at weeks 0, 2, 6, 14, and 22. Results: A total of 130 patients were included (mean age: 45.7±16.0 years). The clinical response/ remission rates at weeks 2, 6, 14, and 22 were 40.4%/22.9%, 56.0%/35.8%, 70.6%/49.5%, and 67.9%/48.6%, respectively. Based on full Mayo score at week 14, clinical response and remission rates were 84.2% and 39.5%, respectively. Mucosal healing rate was 65.8%. In multivariate analysis with logistic regression, longer disease duration was significantly associated with a higher clinical response rate (adjusted odds ratio [aOR], 1.136; 95% confidence interval [CI], 1.006 to 1.282; p=0.040 at week 6; aOR, 1.256; 95% CI, 1.049 to 1.503; p=0.013 at week 22). A higher baseline Mayo endoscopic sub score was significantly associated with a lower clinical response rate at week 6 (aOR, 0.248; 95% CI, 0.089 to 0.692; p=0.008). The incidence of adverse drug reactions was 4.6% (6/130, nine events). No serious unexpected adverse drug reactions or deaths were reported. Conclusions: Golimumab was effective and safe as an induction and maintenance treatment for Korean patients with moderate-to-severe UC. [ABSTRACT FROM AUTHOR]

Background/Aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested. This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy. Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions: The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy. [ABSTRACT FROM AUTHOR]

Background/Aims: The long-term course of Crohn’s disease (CD) has never been evaluated in non-Caucasian population-based cohorts. The aim of the present study was to evaluate the longterm prognosis of Korean CD patients in the well-defined population-based Songpa-Kangdong inflammatory bowel disease cohort. Methods: Outcomes of disease and their predictors were evaluated for 418 patients diagnosed with CD between 1986 and 2015. Results: During a median of 123 months, systemic corticosteroids, thiopurines, and anti-tumor necrosis factor (TNF) agents were administered to 58.6%, 81.3%, and 37.1% of patients, respectively. Over time, the cumulative probability of starting corticosteroids significantly decreased (p=0.001), whereas that of starting thiopurines and anti-TNFs significantly increased (both p<0.001). The cumulative probability of behavioral progression was 54.5% at 20 years, and it significantly decreased during the anti-TNF era. Intestinal resection was required for 113 patients (27.0%). The cumulative probabilities of intestinal resection at 1, 5, 10, 20, and 25 years after CD diagnosis were 12.7%, 16.5%, 23.8%, 45.1%, and 51.2%, respectively. Multivariable Cox regression analysis identified stricturing behavior at diagnosis (adjusted hazard ratio [aHR], 2.70; 95% confidence interval [CI], 1.55 to 4.71), penetrating behavior at diagnosis (aHR, 11.15; 95% CI, 6.91 to 17.97), and diagnosis of CD during the anti-TNF era (aHR, 0.51; 95% CI, 0.35 to 0.76) as independently associated with intestinal resection. The standardized mortality ratio among CD patients was 1.36 (95% CI, 0.59 to 2.68). Conclusions: The long-term prognosis of Korean patients with CD is at least as good as that of Western CD patients, as indicated by the low intestinal resection rate. Moreover, behavioral progression and intestinal resection rates have decreased over the past 3 decades. [ABSTRACT FROM AUTHOR]

Background/Aims: We aimed to evaluate the clinical characteristics and long-term prognosis of elderly-onset ulcerative colitis (EOUC) in Korean patients over a 30-year period using a well-established population-based cohort in the Songpa-Kangdong district of Seoul, Korea. Methods: Clinical characteristics and prognosis were compared between two groups: EOUC, defined as UC diagnosed in individuals aged ≥60 years and non-EOUC (N-EOUC), defined as UC diagnosed in individuals aged 18 to 59 years. Results: We identified 99 patients with EOUC (10.3%) and 866 patients with N-EOUC (89.7%) between 1986 and 2015. During the median follow-up of 104.5 months, the overall exposure to medications was comparable between patients with EOUC and N-EOUC (p=0.091 for corticosteroids, p=0.794 for thiopurines, and p=0.095 for anti-tumor necrosis factor agents). The cumulative risks of disease outcomes were also comparable between patients with EOUC and N-EOUC (22.4% vs 30.4% for proximal disease extension [p=0.351], 11.9% vs 18.1% for hospitalization [p=0.240], and 2.3% vs 1.8% for colectomy [p=0.977]) at 10 years after diagnosis. Multivariate Cox regression analysis revealed that corticosteroid use at diagnosis was an independent predictor of proximal disease extension (hazard ratio [HR], 6.216; 95% confidence interval [CI], 1.314 to 28.826) and hospitalization (HR, 11.241; 95% CI, 3.027 to 41.742) in patients with EOUC. Conclusions: In this population-based study from Korea, the pattern of medication use seemed comparable between the EOUC and N-EOUC groups. Moreover, patients with EOUC and those with N-EOUC have a similar disease course in terms of proximal disease extension, hospitalization, and colectomy. [ABSTRACT FROM AUTHOR]

