Purpose: Based on the KEYNOTE-522 study, neoadjuvant pembrolizumab plus chemotherapy has become the standard treatment for early-stage triple-negative breast cancer (TNBC).This study evaluated the real-world efficacy, safety, and predictors of pathologic complete response (pCR) in Korean patients. Methods: We conducted a retrospective cohort study of 174 patients with early-stage TNBC who received the KEYNOTE-522 regimen (neoadjuvant pembrolizumab plus paclitaxel and carboplatin, followed by doxorubicin and cyclophosphamide) at a tertiary cancer center between August 2022 and July 2024. We assessed the primary endpoints, including pCR rate and event-free survival (EFS). We performed univariable and multivariable logistic regression analyses to identify independent predictors of pCR. Results: The median patient age was 50 years (range, 24–74 years). The clinical stages were II and III in 79.3% and 20.1% of patients, respectively, and 10.9% had clinical N3 disease. The overall pCR rate was 62.1%, and the N3 subgroup had a pCR rate of 47.4%. On multivariable analysis, high baseline Ki-67 expression (≥ median, 75%) was significantly associated with pCR (odds ratio, 2.84; 95% confidence interval, 1.45 to 5.66; p = 0.002). At a median followup of 18.4 months, the 12-month EFS rate was 97.4%, with significantly superior outcomes observed in patients who achieved pCR compared with those who did not achieve pCR (100% vs. 93.1%, p = 0.007). The treatment completion rate was 92.0%, and immune-related adverse events occurred in 13.8% of patients. Conclusion In this real-world analysis of one of the largest Asian cohorts of patients with earlystage TNBC treated with neoadjuvant pembrolizumab, the KEYNOTE-522 regimen demonstrated substantial efficacy and manageable toxicity, consistent with the original trial findings.

Background: Left bundle branch block (LBBB) significantly increases the risk of left ventricular systolic dysfunction (LVSD) due to cardiac dyssynchrony. Although artificial intelligence–enabled electrocardiography (AI-ECG) mod‑ els show promise in detecting LVSD, their performance in LBBB patients remains underexplored. We hypothesized that an AI-ECG model clinically validated for detecting LVSD would accurately detect LVSD and predict future clinical outcomes in LBBB patients. Methods: In this retrospective multicenter study, 5,689 expert-validated LBBB ECGs collected from 2,813 patients between 2016 and 2024 were analyzed using a previously developed and validated AI-ECG model. LVSD was defined as an ejection fraction of ≤ 40%. Model performance was assessed using the area under the receiver operating char‑ acteristic curve (AUROC), the area under the precision-recall curve (AUPRC), sensitivity, and specificity. Patients were stratified into high- and low-risk groups based on a threshold that achieved 90% sensitivity. A Kaplan–Meier analysis was used to compare clinical outcomes. Results: Among the 2,813 LBBB patients (mean age, 70.7 years; male sex, 43.7%), hypertension and a history of heart failure were common. The AiTiALVSD model showed strong diagnostic performance for LVSD (AUROC, 0.930 [95% CI, 0.924–0.937]; AUPRC, 0.913 [95% CI, 0.902–0.923]; sensitivity, 0.979; specificity, 0.473). During the mean follow-up of 4.1 years, high-risk patients had significantly higher hazards than low-risk patients for all-cause mortality (adjusted hazard ratio [HR], 1.87; 95% CI, 1.53–2.28), implantable cardioverter defibrillator/cardiac resynchronization therapy implantation (adjusted HR, 15.2; 95% CI, 7.51–30.77), and cardiovascular hospitalization (adjusted HR, 1.11; 95% CI, 0.96–1.28). Conclusions AiTiALVSD effectively detects LVSD and stratifies long-term cardiovascular risk in LBBB patients, support‑ ing its clinical utility for early detection and patient management.

Background/Aims: Endoscopic anti-reflux therapy is a therapeutic option for gastroesophageal reflux disease (GERD), providing durable effects. However, clinical data from Korea remain limited. This study evaluates the clinical outcomes of endoscopic radiofrequency Stretta therapy in Korean patients. Methods: A retrospective analysis was conducted on 71 patients with GERD who underwent Stretta therapy at 2 tertiary hospitals in Korea between November 2015 and July 2021. Clinical outcomes, including patient satisfaction, medication cessation or reduction, and complications, were evaluated. Pre- and post-procedural esophageal manometry and 24-hour pH monitoring test results were also analyzed. Results: Patient satisfaction rates at 1, 6, and 12 months post-procedure were 54.7% (35/64), 70.0% (28/40), and 75.0% (21/28), respectively. Medication cessation or reduction was achieved in 31.2% (20/64) at 1 month, 70.0% (28/40) at 6 months, and 67.9% (19/28) at 12 months. Esophageal manometry (n = 21) showed no significant changes in mean lower esophageal sphincter pressure (18.7 mmHg [2.5-52.9] vs 17.4 mmHg [0.0-43.0], P = 0.702) or mean integrated relaxation pressure (8.2 mmHg [0.0-28.0] vs 10.1 mmHg [0.0-31.0], P = 0.840). The 24-hour pH monitoring (n = 18) demonstrated a nonsignificant decrease in acid exposure time (pH < 4) from 2.3% (0.0-8.4) to 1.6% (0.0-7.3) (P = 0.182). Similarly, the DeMeester score decreased non-significantly from 8.4 (0.8-27.7) to 6.6 (0.8-21.8) (P = 0.352). No procedure-related complications occurred. Conclusion Endoscopic radiofrequency Stretta therapy appears to be a safe treatment option for GERD and may provide favorable patient satisfaction and medication reduction.

