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.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.

Objective: Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis in children, with an unknown cause and prolonged disease course. Biologic disease-modifying anti-rheumatic drugs (bDMARDs) have improved outcomes in severe or refractory cases, but challenges remain due to disease heterogeneity and long-term management needs. Understanding treatment patterns of novel therapies is essential for optimizing care. This study aimed to investigate bDMARD treatment patterns in JIA patients using a real-world database. Methods: A retrospective analysis was conducted using Health Insurance Review and Assessment (HIRA) national claims data from 2007 to 2019. JIA patients were classified into bDMARDs and non-bDMARDs groups, with treatment patterns compared. Results: Among 1,728 JIA patients, 31.3% (n=541) received bDMARDs, with 15.5% (n=84) discontinuing treatment. The median time from diagnosis to first bDMARD was 36.7 (9.7~58.1) months, with a median treatment duration of 28.1 (11.5~54.4) months and follow-up of 24.3 (7.7~43.7) months post-discontinuation. In the non-bDMARDs group (68.7%, n=1,187), 68.7% (n=815) used conventional synthetic DMARDs (csDMARDs), with a 46.6% (n=380) discontinuation rate. Methotrexate, sulfasalazine, and hydroxychloroquine were the most prescribed csDMARDs. Etanercept (69.7%) was the most common first bDMARD, followed by adalimumab (19.0%) and tocilizumab (7.6%), with 14.8% switching to a second biologic. Discontinuation rates of csDMARDs were higher in the non-bDMARDs group (p<0.001). Conclusion This is the first comprehensive study profiling the treatment patterns of Korean patients with JIA using populationbased claims data. The findings enhance understanding of real-world treatment trends, aiding clinical decision-making.

Objective: To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines. Materials and Methods: This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022. Results: A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018. Conclusion The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.

Background: Despite advancements in laboratory animal facility management, pinworm infections remain a persistent issue in immunodeficient mouse colonies. Rapid diagnosis and treatment are crucial to mitigating potential scientific and economic consequences. Effective control requires both the administration of anthelmintic agents and rigorous environmental decontamination. However, the safety and efficacy of these treatments in genetically modified mouse models remains uncertain.Case presentation Aspiculuris tetraptera infestation was identified in multiple immunodeficient mouse models housed in a laboratory facility. Diagnosis was confirmed through fecal flotation for egg detection and necropsy for adult worm examination in the large intestines. Mice received three subcutaneous ivermectin injections at two-week intervals, coupled with environmental decontamination using ivermectin spray for four consecutive weeks. Following treatment, all colonies tested negative for A. tetraptera without any mortality. Conclusions A combination of subcutaneous ivermectin injection and environmental spray application effectively eradicated A. tetraptera infestation in immunodeficient mouse colonies. The treatment protocol led to the complete elimination of eggs and adult worms, offering a practical strategy for managing pinworm infections in genetically modified mouse models. Limitations include the small sample size, and the lack of a comprehensive evaluation of physiological and metabolic safety in immunodeficient mice. Further validation will be required to confirm the broader applicability of this approach.

The Wikstroemia genus is highly regarded in traditional Asian medicine for its diverse therapeutic applications, including the treatment of inflammatory and infectious conditions. Among its members,Wikstroemia trichotoma (Thunb.) Makino remains a promising medicinal resource which is yet to be chemicallycharacterized. To ensure the chemical consistency of W. trichotoma, we developed and validated the first HPLC method for the simultaneous quantification of three major marker compounds: chlorogenic acid (1), miconioside B (2), and matteucinol 7-O-apiofuranosyl(1→6)-glucopyranoside (3). Chromatographic separation was achieved on a C18 column using a gradient elution system of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Detection was optimized using a photodiode array (PDA) detector at 280 and 325 nm, based on the absorption maxima of the markers. The method was validated in accordance with the International Council for Harmonisation (ICH) and the Ministry of Food and Drug Safety (MFDS) guidelines. The results demonstrated high linearity (r2 > 0.999), with limits of detection and quantitation ranging from 4.28–6.42 and 12.97–19.47 μg/ mL, respectively. Intra- and inter-day precision (% RSD ≤ 1.83%) and accuracy (recoveries of 92.5–101.7%) were within acceptable limits. Quantitative analysis revealed the contents of 1, 2, and 3 in the W. trichotoma extract to be 19.9, 139.8, and 264.9 mg/g, respectively. This study provides a reliable analytical framework for the standardization, quality control, and future pharmacological evaluation of W. trichotoma.