Background/Aims: The global trend of an expanding aged population has increased concerns about complications correlated with gastrointestinal (GI) endoscopy in elderly patients; however, there have been few reports published on this issue. Methods: In this retrospective, observational cohort study performed between 2012 and 2017, serious complications of esophagogastroduodenoscopy (EGD), colonoscopy, and colonoscopic polypectomy were compared between patients according to age (≥65 years vs 18–64 years). We used the Health Insurance Review and Assessment-National Patient Samples database, previously converted to the standardized Observational Medical Outcomes Partnership-Common Data Model. Serious complications within 30 days of the procedure included both GI complications (bleeding and perforation) and non-GI complications (cerebrovascular accident [CVA], acute myocardial infarction [AMI], congestive heart failure [CHF], and death). Results: A total of 387,647 patients who underwent EGD, 241,094 who underwent colonoscopy, and 89,059 who underwent colonoscopic polypectomy were assessed as part of this investigation. During the study period, endoscopic procedures in the older group steadily increased in number in all endoscopy groups (all p<0.001). Further, pooled complication rates of bleeding, CVA, AMI, CHF, and death were approximately three times higher among older patients who underwent EGD or colonoscopy. Moreover, pooled complication rates of CVA, AMI, CHF, and death were approximately 2.2 to 5.0 times higher among older patients who underwent colonoscopic polypectomy. Conclusions: Elderly patients experienced approximately three times more GI and non-GI complications after EGD or colonoscopy than young patients. Physicians should pay attention to the potential risks of GI endoscopy in elderly patients. [ABSTRACT FROM AUTHOR]

Necrotizing fasciitis (NF) is a life-threatening infection that can be caused by various procedures or surgery and may develop in healthy elderly patients. Here, we report a case of a 66-year-old man with diabetes mellitus who underwent colonoscopic polypectomy, without complications. However, he visited the emergency department 24 hours after the procedure complaining of abdominal pain. Abdominopelvic computed tomography revealed multiple air bubbles in the right lateral abdominal muscles. After a diagnosis of NF was made, immediate surgical debridement was performed. However, despite three sessions of extensive surgical debridement and best supportive care at the intensive care unit, the patient died because of sepsis and NF-associated multiple-organ failure. In conclusion, physicians should pay special attention to the possibility of NF if a patient with risk factors for NF develops sepsis after colonoscopic polypectomy. [ABSTRACT FROM AUTHOR]

Crohn’s disease (CD) and ulcerative colitis (UC) can be difficult to differentiate. As differential diagnosis is important in establishing a long-term treatment plan for patients, we aimed to develop a machine learning model for the differential diagnosis of the two diseases using RNA sequencing (RNA-seq) data from endoscopic biopsy tissue from patients with inflammatory bowel disease (n = 127; CD, 94; UC, 33). Biopsy samples were taken from inflammatory lesions or normal tissues. The RNA-seq dataset was processed via mapping to the human reference genome (GRCh38) and quantifying the corresponding gene models that comprised 19,596 protein-coding genes. An unsupervised learning model showed distinct clusters of four classes: CD inflammatory, CD normal, UC inflammatory, and UC normal. A supervised learning model based on partial least squares discriminant analysis was able to distinguish inflammatory CD from inflammatory UC after pruning the strong classifiers of normal CD vs. normal UC. The error rate was minimal and affected only two components: 20 and 50 genes for the first and second components, respectively. The corresponding overall error rate was 0.147. RNA-seq analysis of tissue and the two components revealed in this study may be helpful for distinguishing CD from UC.

Background/Aims: Endoscopic diagnosis of dysplasia or colitic cancer in patients with ulcerative colitis (UC) is more challenging than that of colorectal neoplasia in non-colitic patients. We aimed to evaluate the accuracy of the endoscopic diagnosis of "nonpedunculated" dysplasia or colitic cancer in UC patients. Methods: Ten endoscopists from four countries were surveyed using photographs of 61 histologically confirmed dysplastic or non-dysplastic lesions retrieved from the UC registry database of Asan Medical Center. The participants provided their assessment based on the given photographs and their intention to perform biopsy. Results: The overall diagnostic performance of the 10 participants is summarized as follows: sensitivity of 88.2% (95% confidence interval [CI], 84.3% to 91.5%), specificity of 34.8% (95% CI, 29.1% to 40.8%), positive predictive value of 63.0% (95% CI, 60.8% to 65.2%), negative predictive value of 70.2% (95% CI, 62.7% to 76.6%), and accuracy of 64.6% (95% CI, 60.7% to 68.4%). The interobserver agreement on the intention to perform a biopsy was poor (Fleiss kappa=0.169). Of the three endoscopic characteristics of the lesions, including ulceration, distinctness of the borders, and pit patterns, only neoplastic pit patterns were significantly predictive of dysplasia (odds ratio, 3.710; 95% CI, 2.001 to 6.881). The diagnostic sensitivity and specificity of neoplastic pit patterns were 68.2% (95% CI, 63.0% to 73.2%) and 63.3% (95% CI, 57.3% to 69.1%), respectively. Conclusions: Diagnostic performance performance based on the endoscopist's intention to perform a biopsy for nonpedunculated potentially dysplastic lesions in UC patients was suboptimal according to this survey-based study. [ABSTRACT FROM AUTHOR]

