Background: This study investigated the prognostic value of bilaterality and multifocality in papillary thyroid carcinoma (PTC) recurrence, aiming to inform optimal surgical strategies. Methods: In this retrospective cohort, 1,966 patients who underwent total thyroidectomy for PTC (2011–2014) were categorized into four groups according to tumor multifocality and bilaterality confirmed by postoperative histopathology: group 1, unilateral solitary; group 2, unilateral multifocal; group 3, bilateral solitary; group 4, bilateral multifocal. Clinicopathologic features and clinical outcomes were compared across these groups. Results: Group 4 exhibited the highest prevalence of BRAFV600E positivity, nodal metastases, and recurrence. Both bilaterality and multifocality were associated with more aggressive clinicopathologic characteristics. Recurrence risk increased with the number of tumor foci, with the odds ratio (OR) significantly elevated for more than five foci. Satellite pattern was strongly linked to recurrence (OR, 19.49; P<0.001). While tumor multifocality (≥5 foci) and bilaterality were associated with recurrence in univariate analyses, these associations were not independent after adjustment. Kaplan-Meier analysis demonstrated the lowest recurrence-free survival (RFS) in group 4. Patients with bilateral disease had significantly lower RFS than those with unilateral disease (P=0.003), whereas multifocality did not significantly affect RFS compared to solitary disease (P=0.095). Conclusion Tumor bilaterality, multifocality (≥5 foci), and satellite pattern were associated with aggressive features and higher recurrence risk. Although not independent predictors, these factors may serve as useful surrogate markers of aggressive disease biology and help guide personalized surgical strategies in patients with PTC.

Background: Despite the rising incidence of end-stage renal disease (ESRD) among individuals with type 2 diabetes mellitus (T2DM) in Korea, no predictive model or nomogram has been developed using a nationwide cohort. In this study, we developed a nomogram to predict the long-term risk of ESRD in patients with T2DM using a large-scale, population-based Korean database. Methods: Using the Korean National Health Insurance Database, patients with T2DM who underwent health examinations between 2015 and 2016 were assigned as development (n=1,744,277) and validation (n=747,407) cohorts. New ESRD cases were identified using codes for renal replacement therapy. A Cox proportional hazards regression model was used to derive a risk-scoring system, and 13 variables were selected. A risk score nomogram was then created to estimate the risk of ESRD. Results: In the development cohort, 8,631 patients with T2DM developed ESRD during a follow-up period of 4.8±0.9 years. After multivariable adjustment, significant predictors of ESRD included male sex, current smoking, physical inactivity, low income, low body mass index, hypertension, low-density lipoprotein cholesterol ≥160 mg/dL, chronic kidney disease, insulin use, and longer duration of T2DM. A final nomogram incorporating 13 variables was developed to estimate the individual probability of ESRD. The concordance index for ESRD prediction in the validation cohort was 0.906 (95% confidence interval, 0.9 to 0.912). Conclusion This 13-variable nomogram provides a simple tool for identifying patients with T2DM at high risk of ESRD and may aid in early intervention.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic had direct effects on population health through infection and morbidity, as well as indirect effects on population mental health. We estimated the network structure of post-traumatic stress symptoms (PTSS) and depressive symptoms throughout the pandemic in Korea and aimed to identify the most central and bridging symptoms. METHODS: Participants aged 30–64 years completed mental health surveys across 3 phases of the COVID-19 pandemic: March 2020 (n=1,925), February–March 2021 (n=1,754), and December 2021–January 2022 (n=1,595). Using PTSS and depressive symptom data, we conducted network analyses, and the primary measures of symptom importance (centrality) were expected influence and bridge expected influence. RESULTS: In the comorbidity network, although the most central symptoms fluctuated over the course of the pandemic, sleep problems were consistently identified as the most influential bridge symptoms throughout. The symptom network structure differed between the subacute and chronic phases of the pandemic. CONCLUSIONS We found evidence of changes in the network structure of PTSS and depressive symptoms, even as sleep problems retained a consistent role as a bridging symptom. Although overall network structures varied across phases of the pandemic, the bridging role of sleep-related symptoms remained consistently strong, suggesting that sleep problems may represent a general and enduring mechanism underlying PTSS–depression comorbidity. During future pandemics, prompt screening for sleep problems may help prevent the development of comorbidity between PTSS and depressive symptoms.

Background and Objectives: Circulating microRNAs (miRNAs) have been proposed as potential biomarkers in atrial fibrillation (AF) and heart failure (HF), but their role in patients with AF and heart failure with preserved ejection fraction (HFpEF) remains uncertain. Methods: We measured serum levels of 4 candidate miRNAs (miR-21, miR-146a, miR-146b, and miR-328) using quantitative polymerase chain reaction in 45 patients with persistent AF and HFpEF and five non-AF arrhythmia controls (Healthy). Expression levels were normalized to miR-16 and expressed as fold change (2−ΔCt ). Baseline (V1) and 3–6 months follow-up (V2) samples were analyzed, and comparisons were performed using non-parametric tests. Results: At baseline, none of the 4 miRNAs differed significantly between AF patients and Healthy controls; miR-21, 1.24 ± 0.55 vs. 1.15 ± 0.32 (P = 0.57); miR-146a, 0.66 ± 0.35 vs. 0.65 ± 0.06 (P = 0.71); miR-146b, 0.12 ± 0.07 vs. 0.11 ± 0.01 (P = 0.90); and miR-328, 0.08 ± 0.05 vs. 0.07 ± 0.03 (P = 0.95), all P > 0.5. Baseline comparisons were analyzed using relative expression values (2−ΔCt , normalized to miR-16), while longitudinal changes between V1 and V2 were assessed using fold change (2−ΔΔCt ). No significant longitudinal changes were observed across treatment groups. Conclusions In patients with persistent AF and HFpEF/HF with mildly reduced ejection fraction, circulating miR-21, miR-146a, miR-146b, and miR-328 showed no significant differences compared with the non-AF arrhythmia control group and did not change after 6 months of renin-angiotensin-aldosterone system-targeted therapy. These pilot data suggest that the short-term utility of biomarkers is limited and warrants validation in larger, randomized cohorts.

