Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: Although host body composition, nutritional and systemic inflammatory status have been suggested to have an impact on prognosis in patients with colorectal cancer (CRC), their impact on patients with stage IV CRC remains unclear.This study investigated the prognostic effects of those parameters in patients initially diagnosed with stage IV CRC who underwent surgery. Methods: Patients with stage IV CRC who underwent surgery were selected. Preoperative computed tomography images were evaluated for skeletal muscle index, skeletal muscle density (SMD), visceral fat area (VFA), and subcutaneous fat area (SFA). For nutritional status and systemic inflammation, prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) were used. The Cox proportional hazard model was used to evaluate the prognostic significance of progression-free survival (PFS) after adjustment for the other covariates in the model. Results: Data of 134 patients with stage IV CRC who underwent surgery between January 2005 and February 2014 were included. SMD, VFA, SFA, PNI, NLR, LMR, and PLR were associated with PFS in the univariable analysis. In the multivariable analysis, SFA (hazard ratio [HR], 0.612; 95% confidence interval [CI], 0.389–0.961; P = 0.033), and PNI (HR, 0.536; 95% CI, 0.345–0.832; P = 0.005) were identified to be independent prognostic factors for PFS. Conclusion SFA and PNI both demonstrated prognostic significance in patients with stage IV CRC. Accordingly, we believe further studies are warranted to determine whether incorporating these factors can aid in surgical decision-making for stage IV CRC patients.

Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Purpose: Atypical hyperplasia (AH) management remains controversial due to variable malignant disease progression rates. While Western studies report 10% to 25% upgrade rates, data from Asian populations, particularly from referral academic centers, are limited. We aimed to identify predictive factors for malignant upgrade in Korean women with AH at academic hospitals. Methods: This retrospective multi-institutional study analyzed 340 patients diagnosed with AH on initial biopsy who underwent subsequent excision at five Korean academic hospitals from 2000 to 2022. Malignant upgrade was defined as ductal carcinoma in situ or invasive cancer on the final pathology. Multivariate logistic regression was used to identify independent predictors of upgrades. Results: Among 340 patients (319 atypical ductal hyperplasia, 20 atypical lobular hyperplasia, and 1 mixed), 128 (37.6%) experienced a malignant upgrade, 98 (76.6%) to ductal carcinoma in situ, and 30 (23.4%) to invasive cancer. In multivariate analysis, multifocal atypia (odds ratio [OR], 25.61; 95% confidence interval [CI], 11.20–58.55; P<0.001) and Breast Imaging-Reporting and Data System 4c-5 lesions (OR, 11.02; 95% CI, 1.43–84.86; P=0.021) were significant predictors. Multifocal atypia showed an 84.4% upgrade rate. Core needle biopsy had higher upgrade rates than vacuum-assisted biopsy (45.2% vs. 20.0%; P<0.001). The upgrade rates decreased from 50% to 25% over the study period (P<0.05). Conclusion The 37.6% upgrade rate in this tertiary referral cohort exceeded that in Western reports, with multifocal atypia emerging as the strongest predictor. These findings support immediate excision for multifocal atypia while allowing individualized management for unifocal lesions with favorable imaging in Korean tertiary care settings.

Objective: Cognitive impairment is common in patients with Parkinson’s disease (PD), and few pharmacological options are available for treating this condition. We evaluated the effects of a digital cognitive training program (SUPERBRAIN), which was previously shown to be effective in populations at risk of Alzheimer’s disease, on cognitive function in individuals with PD. Methods: Twenty-three individuals with PD and mild cognitive impairment (PD-MCI) from four clinics were randomized to the intervention (n=16) or control (n=7) groups. The intervention group completed a 12-week, home-based, tablet-based cognitive training program (25–30 min/day, 7 days/week). Cognitive outcomes were assessed using the Seoul Neuropsychological Screening Battery pre- and post-intervention. Results: The adherence rate was 79.36%. The intervention group showed significant improvements in the Seoul Verbal Learning Test (SVLT) delayed recall and the Controlled Oral Word Association Test, while no changes were observed in the control group. Analysis of covariance confirmed greater SVLT improvement in the intervention group (F statistic=7.15, p=0.015, partial η2=0.28). Conclusion SUPERBRAIN is feasible and can improve cognitive function in individuals with PD-MCI.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.