Background/Aims: Inaccurate prediction of lymph node metastasis (LNM) may lead to unnecessary surgery following endoscopic resection of T1 colorectal cancer (CRC). We aimed to validate the usefulness of artificial intelligence (AI) models for predicting LNM in patients with T1 CRC. Methods: We analyzed the clinical data, laboratory results, pathological reports, and endoscopic findings of patients who underwent radical surgery for T1 CRC. We developed AI models to predict LNM using four algorithms: regularized logistic regression classifier (RLRC), random forest classifier (RFC), CatBoost classifier (CBC), and the voting classifier (VC). Four histological factors and four endoscopic findings were included to develop AI models. Areas under the receiver operating characteristics curves (AUROCs) were measured to distinguish AI model performance in accordance with the Japanese Society for Cancer of the Colon and Rectum guidelines. Results: Among 1,386 patients with T1 CRC, 173 patients (12.5%) had LNM. The AUROC values of the RLRC, RFC, CBC, and VC models for LNM prediction were significantly higher (0.673, 0.640, 0.679, and 0.677, respectively) than the 0.525 suggested in accordance with the Japanese Society for Cancer of the Colon and Rectum guidelines (vs RLRC, p<0.001; vs RFC, p=0.001; vs CBC, p<0.001; vs VC, p<0.001). The AUROC value was similar between T1 colon versus T1 rectal cancers (0.718 vs 0.615, p=0.700). The AUROC value was also similar between the initial endoscopic resection and initial surgery groups (0.581 vs 0.746, p=0.845). Conclusions AI models trained on the basis of endoscopic findings and pathological features performed well in predicting LNM in patients with T1 CRC regardless of tumor location and initial treatment method.

Background/Aims: We investigated the clinical practice patterns of Korean endoscopists for the endoscopic resection of colorectal polyps. Methods: From September to November 2021, an online survey was conducted regarding the preferred resection methods for colorectal polyps, and responses were compared with the international guidelines. Results: Among 246 respondents, those with <4 years, 4–9 years, and ≥10 years of experiencein colonoscopy practices accounted for 25.6%, 34.1%, and 40.2% of endoscopists, respectively. The most preferred resection methods for non-pedunculated lesions were cold forceps polypectomy for ≤3 mm lesions (81.7%), cold snare polypectomy for 4–5 mm (61.0%) and 6–9 mm (43.5%) lesions, hot endoscopic mucosal resection (EMR) for 10–19 mm lesions (72.0%), precut EMR for 20–25 mm lesions (22.0%), and endoscopic submucosal dissection (ESD) for ≥26 mm lesions (29.3%). Hot EMR was favored for pedunculated lesions with a head size <20 mm and stalk size <10 mm (75.6%) and for those with a head size ≥20 mm or stalk size ≥10 mm (58.5%). For suspected superficial and deep submucosal lesions measuring 10–19 mm and ≥20 mm, ESD (26.0% and 38.6%) and surgery (36.6% and 46.3%) were preferred, respectively. The adherence rate to the guidelines ranged from 11.2% to 96.9%, depending on the size, shape, and histology of the lesions. Conclusions Adherence to the guidelines for endoscopic resection techniques varied depend-ing on the characteristics of colorectal polyps. Thus, an individualized approach is required to increase adherence to the guidelines.

Background/Aims: The aim of this study was to investigate the effect of a surgical treatment algorithm recently proposed by the American Association for the Study of Liver Diseases (AASLD) on survival outcomes in patients with early-stage hepatocellular carcinoma (HCC) and identify effective alternative treatment modalities when liver transplantation (LT) is not available. Methods: We studied the clinical data of 1,442 patients who were diagnosed with early-stage HCC (a single lesion measuring 2–5 cm in size or 2 to 3 lesions measuring ≤3 cm in size) be-tween 2013 and 2018 and classified as Child-Turcotte-Pugh (CTP) A or B. Analyses were separately performed for individuals recommended for resection (single lesion, CTP A and no clinically significant portal hypertension) and those recommended for LT (single lesion with impaired liver function such as CTP B or clinically significant portal hypertension or multiple lesions). Results: Of 791 patients recommended for surgical resection, 85.8% underwent resection. The 5-year survival rate was higher for patients who underwent surgical resection than for those who received other treatments (89.4% vs 72.3%). Among 651 patients recommended for LT, only 3.4% underwent the procedure. The most common alternative treatment modalities were transarterial therapy (39.3%) followed by resection (28.9%) and ablation (27.8%). The overall survival rate associated with transarterial therapy was lower than that for resection and ablation, whereas that of the latter two treatments were comparable. Conclusions The survival outcomes of treatment strategies that most closely aligned with the algorithm proposed by the AASLD were superior to those of alternative treatment approaches.However, LT in patients with early-stage HCC can be challenging. When LT is not feasible, resection and ablation can be considered first-line alternative options.

