The Prognostic Utilities of DNA Mismatch Repair Status and KRAS and BRAF Mutation in Korean Colorectal Cancer Patients: The KASID Multicenter Study.

INTRODUCTION: KRAS, BRAF, and DNA mismatch repair (MMR) mutations aid clinical decision-making for colorectal cancer (CRC) patients. To ensure accurate predictions, the prognostic utilities of these biomarkers and their combinations must be individualized for patients with various TNM stages. METHODS: Here, we retrospectively analyzed the clinicopathological features of 904 Korean CRC patients who underwent CRC surgery in three teaching hospitals from 2011 to 2013; we also assessed the prognostic utilities of KRAS, BRAF, and MMR mutations in these patients. RESULTS: The overall frequencies of KRAS and BRAF mutations were 35.8% and 3.2%, respectively. Sixty-nine patients (7.6%) lacking expression of ≥1 MMR protein were considered MMR protein deficient (MMR-D); the remaining patients were considered MMR protein intact. KRAS mutations constituted an independent risk factor for shorter overall survival (OS) in TNM stage I-IV and stage III patients. BRAF mutations were associated with shorter OS in TNM stage I-IV patients. MMR-D status was strongly positive prognostic in TNM stage I-II patients. DISCUSSION/CONCLUSION: To our knowledge, this is the first multicenter study to explore the prognostic utilities of KRAS, BRAF, and MMR statuses in Korean CRC patients. Various combinations of KRAS, BRAF, and DNA MMR mutations serve as genetic signatures that affect tumor behavior; they are prognostic in CRC patients.

Clinical importance of weight gain and associated factors in patients with moderate to severe ulcerative colitis: results from the MOSAIK cohort in Korea.

BACKGROUND: Many patients with ulcerative colitis (UC) gain weight after treatment. However, the clinical significance of weight gain in these patients remains unclear. This study aimed to evaluate body weight changes after treatment in patients newly diagnosed with moderate-to-severe UC and their effects on patients' prognosis. METHODS: The change in weight between diagnosis and 1 year after treatment in 212 patients enrolled in the MOSAIK cohort (mean age, 40 years; males, 60%) was analyzed. Significant weight gain was defined as a weight increase of ≥ 5% from the baseline at 1 year. Factors associated with significant weight gain and the effect of significant weight gain on the risk of major adverse outcomes (clinical relapse, hospitalization, and new use of steroids or biologics) during a follow-up period of 20 months were evaluated. RESULTS: Mean weight gain at 1 year was 1.7 ± 4.2 kg. The proportion of overweight/obese patients increased by 9.0% from 37.9% to 46.9%. Thirty-two percent had significant weight gain; extensive colitis at diagnosis was the only factor associated with significant weight gain (odds ratio 6.5, 95% confidence interval 1.4-31.0, p = 0.006). In multivariable analysis, significant weight gain was not associated with the risk of major adverse outcomes. Weight loss symptoms at diagnosis were associated with an increased risk for new steroid use after 1 year. CONCLUSIONS: Approximately one-third of patients with moderate-to-severe UC had significant weight gain after 1 year of treatment. However, significant weight gain was not associated with the patient's prognosis.

Interobserver Variation of Bowel Preparation for Colonoscopy.