Objective: Although most gallbladder polyps are benign, some neoplastic polyps may be malignant or may serve as precursors to malignancy. Distinguishing neoplastic and non-neoplastic polyps using imaging examinations remains a major challenge.This meta-analysis aimed to identify the ultrasound (US) features that are significantly associated with neoplastic polyps. Materials and Methods: The MEDLINE, EMBASE, Cochrane, and KoreaMed databases were searched for articles published up to August 31, 2025. Bivariate random-effects models were used to calculate the meta-analytic pooled diagnostic odds ratios (DORs), sensitivities, and specificities, along with their 95% confidence intervals (CIs), for each US imaging feature in the diagnosis of neoplastic polyps. Results: Thirty studies evaluating 8,953 patients, including 1,216 (13.6%) patients with neoplastic polyps, were included.Among the nine evaluated US imaging features, namely, size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, heterogeneous echogenicity, gallbladder wall thickening (GBWT), absence of hyperechoic spot, and vascularity, eight were significantly associated with neoplastic polyps: size ≥10 mm (DOR: 6.23 [95% CI: 1.86– 20.90]), sessile morphology (DOR: 3.54 [1.93–5.97]), single polyp (DOR: 2.21 [1.76–2.74]), coexisting gallstones (DOR:1.86 [1.29–2.60]), hypoechogenicity (DOR: 3.55 [1.47–7.30]), GBWT (DOR: 9.38 [1.47–32.20]), absence of hyperechoic spots (DOR: 4.23 [2.46–6.83]), and vascularity (DOR: 9.72 [5.81–15.30]). Of these, size ≥10 mm demonstrated the highest pooled sensitivity (0.79 [95% CI: 0.68–0.87]), whereas hypoechogenicity showed the highest pooled specificity (0.93 [95% CI: 0.82–0.98]). Conclusion Eight US imaging features (size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, GBWT, absence of hyperechoic spots, and vascularity) were significantly associated with the presence of neoplastic polyps.These features may facilitate the management of gallbladder polyps.

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.

Alzheimer’s disease (AD) is characterized by progressive cognitive deterioration and significant depression. However, the mechanisms linking depression to AD pathology remain unclear. Here, we investigated whether Notch2 signaling mediates depressionlike behaviors in presenilin-2 (PS2) N141I mutant mice, an early-onset AD model. PS2 wild-type (WT) and mutant (MT) mice aged 12-15 months were subjected to unpredictable chronic mild stress (UCMS) for 4 weeks, followed by sucrose preference, tail-hanging, and forced swimming tests. Behavioral assessments showed that UCMS exacerbated anhedonia and immobility only in PS2 MT mice. Molecular analysis revealed concomitant increases in plasma corticosterone, hippocampal γ-secretase activity, and Notch2 expression, and elevated total and phosphorylated glucocorticoid receptor levels in PS2 MT-UCMS mice. Gene expression profiling of human hippocampal datasets confirmed upregulation of NOTCH2 in Alzheimer’s disease and depression.Pharmacological inhibition of γ-secretase and Notch signaling with DAPT normalizes depressive behavior, reduces corticosterone release, attenuates GR phosphorylation, and inhibits Notch2 signaling in PS2 MT mice. These findings identify Notch2 as a pivotal mediator linking chronic stress to molecular changes associated with depression and AD, and suggest that targeting Notch2 signaling may provide therapeutic benefits for comorbid mood and neurodegenerative disorders.

Objective: We investigated the distribution of AI viruses in fecal samples from wild bird habitats (and nearby poultry-farm areas) surveyed between September and March from 2019 to 2025 and identified associated epidemiological risk factors. Methods: Samples were screened for influenza A (M, H5, H7) genes using real-time reverse transcription polymerase chain reaction (PCR), subjected to virus isolation in embryonated chicken eggs, and subtyped by PCR and sequencing. Host species were identified through DNA barcoding. Relative risks (RRs) with 95% confidence intervals were estimated for province, month, and waterfowl density. Results: Overall prevalence of HPAI and low pathogenic AI (LPAI) virus was 0.10% and 3.21%, respectively. HPAI virus was continuously isolated since 2020–2021, except 2019– 2020, while LPAI prevalence steadily increased (3.01%–4.35%). Twelve hemagglutinin (H1–H12) subtypes were identified in 1,722 isolates, and H3 (16.5%) was the most prevalent, followed by H5 (11.1%) and H7 (5.2%). LPAI H5N3 (55.7%) and H7N7 (75.5%) were the predominant H5 and H7 subtypes, respectively. Detection was higher in western coastal provinces, and higher mallard/spot-billed duck density and sampling in September– December were associated with increased risk. Conclusions and Relevance: Continued surveillance of migratory-bird habitats can provide early warning of HPAIV incursions and support targeted biosecurity measures in high-risk regions and seasons.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group. Methods: This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated. Results: Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures. Conclusion In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.

Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.