Background: This study aims to compare the effects of short- and intermediate-acting erythropoiesis-stimulating agents (ESAs) on hemoglobin (Hb) variability in patients undergoing maintenance hemodialysis. Methods: This retrospective cohort study included 119 patients who were classified into two groups based on ESA type: short-acting ESA (epoetin alfa/beta [EPO], n=48) and intermediate-acting ESA (darbepoetin alfa [DPO], n=71). Hb levels were measured 11 times at 4-week intervals from ESA therapy initiation to 40 weeks of follow-up. This study used established metrics from previous research, including standard deviation (SD), coefficient of variation (CV), and residual SD, to quantify Hb variability. Results: Over the 40-week study period with 4-week measurement intervals, mean Hb levels were comparable between the two ESA groups. In the EPO and DPO groups, SD was 0.67±0.19 g/dL and 0.69±0.22 g/dL, respectively (p=0.516), CV was 0.06±0.02 and 0.07±0.02, respectively (p=0.480), and residual SD was 0.73±0.21 g/dL and 0.76±0.26 g/dL, respectively (p=0.463). No significant differences in Hb variability were observed between the groups over 40 weeks using SD, CV, and residual SD. Conclusion This retrospective cohort study showed comparable mean Hb levels and Hb variability indices between groups. With respect to Hb variability, the findings reveal no clear basis for prioritizing either short-acting or intermediate-acting ESA.

Background: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced malignant melanoma. This study examined the real-world efficacy of dacarbazine (dimethyl triazeno imidazole carboxamide, DTIC) in patients who had previously received pembrolizumab, based on the hypothesis that prior ICI treatment enhances the therapeutic response to subsequent chemotherapy. Methods: This retrospective study included 71 patients with histologically confirmed malignant melanoma treated at Kyungpook National University Chilgok Hospital (Daegu, Korea) between 2011 and 2023. The patients received DTIC for unresectable stage IIIC, IIID, or IV melanoma (American Joint Committee on Cancer, 8th edition). Results: Among the 71 patients, the median patient age was 64 years (range, 25–89 years). When categorized by melanoma subtype, 18 patients (25.4%) had acral melanoma, 40 (56.3%) had cutaneous melanoma, and 13 (18.3%) had mucosal melanoma. Sixteen of the DTIC-treated patients had not received pembrolizumab previously (DTIC-only group), while 55 had (pem-DTIC group). The median progression-free survival was 2.3 months in the DTIC-only group and 3.9 months in the pem-DTIC group (hazard ratio [HR], 0.246; 95% confidence interval [CI], 0.106–0.576; p=0.001). The median overall survival was 6.8 months in the DTIC-only group and 19.0 months in the pem-DTIC group (HR, 0.198; 95% CI, 0.068–0.574; p=0.003). The duration of response (DoR) was 4.64 months in the DTIC group and 8.11 months in the pem-DTIC group. Conclusion This study demonstrated that the DoR to DTIC was prolonged following ICI therapy (4.64 months vs. 8.11 months). This indicates that prior ICI treatment may enhance tumor sensitivity to chemotherapy, making DTIC a viable option for treating refractory, relapsed, or progressive melanoma.

Objectives: Large language models (LLMs) demonstrate remarkable potential in healthcare communication. However, whether they can process complex, high-volume medical information, such as stroke-related content, remains insufficiently validated. This study aimed to evaluate the natural language processing capabilities of LLMs in handling such content and to develop an evaluation instrument. Methods: A survey compared educational materials generated by two LLMs (ChatGPT 4.0 and Claude 3) with neurologist-authored content on stroke. The materials were based on two clinical scenarios representing distinct stroke etiologies: cardioembolism and large-artery atherosclerosis. They were evaluated in terms of accuracy, legality, ethics, comprehensiveness, and information delivery. Scores for comprehensiveness and information delivery were compared according to participants’ agreement with the use of LLMs in healthcare. Results: ChatGPT received the highest scores across all domains, except for legality in Scenario 2. In Scenario 1, the ranking for accuracy and summarization of clinical information was, from highest to lowest, ChatGPT, Claude, and the neurologist (η2 = 0.140, p < 0.001; η2 = 0.175, p < 0.001). The same hierarchy was observed in Scenario 2 for accuracy (η2 = 0.077, p < 0.001) and summarization (η2 = 0.194, p < 0.001). Participants who agreed with the use of LLMs in healthcare assigned higher scores for the comprehensiveness (Scenario 1, p = 0.005; Scenario 2, p = 0.007) and information delivery (Scenario 1, p = 0.003; Scenario 2, p = 0.026) of ChatGPT-generated materials than participants who did not agree. Conclusions LLMs demonstrated adequate capability to convey complex content, such as stroke-related information, in an accessible and understandable manner for non-experts.