BACKGROUD/AIMS: Several bowel preparation scales have been developed, but they are variably validated to guide clinical practice. The aim of this study was to assess the interobserver reliability between internal and external endoscopists using the Harefield Cleaning Scale (HCS). METHODS: Data was collected from a study evaluating the efficacy of oral sulfate tablets in patients undergoing colonoscopy. The assessments of bowel cleansing were carried out by four internal endoscopists at the time of the procedure, and colonoscopy video recordings were reviewed independently by three external endoscopists. Interobserver reliability was quantified using Cohen's Kappa coefficient, and scores and grades of each segment were compared between internal and external endoscopist groups. RESULTS: Among 83 colonoscopy videos, interobserver reliability yielded a fair agreement between internal and external endoscopists, with a Cohen's Kappa coefficient of 0.39 (95% CI 0.08-0.70). Successful overall preparation rates (100% vs 98.8%) and high-quality preparation rates (88% vs 94%) were excellent and comparable between the two groups. In contrast, one case of unsuccessful cleansing (grade C) was documented, only in the external group. In addition, the interobserver reliability between internal and external endoscopists comparing each segmental score yielded a slight agreement in the descending colon (0.11, 95% CI - 0.02 to 0.23) and sigmoid colon (0.04, 95% CI - 0.18 to 0.26). DISCUSSION: Interobserver reliability between internal and external endoscopists using the HCS was fair. However, the HCS may be limited as a reliable scale for assessing bowel preparation quality in the left colon, where liquid is mainly retained in the left lateral position.

Single-Cell Network-Based Drug Repositioning for Discovery of Therapies against Anti-Tumour Necrosis Factor-Resistant Crohn's Disease.

Primary and secondary non-response affects approximately 50% of patients with Crohn's disease treated with anti-tumour necrosis factor (TNF) monoclonal antibodies. To date, very little single cell research exists regarding drug repurposing in Crohn's disease. We aimed to elucidate the cellular phenomena underlying resistance to anti-TNF therapy in patients with Crohn's disease and to identify potential drug candidates for these patients. Single-cell transcriptome analyses were performed using data (GSE134809) from the Gene Expression Omnibus and Library of Integrated Network-Based Cellular Signatures L1000 Project. Data aligned to the Genome Reference Consortium Human Build 38 reference genome using the Cell Ranger software were processed using the Seurat package. To capture significant functional terms, gene ontology functional enrichment analysis was performed on the marker genes. For biological analysis, 93,893 cells were retained (median 20,163 genes). Through marker genes, seven major cell lineages were identified: B-cells, T-cells, natural killer cells, monocytes, endothelial cells, epithelial cells, and tissue stem cells. In the anti-TNF-resistant samples, the top 10 differentially expressed genes were HLA-DQB-1, IGHG1, RPS23, RPL7A, ARID5B, LTB, STAT1, NAMPT, COTL1, ISG20, IGHA1, IGKC, and JCHAIN, which were robustly distributed in all cell lineages, mainly in B-cells. Through molecular function analyses, we found that the biological functions of both monocyte and T-cell groups mainly involved immune-mediated functions. According to multi-cluster drug repurposing prediction, vorinostat is the top drug candidate for patients with anti-TNF-refractory Crohn's disease. Differences in cell populations and immune-related activity within tissues may influence the responsiveness of Crohn's disease to anti-TNF agents. Vorinostat may serve as a promising novel therapy for anti-TNF-resistant Crohn's disease.

Enrichment of Activated Fibroblasts as a Potential Biomarker for a Non-Durable Response to Anti-Tumor Necrosis Factor Therapy in Patients with Crohn's Disease.

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.

Improving the tolerability and safety of 1-L polyethylene glycol plus low-dose ascorbic acid for bowel preparation in a healthy population: a randomized multicenter clinical trial.

