Effective Endoscopic Submucosal Dissection of a Huge Esophageal Liposarcoma: A Case Report.

This case report presents the successful endoscopic submucosal dissection (ESD) of a well-differentiated esophageal liposarcoma in a 51-year-old male with persistent dysphagia. The cause was initially diagnosed as a 10 cm pedunculated lesion extending from the upper esophageal sphincter to the mid-esophagus. An ESD was chosen over traditional surgery because it is less invasive. The procedure involved a precise submucosal injection and excision with special techniques to manage bleeding from a central vessel. Despite the extraction challenges owing to the size of the lesion, it was successfully removed orally. A histopathological examination of the 8.3×4.2×2.3 cm specimen revealed the characteristic features of a well-differentiated liposarcoma, including MDM2 and CDK4 positivity. The follow-up revealed no recurrence, and active surveillance has been performed since. This report highlights the versatility of ESD in treating significant esophageal tumors and provides evidence for its efficacy as a minimally invasive alternative.

[IDEN Consensus on Management of Antithrombotic Agents in Patients Undergoing Gastrointestinal Endoscopy].

Antithrombotic agents, including antiplatelet agent and anticoagulants are widely used in Korea due to increasing incidence of cardio-cerebrovascular disease and aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. Clinical practice guideline regarding this issue which was developed by the Korean Society of Gastrointestinal Endoscopy was published in 2020. However, since then, new evidence has emerged for the use of dual antiplatelet therapy and direct anticoagulant management, and revised guidelines were issued in the US and Europe. Accordingly, the previous guidelines were revised, cardiologists also participated in the development group, and the recommendations went through a consensus process among international experts. This guideline presents 14 recommendations made according to the Grading of Recommendations, Assessment, Development, and Evaluation methodology, and was reviewed by multidisciplinary experts. This guideline provides useful information that can assist endoscopists in the management of patients on antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

International Digestive Endoscopy Network consensus on the management of antithrombotic agents in patients undergoing gastrointestinal endoscopy.

Antithrombotic agents, including antiplatelet agents and anticoagulants, are widely used in Korea because of the increasing incidence of cardiocerebrovascular disease and the aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. The clinical practice guidelines for this issue, developed by the Korean Society of Gastrointestinal Endoscopy, were published in 2020. However, new evidence on the use of dual antiplatelet therapy and direct anticoagulant management has emerged, and revised guidelines have been issued in the United States and Europe. Accordingly, the previous guidelines were revised. Cardiologists were part of the group that developed the guideline, and the recommendations went through a consensus-reaching process among international experts. This guideline presents 14 recommendations made based on the Grading of Recommendations, Assessment, Development, and Evaluation methodology and was reviewed by multidisciplinary experts. These guidelines provide useful information that can assist endoscopists in the management of patients receiving antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy.

With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Efficacy and safety of CKD-495 in acute and chronic gastritis: A Phase III superiority clinical trial.

BACKGROUND: Despite the availability of numerous treatment options, many patients with gastritis experience only partial symptom relief. CKD-495, a newly developed product with the active ingredient extracted from Cinnamomum cassia Presl., has demonstrated anti-inflammatory and antioxidant activity in vitro and an in vivo protective effect against gastric damage by stimulating mucus secretion. This study compared the efficacy and safety of CKD-495 with Artemisiae argyi folium (AAF) for the treatment of acute and chronic gastritis. AAF, a gastric mucosa protective agent that promotes gastric mucosa regeneration, has been used clinically for about 20 years. METHODS: This phase III multicenter, randomized, double-blind, parallel-group trial (ClinicalTrials.gov; NCT04255589) assigned 242 patients with endoscopically-proven gastric mucosal erosions to receive CKD-495 75 mg (n = 122) or AAF 60 mg (n = 120), respectively, with placebo (for double-blind purposes) 3 times a day for 2 weeks. The primary efficacy endpoint was the erosion improvement rate. Secondary endpoints included erosion cure rates, and improvement rates for edema, redness, hemorrhage, and gastrointestinal (GI) symptoms. Drug-related adverse events were evaluated. RESULTS: The erosion improvement rate was significantly higher in the CKD-495 group than in the AAF group for both the full analysis set (55.9% vs 39.4%, P = .0063) and per-protocol set (54.6% vs 38.2%, P = .0084). In addition, the erosion improvement rate in patients with acute or chronic gastritis showed that the CKD-495 group had better improvement of erosion than the AAF group, especially in patients with chronic gastritis. Analysis of secondary endpoints, which included erosion cure rate and the improvement rates of edema, redness, hemorrhage, and GI symptoms, showed that the CKD-495 group was more effective than the AAF group. There were no significant between-group differences in safety profiles. No serious adverse events or adverse drug reactions occurred. CONCLUSIONS: These results demonstrate that CKD-495 75 mg is superior to AAF 60 mg in terms of the endoscopic improvement rate of erosions in patients with acute or chronic gastritis. This new mucoprotective agent, CKD-495, can be considered the therapy of choice for symptomatic relief and healing of gastritis.