Background/Aims: Recent studies have shown an increased risk of lower gastrointestinal bleeding in patients who use both nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs). We analyzed the risk of lower gastrointestinal bleeding and compared this risk between NSAID+PPI users and NSAID-only users. Methods: In this retrospective, observational study, data from five hospitals were analyzed using a common data model to determine the risk of lower gastrointestinal bleeding and compare this risk between NSAID+PPI users (target cohort) and NSAID-only users (comparative cohort). Cox proportional hazard models and the Kaplan-Meier estimations were employed after extensive propensity score matching. Results: Among 24,530 individuals in the target cohort and 57,264 in the comparative cohort, 8,728 propensity score-matched pairs were analyzed. The risk of lower gastrointestinal bleeding was significantly higher in NSAID+PPI users than in NSAID-only users (hazard ratio [HR], 2.843;95% confidence interval [CI], 1.998 to 4.044; p<0.001). Similar findings were also noted in elderly patients >65 years (HR, 2.737), males (HR, 2.963), and females (HR, 3.221). However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users (HR, 2.057; 95% CI, 0.714 to 5.924; p=0.172). Conclusions The risk of lower gastrointestinal bleeding was higher in NSAID+PPI users than in NSAID-only users. However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: Although the urea breath test (UBT) is widely used as a representative monitoring test after Helicobacter pylori eradication, false-negative results can occur because of the gray zone related to its cutoff value. This study aimed to compare the diagnostic performances of the rapid urease test (RUT), the RUT with sweeping method, and the UBT, and to investigate the role of the sweeping method in the gray zone of UBT values. Methods: We retrospectively reviewed 216 patients who received standard first-line H. pylori eradication treatments (n=216). All participants underwent to testing using the sweeping method and UBT on the same day. The sensitivity, specificity, and accuracy were analyzed to compare the two methods. Results: The sensitivity (0.537 vs 0.806, p=0.002) and accuracy (0.843 vs 0.870, p=0.026) of the UBT were inferior to those of the sweeping method. A total of 31 individuals tested positive for H. pylori according to the UBT, whereas 54 individuals tested positive according to the sweeping method. In the group for which the gold standard definition indicated H. pylori positivity but UBT results were negative (n=31), all individuals had a UBT value under 2.5‰. In the multivariate logistic regression model, a UBT value of 1.4‰ to 2.5‰ increased the risk of false-negative results by 6.5 times (odds ratio, 6.5; 95% confidence interval, 2.077 to 20.288; p=0.001). Conclusions After H. pylori eradication, false-negative results can occur for individuals undergoing the UBT, primarily for values below the UBT cutoff. The RUT with the sweeping method can potentially help detect H. pylori in the gray zone of the UBT, improving diagnostic accuracy.

Background/Aims: The study investigated the incidence, risk factors, and clinical outcomes of chronic antibiotic-refractory pouchitis (CARP) in Korean patients with ulcerative colitis (UC). Methods: This single-center retrospective study included patients with UC who underwent total proctocolectomy with ileal pouch-anal anastomosis at the Asan Medical Center in Korea between January 1987 and December 2022. The primary outcomes were endoscopic remission and pouch failure. The Cox’s proportional hazard model was used to identify the risk factors for CARP. Results: The clinical data of 232 patients were analyzed. The most common cause of surgery was steroid refractoriness (50.9%), followed by dysplasia/colorectal cancer (26.7%). Among 74 patients (31.9%) with chronic pouchitis (CP), 31 (13.4%) had CARP, and 43 (18.5%) had chronic antibiotic-dependent pouchitis (CADP). The most frequent endoscopic phenotype was focal inflammation of the pouch (CP, 47.3%; CARP, 35.5%; CADP, 55.8%). Patients with CARP were less likely to use concomitant probiotics than patients with CADP (29.0% vs 72.1%, p<0.01). The endoscopic remission rate of CP, CARP, and CADP was 14.9%, 9.7%, and 18.6%, respectively.The pouch failure rate associated with CP, CARP, and CADP was 13.5%, 16.1%, and 11.6%, respectively. Current smoking status (adjusted hazard ratio [aHR], 2.96; 95% confidence interval [CI], 1.27 to 6.90; p=0.01) and previous use of biologics/small molecules (aHR, 2.40; 95% CI, 1.05 to 5.53; p=0.04) were significantly associated with CARP development. Conclusions UC patients who were current smokers and previously used biologics/small molecules had a higher risk of developing CARP. Concomitant use of probiotics was less likely to be associated with CARP development.