BACKGROUND AND AIMS: One-liter polyethylene glycol plus ascorbic acid (PEG-ASC) improves patient tolerability, but some patients still show low tolerability to a relatively high content of ASC. This study aimed to improve the tolerability and safety of 1-L PEG with low-dose ASC in comparison with standard 1-L and 2-L PEG-ASC. METHODS: This was a randomized, controlled, double-blinded, multicenter, noninferiority trial involving 215 healthy adults who underwent colonoscopy from June 2020 to January 2021. Efficacy, tolerability, and safety were compared among 1-L PEG with low-dose ASC (50% lower ASC concentration in group A and 25% lower ASC concentration in groups B and C) and standard 1-L and 2-L PEG-ASC with all split regimens. RESULTS: One-liter PEG with low-dose ASC (groups A-C) had similar bowel cleansing efficacies according to the Harefield Cleansing Scale and Boston Bowel Preparation Scale, without negative clinical performance, compared with standard 1-L and 2-L PEG-ASC preparation (all P > .1). One-liter PEG with low-dose ASC had better tolerability compared with 2-L PEG-ASC and less residual fluid retention in the stomach compared with 1-L PEG-ASC, proportional to the amount of ASC. No significant differences were found in the incidences of overall adverse events, mild adverse events, or death or in the occurrence of gastroduodenal erosion or ulcer in upper endoscopy. CONCLUSIONS: One-liter PEG with low-dose ASC (25%-50% reduction in dose) for bowel cleansing showed similar efficacy and safety compared with standard 1-L or 2-L PEG-ASC, better tolerability compared with 2-L PEG-ASC, and less residual gastric fluid retention compared with standard 1-L PEG-ASC. (Clinical trial registration number: KCT0005490.).

1 L- versus 2 L-polyethylene glycol with ascorbic acid for bowel preparation in elderly patients: a randomized multicenter study.

BACKGROUND: 1 L-polyethylene glycol (PEG)/ascorbic acid (Asc) was developed to reduce the required oral preparation volume through increasing osmotic load through containing a greater quantity of ascorbate components. We aimed to compare the efficacy, tolerability, and safety of a split-dosing regimen of 1 L-PEG/Asc versus 2 L-PEG/Asc in elderly patients undergoing scheduled colonoscopy. METHODS: This was a prospective, non-inferiority, randomized, investigator-blinded multicenter study conducted in Korea between July 2019 and December 2020. Patients aged between 65 and 85 years were randomized at a ratio of 1:1 to either the 1 L-PEG/Asc or 2 L-PEG/Asc group. The efficacy of the bowel preparation was evaluated using the Harefield Cleansing Scale (HCS) and the Boston Bowel Preparation Scale (BBPS). RESULTS: A total of 202 patients were analyzed. Successful overall bowel preparation was similar between the 1 L-PEG/Asc and 2 L-PEG/Asc groups based on HCS (95.1% vs. 93.1%, P = 0.528) and BBPS (93.1% vs. 90.0%, P = 0.422). The perfect overall bowel preparation rate in the 1 L-PEG/Asc group was higher than that in the 2 L-PEG/Asc group (HCS, 40.2% vs. 25.0%, P = 0.021; BBPS, 80.4% vs. 68.0%, P = 0.044). There were more high-quality bowel preparations for the right colon in the 1 L-PEG/Asc group (HCS, 46.1% vs. 30.0%, P = 0.019; BBPS, 83.3% vs. 70.0%, P = 0.025). The adenoma detection rate (47.1% vs. 49.0%, P = 0.782), rate of adverse events (25.5% vs. 23.0%, P = 0.680), shifts in laboratory results, and tolerability were comparable between the groups. CONCLUSION: 1 L-PEG/Asc was as effective, safe, and tolerable as 2 L-PEG/Asc in elderly patients with comorbidities.

Second Victim Experience and Perception Discordance of the Colonoscopic Perforation.

BACKGROUND: Perforation is the most serious adverse event of colonoscopy, but rarely considered from the view of colonoscopists' second victim experience and perception discordance between colonoscopists and patients. AIMS: We aimed to evaluate colonoscopists' second victim experience and the perception discordance between colonoscopists and patients for the colonoscopic perforation. METHODS: A survey for colonoscopic perforation was performed for the colonoscopists and outpatients who visited the university hospital between February 1, 2020, and April 30, 2020. The questionnaire included questions regarding colonoscopists' satisfaction for the intervention strategies offered to patients and patient-colonoscopist perception on colonoscopic perforation. A modified Korean version of the "Second Victim Experience and Support Tool (K-SVEST)" was used to assess the second victim experiences and supportive resources for the colonoscopists. RESULTS: Survey results from 160 colonoscopists and 165 patients were analyzed. The colonoscopists' satisfaction scores were higher for strategies related to sufficient explanation, empathy, courteous listening, and monetary compensation. The scores of the K-SVEST for the second victim experience were highest in psychological distress, followed by loss of professional self-efficacy, colleague support, physical distress, non-work-related support, institutional support, and turnover intentions/absenteeism. Significant patient-colonoscopist discordance was noted for the same colonoscopic perforation scenario on the judgment of medical error, health professionals' apology, monetary compensation, and criminal penalties for the colonoscopists. CONCLUSIONS: Colonoscopists can suffer emotionally and physically from the second victim experience after colonoscopic perforation. In addition, the significant patient-colonoscopist discordance should be considered to make a better communication for the colonoscopic perforation.