A Gastric Magnetic Foreign Body Incidentally Detected Several Years after Ingestion.

Foreign body ingestion is commonly seen in children. However, occasionally it may also be seen among adults and is often associated with intellectual disability, psychiatric disorders, and alcoholism. Ingestion of a magnetic foreign body may cause complications such as gastrointestinal tract perforation, wherein emergency endoscopic removal of the foreign body is generally required. Here, we report a rare case of a 59-year-old male with an intellectual disability and psychiatric disorder in whom metallic objects in the stomach cavity were accidentally discovered during abdominal CT. Esophagogastroduodenoscopy revealed several metallic objects attached to two magnets, which had been ingested several years before and had remained in the stomach cavity. The magnets and metallic objects were safely removed endoscopically using rat-tooth forceps without complications.

Long-term outcomes of endoscopic resection for duodenal neuroendocrine tumors.

Duodenal neuroendocrine tumors (d-NETs) ≤ 10 mm in size, confined to the submucosal layer, without lymph node or distant metastasis, can be treated safely and effectively by endoscopic management. However, most results are based on limited data and short follow-up outcomes. Herein, we aimed to evaluate the short-term and long-term outcomes of endoscopic resection for d-NETs. We retrospectively analyzed 63 patients with 68 d-NETs who had undergone endoscopic resection at two hospitals between January 2009 and December 2021. En-bloc resection, endoscopically complete resection, and histopathologically complete resection rates were evaluated as short-term outcomes. Furthermore, long-term outcomes were analyzed in 46 patients with 50 d-NETs with a follow-up period of > 1 year. The overall en-bloc, endoscopically complete, and histopathologically complete resection rates were 92.6% (63/68), 100% (68/68), and 69.1% (47/68), respectively. Tumor size (> 5 mm) was the only predictive factor for histopathologically incomplete resection (p = 0.015). The procedure-related bleeding and perforation rates were 0% and 5.9%, respectively. No recurrences were observed in patients with histopathologically complete resection and those with histopathologically incomplete resection at a median follow-up period of 48 months (range 12-132 months). Endoscopic resection for d-NETs ≤ 10 mm in size, limited to the submucosal layer, and without lymph node or distant metastasis provides favorable long-term outcomes when endoscopically complete resection is achieved.

[Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy].

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Risk Factors for Early- and Late-Onset Cholecystitis after Y-Configured Metal Stent Placement in Patients with Malignant Hilar Biliary Obstruction: A Single-Center Study.

This study evaluated the prevalence and risk factors of early- (within 7 days of placement) and late-onset (after 7 days of placement) cholecystitis after Y-configured metal stent placement. Between June 2005 and August 2020, 109 patients who had been treated with Y-configured metal stents for malignant hilar obstruction were enrolled in the study. We retrospectively analyzed the potential risk factors for post-stent cholecystitis. The presence of diabetes (p = 0.042), the length of the common part of the Y-stent (p = 0.017), filling of the gallbladder with contrast medium during the procedure (p = 0.040), and tumor invasion of the cystic duct accompanied by filling the gallbladder with contrast medium during metal stent placement (p = 0.001) were identified as important risk factors. In cases of late-onset cholecystitis, stent obstruction (p = 0.004) and repeated endoscopic procedures due to stent malfunction (p = 0.024) were significant risk factors. In the multivariate logistic regression analysis, significant risk factors were the length of the common part of the Y-stent (p = 0.032) in early-onset cholecystitis and stent obstruction (p = 0.007) in late-onset cholecystitis. This study demonstrated that early-onset cholecystitis may occur in patients according to the length of the common portion of the Y-stent. In contrast, late-onset cholecystitis may occur in patients with stent obstruction.

Clinical practice guidelines for percutaneous endoscopic gastrostomy.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

Feasibility of endoscopic resection and impact of endoscopic ultrasound-based surveillance on colorectal subepithelial tumors.