BACKGROUND/OBJECTIVES: Dietary supplement use is common among breast cancer survivors, but studies on Asian populations remain limited. This study investigated dietary supplement use among Korean breast cancer survivors, distinguishing between vitamin/ mineral (VM) and non-vitaminon-mineral (NVNM) supplements. SUBJECTS/METHODS: This cross-sectional study included 1,136 stage I–III breast cancer survivors from 12 Korean hospitals, who survived more than 6 mon post-surgery. The participants completed a questionnaire on post-diagnostic dietary supplement use. Stepwise logistic regression was applied, calculating odds ratios (ORs) and 95% confidence intervals (CIs) to identify the demographic and clinical factors associated with VM and NVNM use. RESULTS: Seventy percent of survivors reported supplement use, with 25% using a single product. The most common VM supplements were multivitamins/minerals, vitamin D, and vitamin C, while the most common NVNM supplements included omega-3 fatty acids, probiotics, and ginseng. Survivors with higher education and greater physical activity were more likely to use VM supplements (ORs [95% CIs], 2.74 [1.76–4.25] for college graduates or above vs. middle school or below; 1.38 [1.02–1.88] for the most active group vs. the least active group). NVNM use was associated with higher education, greater physical activity levels, and a history of smoking (ORs [95% CIs], 2.29 [1.46–3.58] for college graduates or above vs. middle school or below; 1.52 [1.13–2.06] for the most active group vs. the least active group; 2.00 [1.23–3.25] for ever smokers vs. never smokers). Survivors who had undergone chemotherapy were also more likely to use NVNM supplements than those who had not (OR [95% CI], 1.37 [1.02–1.84]). CONCLUSION Seventy percent of Korean breast cancer survivors used dietary supplements in this study. VM use was associated with higher education and physical activity, while higher NVNM use was associated with higher education, greater physical activity, a history of smoking, and chemotherapy.

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.

Background/Aims: Early detection and removal of colon polyps are critical for preventing colorectal cancer. Computer-aided detection (CADe) systems have been introduced to increase the polyp detection rate (PDR) during colonoscopy, potentially enhancing its effectiveness. This study aimed to evaluate the efficacy of a CADe system in colorectal neoplasm detection. Methods: This prospective, randomized controlled trial was conducted at two tertiary centers (May 2023 to April 2025). Patients were randomly assigned to CADe or conventional colonoscopy and underwent screening, surveillance, or diagnostic colonoscopy. The primary endpoint was the adenoma detection rate (ADR), while the secondary endpoints were the PDR, relative risk (RR) of polyp detection, adenomas per colonoscopy (APC), and factors influencing adenoma detection. Results: Of 1,004 enrolled patients, 998 were randomly allocated into CADe and conventional colonoscopy groups (497 CADe system and 501 conventional colonoscopy). The CADe group had greater polyp counts (2.2 per colonoscopy vs 1.4 per colonoscopy; p<0.001) and APC values (1.2 vs 0.8; p<0.001). The CADe group showed significantly higher PDRs (72.2% vs 54.5%;p<0.001; RR, 2.173; 95% confidence interval [CI], 1.669 to 2.828) and ADRs (52.3% vs 36.1%;p<0.001; RR, 1.940; 95% CI, 1.505 to 2.499). CADe also significantly increased the detection rate of hyperplastic polyps (p=0.007; RR, 1.474; 95% CI, 1.113 to 1.952) and increased the detection rates across all sizes and locations. In multivariable analysis, CADe use was the strongest independent predictor of adenoma detection (odds ratio, 1.914; 95% CI, 1.467 to 2.496), outweighing male sex, older age, diagnostic indication, and withdrawal time. Conclusions Real-time CADe-assisted colonoscopy significantly increased PDR and ADR and proved to be a strong independent predictor of adenoma detection (cris.nih.go.kr, KCT0009664).