Risk of malignancy in kidney transplant recipients: a nationwide population-based cohort study.

BACKGROUND: Post-transplant malignancy is major morbidity complicated in kidney transplantation (KT). In Korea, a few studies have investigated the sex- and age-dependent risk for post-transplant malignancy among KT recipients on a large scale. METHODS: We utilized a national health insurance database in Korea to investigate the relative risk of post-transplant malignancy in 12,634 KT recipients between 2007 and 2017. The same number of patients with acute appendicitis was included as a control group. The relative risk of malignancy was estimated using a multivariable-adjusted Cox model, and interaction analysis was performed to investigate age- and sex-predominant patterns. RESULTS: KT recipients had an overall 1.8-fold higher risk for post-transplant malignancy with an increased risk for 14 of 29 cancer types, among which Kaposi's sarcoma, non-Hodgkin's lymphoma, kidney, uterus, and bladder/urinary tract cancers were most prominent. Although the overall risk for post-transplant malignancy was similar between male and female KT recipients, head and neck cancer had a higher risk among male KT recipients, whereas non-Hodgkin's lymphoma and bladder/urinary tract cancer had a higher risk among female KT recipients. Overall, the young (< 50 years) KT recipients had a higher risk for post-transplant malignancy than older ones (≥ 50 years), whose pattern was most prominent in non-Hodgkin's lymphoma. In contrast, breast and nonmelanoma skin cancer showed a higher risk among older KT recipients. CONCLUSION: KT recipients had an increased risk for a wide range of cancer types, some of which showed differential risk patterns with age and sex. Our result suggests that focused screening for predominant post-transplant malignancies may be an effective strategy for selected KT recipients.

Artificial intelligence-based measurement outperforms current methods for colorectal polyp size measurement.

OBJECTIVES: An accurate polyp size estimation during colonoscopy is crucial to determine the surveillance interval and predict the risk of malignant progression. However, there is a high degree of subjectivity in estimating polyp size among endoscopists in clinical practice. We aimed to assess the efficacy of a novel method that uses artificial intelligence (AI) to measure the size of colon polyps and compare it with current approaches. METHODS: Using the W-Net model for vessel segmentation and based on retinal image datasets (DRIVE, STARE, CHASE-DB, and HRF) and colonoscopy images, we developed the bifurcation-to-bifurcation (BtoB) distance measuring method and applied it to endoscopic images. Measurements were compared with those obtained by eight endoscopists (four expert and four trainees). Diagnostic ability and reliability were evaluated using Lin's concordance correlation coefficients (CCCs) and Bland-Altman analyses. RESULTS: For both experts and trainees, visually estimated sizes of the same polyp were significantly inconsistent depending on the camera view used (P < 0.001). Bland-Altman analyses showed that there was a trend toward underestimation of the sizes of the polyps in both groups, especially for polyps larger than 10 mm. The new technique was highly accurate and reliable in measuring the size of colon polyp (CCC, 0.961; confidence interval 0.926-0.979), clearly outperforming the visual estimation and open biopsy forceps methods. CONCLUSION: The new AI measurement method improved the accuracy and reliability of polyp size measurements in colonoscopy images. Incorporating AI might be particularly important to improve the efficiency of trainees at estimating polyp size during colonoscopy.