In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Purpose: Langer's axillary arch (LAA) is a common muscular variant that may affect the assessment of axillary lymph nodes in breast cancer. We investigated whether the presence of the LAA had a meaningful clinical impact in a large cohort of Korean patients with breast cancer. Methods: The medical records and imaging of 2,904 patients (2,953 cases) who underwent axillary surgery for breast cancer were reviewed. The presence of LAA was determined using chest computed tomography scans. The number of retrieved lymph nodes, the accuracy of axillary ultrasonography, and survival outcomes were compared between the LAA and nonLAA groups. Results: The LAA muscle was identified in 301 patients (10.2%). Preoperative ultrasound evaluation showed a lower specificity in the LAA group (77.9% vs. 83.6%, p = 0.031).Additionally, invasive disease-free survival (iDFS) was significantly worse in the ‘LAA-positive patients’ after adjusting for stage, histologic grade, and treatment (adjusted hazard ratio, 2.00; 95% confidence interval, 1.00–4.01; p = 0.048), with regional axillary recurrence being notably more frequent in patients with the LAA muscle (p = 0.005). Conclusion The presence of the LAA muscle was associated with reduced specificity on preoperative ultrasound. Patients with LAA muscle-associated tumors had worse iDFS, with regional axillary recurrence occurring more frequently. Recognition of the LAA muscle during axillary staging and surgery may improve nodal assessment accuracy and outcomes, especially in the era of axillary surgery de-escalation.

Purpose: This study aimed to develop a digital multimedia-based educational intervention for hematopoietic stem cell (HSC) donors and to evaluate its effects on anxiety, knowledge, attitudes toward hematopoietic stem cell donation, and educational satisfaction. Methods: This quasi-experimental study employed a nonequivalent control group non-synchronized pretest-posttest design. Participants were 60 HSC donors admitted to a general hospital in Seoul, Republic of Korea, between April and December 2024. The participants were assigned to an experimental group (n=30) and a control group (n=30). The experimental group received a digital multimediabased educational intervention in addition to the usual education using a standardized handout, whereas the control group received the usual education only. The intervention was provided in three sessions: on the day of admission (20 minutes), on the day of stem cell collection (10 minutes), and on the day of discharge (10 minutes). Data were collected at admission and discharge using structured questionnaires. Anxiety was analyzed using generalized estimating equations (GEE), knowledge and attitudes using mixed ANOVA, and educational satisfaction using an independent t-test. Results: The experimental group showed significantly lower anxiety (p=.048) and higher knowledge levels (p=.005) than the control group. No significant differences were found between the groups in attitudes toward donation or educational satisfaction. Conclusion The digital multimedia-based educational intervention was effective in reducing anxiety and improving knowledge among HSC donors. This intervention may enhance donors’ understanding of the donation process and support a more positive donation experience. Further multicenter studies with larger samples and longitudinal follow-up measurements are needed to verify the long-term effects and generalizability of the intervention.

Purpose: Declines in masticatory function have been reported to be closely associated with cognitive impairment and reduced brain activity in older adults. This study aimed to investigate the effects of intraoral vibratory stimulation on masticatory function, cognitive performance, and brain activity in elderly individuals and to evaluate its potential efficacy. Materials and Methods: Participants were divided into a vibration-stimulation group (n=9) and a non-vibration control group (n=7). Baseline assessments were conducted at the first visit. Participants then received either vibratory stimulation or a wash-out (control) condition for two weeks, followed by the same assessments at the final visit. Evaluation measures were dental assessments (maximum bite force, masticatory performance, and salivary flow rate), cognitive tests (CANTAB, paper-based and computerized tests), quantitative electroencephalography (qEEG), and functional magnetic resonance imaging (fMRI) during a short-term memory task. Results: No significant long-term effects or statistically meaningful differences were observed between the two groups in cognitive performance or brain activity. Similarly, no pre- to post-intervention differences were found between groups in dental measures related to masticatory function (maximum bite force, masticatory performance, and salivary flow rate). Due to the limited sample size, this study functioned as a pilot study focusing on descriptive rather than inferential statistical analysis. Conclusion Intraoral vibratory stimulation did not demonstrate immediate or clear effects on cognitive function or brain activity in older adults, suggesting the need for optimization of stimulation parameters such as location and intensity. Future studies with larger sample sizes and improved stimulation methods replicating masticatory function are warranted to further explore the potential cognitive benefits.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

Olanzapine is a second-generation antipsychotic drug associated with the development of type 2 diabetes. However, the development and remission of diabetes with glutamic acid decarboxylase (GAD) antibody (Ab) positivity related to olanzapine treatment have not been reported. Here, we present the case of a 33-year-old man taking olanzapine who was diagnosed with diabetes with GAD Ab positivity complicated by diabetic ketoacidosis (DKA). After discontinuation of the drug and tight glycemic control, his diabetes remitted, and the GAD Ab became negative spontaneously after 18 months. The classification of diabetes is challenging because of overlapping autoimmune and metabolic features. Olanzapine may have contributed to pancreatic β-cell apoptosis, which could potentially trigger autoimmunity and the development of type 1 diabetes-like features (DKA as the initial presentation, a low C-peptide level, and GAD Ab positivity). The rapid amelioration of hyperglycemia and weight reduction may be responsible for the remission of diabetes after the discontinuation of olanzapine.