BACKGROUND: Owing to the rising number of screening endoscopies and instrumental advances in endoscopic ultrasound (EUS), colorectal subepithelial tumors (SETs) are being increasingly detected. We aimed to determine the feasibility of endoscopic resection (ER) and the impact of EUS-based surveillance on colorectal SETs. METHODS: The medical records of 984 patients with incidentally detected colorectal SETs between 2010 and 2019 were retrospectively reviewed. Overall, 577 colorectal SETs underwent ER, and 71 colorectal SETs underwent serial colonoscopy for > 12 months. RESULTS: The mean tumor size (± standard deviation) of 577 colorectal SETs for which ER was performed was 7.0 ± 5.7 (median, 55; range, 1-50) mm; 475 tumors were located in the rectum and 102, in the colon. En bloc resection was achieved in 560/577 treated lesions (97.1%), and complete resection was achieved in 516/577 (89.4%). ER-related adverse events occurred in 15/577 (2.6%) patients. SETs originating from the muscularis propria showed a higher risk of ER-related adverse events and perforation than SETs arising from the mucosal or submucosal layer (odds ratio [OR] 19.786, 95% confidence interval [CI] 4.556-85.919; P = 0.002 and OR 141.250, 95% CI 11.596-1720.492; P = 0.046, respectively). Seventy-one patients were followed up after EUS without any treatment for > 12 months, during which three showed progression; eight, regression; and sixty, no changes. CONCLUSIONS: ER for colorectal SETs showed excellent efficacy and safety. Additionally, colorectal SETs without high-risk features in surveillance with colonoscopy showed an excellent prognosis.

Incidence and adverse clinical events of primary sclerosing cholangitis with ulcerative colitis.

PURPOSE: The aim of this study was to conduct a nationwide population-based study to estimate the incidence of primary sclerosing cholangitis in patients with ulcerative colitis (UC-PSC) and investigate healthcare use, medication use, surgery, cancer, and death as adverse clinical events of UC-PSC. METHODS: We identified incident cases of UC with (UC-PSC) or without PSC (UC-alone) between 2008 and 2018 using health insurance claims data in Korea. Univariate (crude hazard ratio (HR)) and multivariate analyses were performed to compare the risk of adverse clinical events between groups. RESULTS: A total of 14,406 patients with UC using population-based claims data were detected in the cohort. Overall, 3.38% (487/14,406) of patients developed UC-PSC. During a mean follow-up duration of approximately 5.92 years, the incidence of PSC in patients with UC was 185 per 100,000 person-years. The UC-PSC group showed statistically more frequent healthcare use (hospitalization and emergency department visits: HRs, 5.986 and 9.302, respectively; P < .001), higher immunomodulator and biologic use (azathioprine, infliximab, and adalimumab: HRs, 2.061, 3.457, and 3.170, respectively; P < .001), and higher surgery rate (operation for intestinal obstruction, and colectomy: HRs, 9.728 and 2.940, respectively; P < .001) than did the UC-alone group. The UC-PSC group also showed significantly higher colorectal cancer and biliary tract cancer (HRs, 2.799 and 36.343, respectively; P < .001) and mortality (HR, 4.257) rates than did the UC-alone group. CONCLUSION: Patients with UC-PSC have higher risks of colorectal cancer, biliary tract cancer, and death than do patients with UC-alone. Although considered a rare disease, managing this complex and costly disease requires recognition of the impact of increased burden on healthcare services.

Patient-derived Organoid Model for Predicting the Chemoresponse in Patients With Colorectal Cancer.

BACKGROUND/AIM: Cancer mortality has decreased due to the contribution of extensive research on cancer treatment, including chemotherapy, radiation, and immunotherapy. However, histopathologically similar tumors originating from the same organ are treated with identical or similar chemotherapeutic regimens regardless of patient characteristics or cancer subtypes. The aim of this study was to evaluate the utility of organoids in predicting responses to chemotherapeutic agents. PATIENTS AND METHODS: This study retrospectively reviewed patient-derived organoids (PDOs) from 10 colorectal cancer patients to compare chemotherapy responses. Drug sensitivities for 5-fluorouracil (5-FU), cisplatin, oxaliplatin, and irinotecan were compared using GI50 (concentration that inhibits cancer cell growth by 50%). RESULTS: When organoids were treated with 5-FU, GI50 was the lowest compared to the other three chemotherapeutic agents (cisplatin, oxaliplatin, and irinotecan). The responsiveness to chemotherapeutic agents differed depending on specific patient characteristics including age, tumor location, stage, and gross type. The response of the patients' organoids to chemotherapeutic agents was consistent with the response to chemotherapy actually performed in those patients with cancer recurrence after surgery. CONCLUSION: PDOs may be useful as a preclinical model in predicting chemotherapy responses in cancer patients.