Seasonal variations in the diagnosis of the top 10 cancers in Korea: A nationwide population-based study using a common data model.

BACKGROUND AND AIM: A better understanding of seasonal variations in cancer diagnosis may be the first step toward optimal resource distribution in the National Cancer Screening Program (NCSP). This study aimed to identify seasonal variations in the diagnosis of the top 10 major cancers in Korea. METHODS: We conducted a retrospective, observational cohort study in participants aged ≥ 20 years between 2012 and 2016 from the Health Insurance Review and Assessment-National Patient Sample database, previously converted to a common data model. We assessed the overall seasonal variations in the 10 major cancers. RESULTS: We analyzed the following top 10 cancers: stomach (n = 3435), colorectal (n = 5368), liver (n = 7605), pancreatic (n = 2946), gallbladder (n = 899), lung (n = 1598), prostate (n = 2897), thyroid (n = 1966), breast (n = 1313), and kidney (n = 668) cancers. All cancers showed similar seasonal variations in diagnosis, with a significant winter peak. A winter peak in diagnosis was observed for NCSP-covered cancers, such as stomach, colon, liver, and breast cancers, as well as other cancers not covered by the NCSP. The winter peak for cancer diagnosis was the highest for breast cancer (74.4%) followed by thyroid (51.0%) and stomach cancers, whereas it was the lowest for pancreatic cancer followed by prostate and colorectal cancers. CONCLUSIONS: Significant seasonal variations were found in the diagnosis of the top 10 major cancers, with a winter peak, which may be explained by the participants' behavior pattern with respect to the NCSP. Our findings suggest that trading off of NCSP healthcare resources between winter and other seasons may be beneficial.

Early course of newly diagnosed moderate-to-severe ulcerative colitis in Korea: Results from a hospital-based inception cohort study (MOSAIK).

BACKGROUND AND AIM: No inception cohort study has ever evaluated the early course of moderate-to-severe ulcerative colitis (UC) within 1 year of diagnosis in the non-Caucasian population. We aimed to investigate the early clinical course of moderate-to-severe UC patients in terms of remission, relapse, UC-related hospitalizations, colectomy, mortality, and overall use of medications. METHODS: In the MOSAIK inception cohort, which is an ongoing multicenter, prospective, hospital-based, observational cohort, 354 patients with moderate-to-severe UC were followed up for 1 year. Main outcomes of UC and predictive factors for medication use over the course of 1 year were evaluated. RESULT: Among 354 patients, 276 (78.0%) patients were followed up for 1 year. The rates of remission, relapse, UC-related hospitalizations, and proximal disease extension were 95.3%, 39.6%, 15.2%, and 12.3%, respectively. Systemic corticosteroids, thiopurines, and biologics were administered to 61.2%, 30.4%, and 10.5% of patients, respectively, throughout 1 year. One year after, 58.2% patients experienced remission or mild endoscopic activity. Overall disease courses did not show much difference according to moderate or severe disease activity at baseline. In addition, no colectomy and mortality were observed for 1 year. Predictive factors for medication use included disease severity, disease extent, endoscopic severity, and presence of periappendiceal inflammation at baseline for corticosteroid, disease extent and initial corticosteroid use for thiopurine, and only initial corticosteroid use for biologics. CONCLUSION: Korean patients with moderate-to-severe UC may have more favorable early outcomes than Western patients. However, outcomes of them need to be further looked into for a longer time.

Real-World Use of Colonoscopy in an Older Population: A Nationwide Standard Cohort Study Using a Common Data Model.