Background: Research on the relationship between the progression of interstitial lung abnormalities (ILA) and serum biomarkers, including white blood cell differential counts and Krebs von den Lungen-6 (KL-6), is limited. This study aimed to examine the clinical characteristics of patients with ILA and evaluate the association between disease progression and serum biomarkers. Methods: This retrospective cohort study analyzed data from 159 patients (63 with ILA and 74 with interstitial lung diseases) between October 2021 and September 2022. Data collected included clinical characteristics, pulmonary function tests, chest computed tomography (CT), complete blood cell counts, and KL-6 levels. In 52 of these patients who had previously undergone chest CT, the utility of serum biomarkers in reflecting radiologic progression was assessed using receiver operating characteristic curve analysis. Results: Patients with ILA exhibited clinical characteristics similar to those with idiopathic pulmonary fibrosis. Serum KL-6 levels did not correlate with forced vital capacity or diffusing capacity of the lung for carbon monoxide in patients with ILA. Among the 52 patients with ILA, 13 demonstrated radiologic progression. Serum KL-6 displayed moderate predictive performance, with area under the curves ranging from 0.57 to 0.89 (p=0.014) for radiologic progression. Levels of KL-6 greater than 400 U/mL were more frequently observed in patients with radiologic progression (61.5% vs. 20.5%, p=0.006). In multivariate analysis, age and KL-6 were independently associated with radiologic progression in patients with ILA. Conclusion Serum KL-6 levels may serve as a potential indicator of ILA progression in asymptomatic patients. Those with KL-6 levels exceeding 400 U/mL should be closely monitored for radiologic progression.

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.

Coronary artery bypass grafting (CABG) remains a key revascularization strategy for ischemic heart disease; however, nationwide trends in the Republic of Korea have not been thoroughly investigated. Using data from the Korean National Health Insurance Service, we analyzed adult patients who underwent isolated CABG between 2005 and 2022. We evaluated surgical volume, patient demographics, procedural strategies (off-pump vs. onpump), and outcomes. International comparisons were conducted using national cardiac surgery registry data. A total of 51,923 CABG cases were identified. Annual surgical volume declined until 2013 but gradually increased thereafter, reaching 3,717 cases in 2022. Despite this recovery, Korea’s per capita CABG rate remains among the lowest worldwide.In contrast, more than 60% of procedures were performed off-pump—the highest rate worldwide. Over time, the average patient age and prevalence of diabetes increased, whereas in-hospital mortality showed a modest decline. Compared with other countries, the Republic of Korea demonstrated a uniquely low procedural volume and a strong preference for off-pump CABG. This nationwide analysis highlights Korea’s distinctive CABG practice patterns and provides valuable insights for optimizing future clinical and policy decisions in cardiac surgical care.

Background: Although patients with malignant melanoma in situ (MIS) have a high survival rate, a risk of recurrence or upstaging remains. Thus, a comprehensive understanding of its prognosis is essential for optimal patient management. Objective: To investigate the clinical characteristics and survival outcomes of Korean patients with MIS. Methods: We retrospectively analyzed the medical records and photographs of patients with MIS treated at a single tertiary center between 2008 and 2021. Clinical features, including diagnosis, treatment, recurrence, and mortality, were examined. Results: A total of 156 patients with MIS were included, with a mean age of 59.3 years. The most common subtype was acral lentiginous melanoma (80.8%). Delayed diagnosis was associated with subungual MIS (SUMis; p ＜0.05). Among the subtypes other than SUMis, 77.3% met three or more of the ABCD criteria for melanoma.Hutchinson’s sign was observed in 67.3% of cases of SUMis. Ulceration was present in only two cases (1.3%).Recurrence occurred in nine patients (5.8%), with four (2.6%) experiencing relapse after 5 years. Upstaging was observed in two patients (1.3%) due to intralymphatic or regional nodal metastasis occurring at 19 and 10 months post-treatment. The 5-year and 10-year melanoma-specific/overall survival rates were 100.0/96.9% and 100.0/89.0%, respectively. Conclusion Although the survival rates of patients with MIS are high, long-term and close follow-up after treatment is essential because of the possibility of late recurrence and rare instances of intralymphatic or regional nodal metastasis. Additionally, the presence of clinical ulceration is highly suggestive of invasive melanoma.

Purpose: To propose improvements for promoting eyeball donation and managing donated corneas, this study analyzed the current system in Korea and reviewed relevant Korean laws, international standards, and foreign practices. Methods: To understand the current situation in Korea, annual reports published by the Korean Network for Organ Sharing and existing Korean laws were examined. For the international context, references were made to the National Organ Transplant Act, 21 CFR Part 1271 (Code of Federal Regulations Title 21 Part 1271), Current Good Tissue Practice guidelines of the Food and Drug Administration, and the Medical Standards of the Eye Bank Association of America in the United States. Opinions on promoting eyeball donation, improving the monitoring system for donated corneas and revising laws related to cornea management were gathered. The perspectives of 31 experts affiliated with the Korea Cornea Society were collected through a survey. Results: Currently, there are no laws or regulations that can be appropriately applied to the cornea which has properties of both organs and tissue. Additionally, there is no law regulating imported corneas. Therefore, there is a need to legislate or revise the current law; all experts who conducted the survey agreed on this. Furthermore, the current system faces limitations in the efficient procurement, stable supply, and management of donor corneas, as well as in donation promotion. To address these issues, the establishment of independent legislation for managing donated corneas and a National Central Eye Bank was proposed. This central body would oversee continuous personnel training, education, and monitoring, along with ensuring stable procurement, processing, and supply of corneas within a structured management system. Sixty-eight percent of the surveyed experts agreed with this proposal. Conclusions To establish a safe and efficient Korean corneal supply and demand system, it is imperative to enact cornea-specific laws, including the establishment of a National Central Eye Bank.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.