Background/Aims: People around the world are increasingly choosing to undergo colorectal cancer screening via colonoscopy. As a result, guideline adherence to postpolypectomy colonoscopy surveillance has drawn increasing attention. The present study was performed to assess recognition and adherence to guidelines among primary care physicians and gastroenterologists and to identify characteristics associated with compliance. Methods: A nationwide sample of primary care physicians employed at cancer screening facilities and registered members of the Korean Society of Gastrointestinal Endoscopy were recruited. Participants were asked to complete a survey of six hypothetical clinical scenarios designed to assess their potential course of action in response to screening or follow-up colonoscopy results. Frequencies and odds ratios and 95% confidence intervals for guideline adherence were estimated. Results: The proportions of doctors recommending shortened colonoscopy surveillance intervals for low- and high-risk adenomas were greater than 90% among primary physicians and were much lower among gastroenterologists. Guideline adherence was relatively good among groups of doctors who were young, had a specialty in gastroenterology, worked at tertiary hospitals, and cared for an appropriate number of patients. Conclusions: The present study reveals a remaining discrepancy between practitioner recommendations and current guidelines for postpolypectomy surveillance. Several factors were shown to be related to guideline adherence, suggesting a need for appropriate control and continuing education or training programs among particular groups of practitioners. [ABSTRACT FROM AUTHOR]

Background: Risk scoring systems are used to evaluate patients with upper gastrointestinal bleeding (UGIB). We compared Glasgow-Blatchford score (GBS), modified GBS (mGBS), and Pre-endoscopy Rockall score (Pre-E RS) for immediate application without endoscopic findings in predicting the need of interventions and the 30-day mortality in patients with UGIB.Methods: Patients who visited the emergency room with UGIB from January 2007 to June 2016 were included. GBS, mGBS, and Pre-E RS were obtained for all patients. The area under the receiver-operating characteristic curves (AUC) was used to assess the accuracy of the scoring systems to determine the need for interventions and 30-day mortality. Also, we investigated the potential cutoff scores for predicting 30-day mortality and the need for interventions.Results: In predicting the need for interventions, GBS (AUC = 0.727) and mGBS (AUC = 0.733) outperformed Pre-E RS (AUC = 0.564, P < 0.0001). In predicting 30-day mortality, Pre-E RS (AUC = 0.929) outperformed GBS (AUC = 0.664, P < 0.0001) and mGBS (AUC = 0.652, P < 0.0001). Based on AUC analyses of sensitivities and specificities, the optimal cutoff mGBS and GBS for the need for interventions was 9 (70.71% sensitivity, 89.35% specificity) and 9 (73.57% sensitivity, 82.90% specificity) respectively, and optimal cutoff Pre-E RS for 30-day mortality was 4 (88.0% sensitivity, 97.52% specificity).Conclusions: GBS and mGBS are considered to be moderately accurate in making an early decision about the need of interventions in patients with UGIB. Pre-E RS is considered to be highly accurate in early detection of patients at high risk for 30-day mortality without endoscopic findings. In addition, we suggested potential cutoff scores to predict the need of interventions for GBS and mGBS, and 30-day mortality for Pre-E RS. Further studies are needed to confirm the clinical applicability of results. [ABSTRACT FROM AUTHOR]

Aim: To clarify the efficacy of proton pump inhibitors (PPIs) after endoscopic variceal obturation (EVO) with N-butyl-2-cyanoacrylate., Methods: A retrospective study was performed on 16 liver cirrhosis patients with gastric variceal bleeding that received EVO with injections of N-butyl-2-cyanoacrylate at a single center (Kyung Hee University Hospital at Gangdong) from January 2008 to December 2012. Medical records including patient characteristics and endoscopic findings were reviewed. Treatment results, liver function, serum biochemistry and cirrhosis etiology were compared between patients receiving PPIs and those that did not. Furthermore, the rebleeding interval was compared between patients that received PPI treatment after EVO and those who did not., Results: The patient group included nine males and seven females with a mean age of 61.8 ± 11.7 years. Following the EVO procedure, eight of the 12 patients that received PPIs and three of the four non-PPI patients experienced rebleeding. There were no differences between the groups in serum biochemistry or patient characteristics. The rebleeding rate was not significantly different between the groups, however, patients receiving PPIs had a significantly longer rebleeding interval compared to non-PPI patients (22.2 ± 11.2 mo vs 8.5 ± 5.5 mo; P = 0.008). The duration of PPI use was not related to the rebleeding interval. A total of six patients, who had ulcers at the injection site, exhibited a shorter rebleeding interval (16.8 ± 5.9 mo) than patients without ulcers (19.9 ± 3.2 mo), though this difference was not statistically significant., Conclusion: PPI therapy can extend the rebleeding interval, and should therefore be considered after EVO treatment for gastric varices.