BACKGROUNDS AND AIMS: Rapid population aging is considered to be a major factor in increased colonoscopy use in Korea. However, real-world use of colonoscopy in older populations is rarely evaluated using Korean databases. METHODS: We conducted a retrospective, observational cohort study of individuals aged over 20 years between 2012 and 2017. We used the Health Insurance Review and Assessment-National Patient Samples database, previously converted to the standardized Observational Medical Outcomes Partnership-Common Data Model. The use of diagnostic colonoscopy and colonoscopic polypectomy was evaluated, stratified by age group and sex. RESULTS: During the study period, we captured data from the database on 240,406 patients who underwent diagnostic colonoscopy and 88,984 who underwent colonoscopic polypectomy. During the study period, use of diagnostic colonoscopy and colonoscopic polypectomy steadily increased, but both procedures were most significantly increased in the 65- to 85-year group compared to other age groups (p < 0.05). Average ages for both procedures significantly increased in the most recent 3 years (p < 0.05). Polypectomy rates for men plateaued in the 50- to 64-year age group, but rates for women steadily increased up to the 65- to 85-year group. Polypectomy rates were higher for men than for women in all index years. CONCLUSIONS: The use of diagnostic colonoscopy and colonoscopic polypectomy significantly increased in the 65- to 85-year age group. Our findings suggest that more available colonoscopy resources should be allocated to older populations, considering the aging society in Asian countries.

Usefulness of narrow-band imaging for the detection of remnant sessile-serrated adenoma (SSA) tissue after endoscopic resection: the KASID multicenter study.

BACKGROUND: A sessile-serrated adenoma (SSA) has a high risk for incomplete resection. Little is known regarding how to immediately detect remnant SSA tissue after endoscopic resection. We investigated the usefulness of narrow-band imaging (NBI) to detect remnant SSA tissue after endoscopic mucosal resection (EMR). METHODS: We performed a prospective randomized study on 138 patients who had suspicious SSA on colonoscopy at five centers. After EMR on the suspected SSA determined on the endoscopic morphology, all lesions were randomized into two inspection methods, NBI and white light endoscopy (WLE), to detect remnant tissue on the resected margin. If remnant tissue was detected, an additional resection was performed. Finally, we obtained quadrant biopsies on the resection margin to evaluate the incomplete resection. The proportion of incomplete resection was calculated by combining the detection of remnant tissue and the positivity of SSA cells on the final quadrant biopsies. The primary outcome was the proportion of remnant tissue detection, and the secondary outcome was the proportion of incomplete resection of SSA. RESULTS: In all, 145 lesions from 138 patients were removed. The diagnostic rate of SSA was 87.6% (127/145). After randomization, NBI inspection was performed on 69 lesions, and WLE inspection was performed on 76 lesions. The histologic diagnostic rate of SSA was 89.9% (62/69) in the NBI group and 85.5% (65/76) in the WLE group (p > 0.05). There were no significant differences in the detection of remnant tissue (12.9% (8/62) vs. 15.4% (10/65), p > 0.05), the proportion of SSA in remnant tissue (11.3% (7/62) vs. 12.3% (8/65), p > 0.05), or the proportion of incomplete resection (6.5 (4/62) vs. 10.8 (7/65), p > 0.05) between the NBI and WLE inspection groups, respectively. CONCLUSION: NBI was not superior to WLE for detecting remnant SSA tissue after EMR and could not decrease the proportion of incomplete resection of SSA.

Pretreatment with Ranitidine Bismuth Citrate May Improve Success Rates of Helicobacter pylori Eradication: A Prospective, Randomized, Controlled and Open-Label Study.