Longitudinal trends in direct costs and healthcare utilization ascribable to inflammatory bowel disease in the biologic era: a nationwide, population-based study.

BACKGROUND AND AIM: Biologic-era data regarding the direct cost and healthcare utilization of inflammatory bowel disease at the population level are limited, especially in Asia. Thus, we aimed to investigate the nationwide prevalence, direct cost, and healthcare utilization of inflammatory bowel disease in Korea in a recent 10-year period. METHODS: Using the Korean National Health Insurance claim data from 2008 to 2017, we investigated all prescription medications and their associated direct costs, hospitalizations, and outpatient visits. We also estimated the nationwide prevalence of inflammatory bowel disease using population census data. RESULTS: The estimated inflammatory bowel disease prevalence significantly increased from 108.8/100 000 in 2008 to 140.4/100 000 in 2017. The overall annual costs for inflammatory bowel disease and the healthcare cost per capita increased from $24.5 million (in US dollars) to $105.1 million and from $458.4 to $1456.6 million, respectively (both P < 0.001). Whereas the ratio of outpatient costs increased from 35.3% to 69.4%, that of outpatient days remained steady. The total annual medication cost and proportion rose from $13.3 million to $76.8 million and from 54.2% to 73.3%, respectively, mainly due to the increasing antitumor necrosis factor cost, from $1.5 million to $49.3 million (from 11.1% to 64.1% of the total annual drug cost and from 6.3% to 46.9% of the total annual cost). CONCLUSIONS: We observed increasing trends in the prevalence, direct costs, and healthcare utilization of inflammatory bowel disease in Korea in recent years. The attributable cost was mainly driven by rising expenditures on antitumor necrosis factor medications.

Clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal neuroendocrine tumors: a multicenter, retrospective study of 10-year experience.

BACKGROUND: The efficacy of endoscopic resection for of 10-20 mm rectal neuroendocrine tumor (NET) remains controversial. We aimed to evaluate the clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal NET and to determine the optimal treatment. METHODS: Patients who underwent endoscopic resection for rectal NET in four tertiary hospitals were enrolled, and data on with the clinical outcomes and risk factors related to poor prognosis were retrospectively analyzed. RESULTS: A total of 105 patients who underwent endoscopic submucosal resection (ESD; n = 65, 61.9%), modified endoscopic mucosal resection (mEMR; n = 31, 29.5%), and conventional EMR (cEMR; n = 9, 8.6%) were enrolled. The mean follow-up period was 41.2 ± 21.9 months. In the morphologic findings, the mean diameter was 11.6 mm (range 10-19); the shape was sessile (50.5%) and mixed type (49.5%), and surface depression was observed in 41.9% of patients. In the histologic findings, 87.6% of patients had G1 and 12.4% G2 tumor grade, and 3.8% of patients had lymphovascular invasion. The overall en bloc and histologically complete (R0) resections were 99.1% and 76.2%, respectively. cEMR was a less-frequently developed R0 resection. In the univariate and multivariate analyses for R0 resection, only surface depression was significantly associated. Regional or distant organs metastasis during follow-up developed in three patients (2.9%) and was significantly associated with female sex, redness, G2 tumor grade, and non-ESD methods. CONCLUSION: Patients who underwent endoscopic resection of 10-20 mm rectal NET had good prognosis; therefore, endoscopic resection can be considered as the first-line treatment, particularly for 10-14 mm rectal NET. However, the risk factors, such as female sex, redness, G2 tumor grade and non-ESD methods, were associated with regional or distant metastases during follow-up. Therefore, patients with these risk factors should be carefully monitored.

The effect of biological agent on body composition in patients with Crohn's disease.