Probiotics exert various effects on the body and provide different health benefits. Previous reports have demonstrated that the P8 protein (P8), isolated from Lactobacillus rhamnosus, has anticancer properties. However, its efficacy in stem cells and normal cells has not been reported. In this study, the effect of P8 on cell proliferation and wound healing was evaluated, investigating its underlying mechanism. Based on scratch assay results, we demonstrated that P8 treatment significantly increases wound healing by activating the cell cycle and promoting stem cell stemness.Cellular mechanisms were further investigated by culturing stem cells in a medium containing Lactobacillus-derived P8 protein, revealing its promotion of cell proliferation and migration. Also, it is found that P8 enhances the expression of stemness markers, such as OCT4 and SOX2, along with activation of the mitogen-activated protein kinase (MAPK) signaling and Hippo pathways. These results indicate that P8 can promote cell growth by increasing stem cell proliferation, migration, and stemness in a manner associated with MAPK and Hippo signaling, which could contribute to the increased wound healing after P8 treatment. Furthermore, P8 could promote wound healing in keratinocytes by activating the MAPK signaling pathways. These results suggest that P8 might be a promising candidate to enhance stem cell culture efficiency by activating cell proliferation, and enhance therapeutic effects in skin diseases.

Purpose: This study systematically reviewed and analyzed the effects of non-pharmacological interventions on internalized stigma among people with severe mental illness. Methods: A systematic review and meta-analysis were conducted following the Cochrane Intervention Research Systematic Review Manual and Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. This study targeted people with severe mental illness as the population, interventions aimed at reducing internalized stigma, comparisons with control groups, and internalized stigma as the outcome. A literature search was performed across multiple databases, including PubMed, EMBASE, the Cochrane Library, CINAHL, PsycArticles, RISS, KMbase, and KoreaMed. The risk of bias was evaluated using the Cochrane Risk of Bias 2.0 tool. Effect sizes were computed using Hedges’s g, and subgroup analyses were conducted with Comprehensive Meta-Analysis software version 4.0. Results: Of 2,388 papers, 15 were included in the meta-analysis. The overall effect size (Hedges’s g) of the intervention was –0.60 (95% confidence interval, –1.01 to –0.19), indicating a statistically significant reduction in internalized stigma (Z=–2.88, p=.004). Subgroup analyses revealed that the intervention type (p=.008) and session length (p=.011) were significant moderators influencing the effectiveness of the interventions. Conclusion Tailoring interventions by considering variables such as the intervention type and session length could enhance the effectiveness of non-pharmacological interventions for reducing internalized stigma among people with severe mental illness (PROSPERO: CRD42023418561).

Purpose: This study aimed to evaluate the effects of an intervention combining warm therapy (via a thermoelectric-element tourniquet) and a distraction-based approach (via an augmented reality-based app known as TWINKLE) on pain, stress, and satisfaction during intravenous catheterization in adults. Methods: A randomized controlled trial was conducted in South Korea with 93 healthy adults who were randomly assigned to one of three groups: the experimental group (TWINKLE app with warm therapy), the comparison group (warm therapy only), and the control group (no treatment). Participants’ pain, stress, and satisfaction, as well as practitioner satisfaction, were measured after the intervention. Results: Pain scores differed significantly among the three groups (F = 5.68, p = .005), with the experimental group showing significantly lower scores than the control group (p = .003). Stress levels were also significantly lower in the experimental group than in the other groups (F = 9.42, p < .001). Participant satisfaction was highest in the experimental group (F = 17.65, p < .001), while nurse satisfaction was significantly higher in the comparison group than in the experimental and control groups (F = 67.91, p < .001), suggesting that the additional distraction intervention may have increased nurses’ workload. Conclusion Combining digital distraction with warm therapy using a thermoelectric-element tourniquet effectively reduces pain and stress while improving patient satisfaction during intravenous catheterization. Further research is needed to optimize this approach, with a particular focus on targeting digital distraction interventions to patients with higher levels of procedural anxiety and finding ways to minimize practitioner workload.