Effective Helicobacter pylori (H. pylori) eradication is a major public health concern; however, eradication failure rates with the standard triple therapy remain high. We aimed to investigate the effectiveness and tolerability of ranitidine bismuth citrate (RBC) pretreatment before standard triple therapy for H. pylori eradication. A prospective, randomized, controlled, and open-label clinical trial was conducted from June to December 2019. H. pylori eradication rate, safety, and tolerability were compared between the standard treatment group (esomeprazole, amoxicillin, and clarithromycin for 7 days) and RBC pretreatment group (RBC for 2 weeks before standard triple therapy). This trial ended earlier than estimated owing to the N-nitrosodimethylamine concerns with ranitidine. Success rates of H. pylori eradication were 80.9% and 67.3% in the RBC pretreatment (n = 47) and standard treatment (n = 52) (p = 0.126) groups, respectively. Our trial was discontinued earlier than planned; however, a statistical significance would be achieved by expansion of our data (p = 0.031) if patient enrollment numbers reached those initially planned. Adverse event rates were comparable between groups (25.5% in the pretreatment group vs. 28.8% in the standard treatment group), without serious event. Tolerability was excellent in both groups, recorded as 97.9% and 100% in the pretreatment and standard treatment groups, respectively. Compared with the standard triple regimen, RBC pretreatment for 2 weeks may achieve higher H. pylori eradication rates, with excellent safety and tolerability. However, this study necessitates further validation as it was discontinued early owing to the N-nitrosodimethylamine issues of ranitidine.

Long-term prognosis of ulcerative colitis and its temporal changes between 1986 and 2015 in a population-based cohort in the Songpa-Kangdong district of Seoul, Korea.

OBJECTIVE: No population-based study has evaluated the natural course of UC over three decades in non-Caucasians. We aimed to assess the long-term natural course of Korean patients with UC in a population-based cohort. DESIGN: This Korean population-based, Songpa-Kangdong IBD cohort included all patients (n=1013) newly diagnosed with UC during 1986-2015. Disease outcomes and their predictors were evaluated. RESULTS: During the median follow-up of 105 months, the overall use of systemic corticosteroids, thiopurines and antitumour necrosis factor (anti-TNF) agents was 40.8%, 13.9% and 6.5%, respectively. Over time, the cumulative risk of commencing corticosteroids decreased, whereas that of commencing thiopurines and anti-TNF agents increased. During follow-up, 28.7% of 778 patients with proctitis or left-sided colitis at diagnosis experienced proximal disease extension. A total of 28 patients (2.8%) underwent colectomy, demonstrating cumulative risks of colectomy at 1, 5, 10, 20 and 30 years after diagnosis of 1.0%, 1.9%, 2.2%, 5.1% and 6.4%, respectively. Multivariate Cox regression analysis revealed that extensive colitis at diagnosis (HR 8.249, 95% CI 2.394 to 28.430), ever use of corticosteroids (HR 6.437, 95% CI 1.440 to 28.773) and diagnosis in the anti-TNF era (HR 0.224, 95% CI 0.057 to 0.886) were independent predictors of colectomy. The standardised mortality ratio in patients with UC was 0.725 (95% CI 0.508 to 1.004). CONCLUSION: Korean patients with UC may have a better clinical course than Western patients, as indicated by a lower colectomy rate. The overall colectomy rate has continued to decrease over the past three decades.

Association between the National Cancer Screening Programme (NSCP) for gastric cancer and oesophageal cancer mortality.

BACKGROUND: The aim was to evaluate whether this gastric cancer-screening programme was effective in reducing oesophageal cancer mortality. METHODS: A population-based retrospective cohort study was conducted using the Korean National Cancer Screening Programme (NCSP) database. The study cohort comprised 16,969 oesophageal cancer patients who had been diagnosed in 2007-2014. We analysed the association between the history of NSCP for gastric cancer and oesophageal cancer mortality. RESULTS: Compared with never-screened subjects, ever-screened subjects had an overall HR for oesophageal cancer mortality of 0.647 (95% CI, 0.617-0.679). According to the time interval since screening, the HRs of death were 0.731 (95% CI, 0.667-0.801) for 6-11 months, 0.635 (95% CI, 0.594-0.679) for 12-23 months, 0.564 (95% CI, 0.522-0.610) for 24-35 months and 0.742 (95% CI, 0.679-0.810) for ≥36 months. According to the last screening modality, the HRs of death were 0.497 (95% CI, 0.464-0.531) for upper endoscopy, and 0.792 (95% CI, 0.749-0.838) for UGIS. Upper endoscopy reduced the mortality consistently in all age groups over 50 years, whereas UGIS could not. CONCLUSION: The NCSP for gastric cancer was effective in reducing the mortality of oesophageal cancer, and upper endoscopy was superior to UGIS.