BACKGROUND: Crohn's disease (CD) is associated with altered body composition, affecting clinical outcomes. We evaluated the impact of biologics on body composition in CD patients. METHODS: This multicenter longitudinal study across four Korean university hospitals conducted from January 2009 to August 2021 retrospectively reviewed data of CD patients with abdominal computed tomography (CT) before and after the biologic treatment. Skeletal muscle area (SMA), visceral fat area (VFA), and subcutaneous fat area (SFA) of the third lumbar vertebra (L3) on CT were measured. Myopenia was defined as L3 skeletal muscle index (SMI) of < 49 and < 31 cm2/m2 for men and women, respectively. RESULTS: Among 112 participants, 79 (70.5%) had myopenia. In the myopenia group, all body composition parameters were significantly increased after the biologic treatment: SMI (37.68 vs. 39.40 cm2/m2; P < 0.001), VFA (26.12 vs. 54.61 cm2; P < 0.001), SFA (44.29 vs. 82.42 cm2; P < 0.001), while no significant differences were observed in the non-myopenia group. In multivariate analysis, penetrating CD (hazard ratio, 5.40; P = 0.020) was the independent prognostic factor for surgery. Operation-free survival rate tended to decrease in the myopenia group (Log-rank test, P = 0.090). CONCLUSIONS: Biological agents can increase all body composition parameters in CD patients with myopenia. These patients are more likely to experience surgery.

Efficacy and Safety of Infliximab in Intestinal Behçet's Disease: A Multicenter, Phase 3 Study (BEGIN).

Background/Aims: To date, there is no prospective study that specifically investigated the efficacy of infliximab in intestinal Behçet's disease (BD). This study evaluated the efficacy of infliximab in patients with moderate-to-severe active intestinal BD that are refractory to conventional therapies. Methods: This phase 3, interventional, open-label, single-arm study evaluated clinical outcomes of infliximab treatment in patients with moderate-to-severe intestinal BD. The coprimary endpoints were clinical response, decrease in disease activity index for intestinal BD (DAIBD) score ≥20 from weeks 0 to 8 for the induction therapy and week 32 for the maintenance therapy. Results: A total of 33 patients entered the induction therapy and were treated with infliximab 5 mg/kg intravenously at weeks 0, 2, and 6. The mean DAIBD score changed from 90.8±40.1 at week 0 to 40.3±36.4 at week 8, with a significant mean change of 50.5±36.4 (95% confidence interval, 37.5 to 63.4; p<0.001). Thirty-one (93.9%) continued to receive 5 mg/kg infliximab every 8 weeks during the maintenance therapy. The mean change in the DAIBD score after the maintenance therapy was statistically significant (61.5±38.5; 95% confidence interval, 46.0 to 77.1; p<0.001, from weeks 0 to 32). The proportion of patients who maintained a clinical response was 92.3% at week 32. No severe adverse reactions occurred during the induction and maintenance therapies. Conclusions: This study provided evidence that infliximab 5 mg/kg induction and maintenance therapies are efficacious and well-tolerated in patients with moderate-to-severe active intestinal BD. (ClinicalTrials.gov identifier: NCT02505568).

Diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy in upper gastrointestinal subepithelial tumors measuring 2-5 cm in size.

BACKGROUND: Subepithelial tumors (SETs) in the upper gastrointestinal (GI) tract are frequently discovered during upper endoscopy, and their management is determined based on size and histopathological diagnosis. We aimed to evaluate the diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) in upper GI SETs of 2-5 cm in size. METHODS: We included 63 patients who underwent EUS-FNB for upper GI SETs of 2-5 cm in size between January 2013 and February 2020. The diagnostic yield of EUS-FNB, ability of EUS-FNB in discriminating malignant from non-malignant lesions, and histopathological concordance between EUS-FNB specimens and resected specimens were evaluated. RESULTS: Successful acquisition of macroscopic tissue cores was possible in all 63 cases, and the diagnostic yield of EUS-FNB was 92.1% (58/63). The sensitivity, specificity, and accuracy of EUS-FNB in discriminating malignant from non-malignant lesions were 100% (95% confidence interval [CI] 85.3-100%), 87.8% (95% CI 79.9-87.8%), and 92.1% (95% CI 81.8-92.1%), respectively. Of the 26 SETs that were endoscopically or surgically resected after EUS-FNB, the histopathological concordance rate between the EUS-FNB specimens and resected specimens was 100% (24/24), except in two cases of inadequate results with EUS-FNB specimens. CONCLUSION: EUS-FNB provides high diagnostic yield and high capability in discriminating malignant from non-malignant lesions in upper GI SETs of 2-5 cm in size.

Clinical Features and Long-term Prognosis of Crohn's Disease in Korea: Results from the Prospective CONNECT Study.

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.