Correction: Association between the National Cancer Screening Programme (NSCP) for gastric cancer and oesophageal cancer mortality.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cap-Assisted Chromoendoscopy Using a Mounted Cap Versus Standard Colonoscopy for Adenoma Detection.

OBJECTIVES: Some neoplastic lesions remain undetected on colonoscopy. To date, no studies have investigated whether combining cap-assisted colonoscopy with chromoendoscopy increases the adenoma detection rate (ADR). This study aimed to compare cap-assisted chromoendoscopy (CAP/CHROMO) with standard colonoscopy (SC) with respect to their efficacy in detecting adenomas. METHODS: This prospective, multicenter, randomized controlled trial included asymptomatic subjects aged 45-75 years who underwent colonoscopy for the first time at 14 university hospitals. Subjects were randomized to either the CAP/CHROMO group (with 0.09% indigo carmine spraying using a cap-mounted catheter at the tip of the colonoscope) or the SC group. All polyps were resected, but only histologically confirmed neoplastic lesions were considered for analysis. The primary outcome was ADR, defined as the proportion of subjects with at least 1 adenoma. RESULTS: A total of 1,905 subjects were randomized to the CAP/CHROMO (n = 948) or SC (n = 957) group at 14 centers. Subjects' demographic characteristics were similar between both groups. The CAP/CHROMO group had significantly higher ADR than the SC group (54.4% vs 44.9%, P < 0.001). Significantly, more subjects with at least 1 proximal colon adenoma were identified by CAP/CHROMO (38.6%) than by SC (31.2%) (P = 0.001). The proximal serrated polyp detection rate by CAP/CHROMO was significantly higher in the female subgroup vs SC. However, advanced ADR was not different between the CAP/CHROMO and SC groups (9.3% vs 7.6%, P = 0.180). DISCUSSION: CAP/CHROMO markedly improved the ADR and enhanced the detection of proximal adenoma. CAP/CHROMO is feasible for routine application and will allow for a more effective surveillance program.

Nationwide validation study of diagnostic algorithms for inflammatory bowel disease in Korean National Health Insurance Service database.

BACKGROUND AND AIM: We conducted a nationwide validation study of diagnostic algorithms to identify cases of inflammatory bowel disease (IBD) within the Korea National Health Insurance System (NHIS) database. METHOD: Using the NHIS dataset, we developed 44 algorithms combining the International Classification of Diseases (ICD)-10 codes, codes for Rare and Intractable Diseases (RID) registration and claims data for health care encounters, and pharmaceutical prescriptions for IBD-specific drugs. For each algorithm, we compared the case identification results from electronic medical records data with the gold standard (chart-based diagnosis). A multiple sampling test verified the validation results from the entire study population. RESULTS: A random nationwide sample of 1697 patients (848 potential cases and 849 negative control cases) from 17 hospitals were included for validation. A combination of the ICD-10 code, ≥ 1 claims for health care encounters, and ≥ 1 prescription claims (reference algorithm) achieved excellent performance (sensitivity, 93.1% [95% confidence interval 91-94.7]; specificity, 98.1% [96.9-98.8]; positive predictive value, 97.5% [96.1-98.5]; negative predictive value, 94.5% [92.8-95.8]) with the lowest error rate (4.2% [3.3-5.3]). The multiple sampling test confirmed that the reference algorithm achieves the best performance regarding IBD diagnosis. Algorithms including the RID registration codes exhibited poorer performance compared with that of the reference algorithm, particularly for the diagnosis of patients affiliated with secondary hospitals. The performance of the reference algorithm showed no statistical difference depending on the hospital volume or IBD type, with P-value < 0.05. CONCLUSIONS: We strongly recommend the reference algorithm as a uniform standard operational definition for future studies using the NHIS database.