Purpose: Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood. Materials and Methods: We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared. Results: A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes. Conclusions GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.

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.

Purpose: Radical cystectomy (RC) is associated with substantial postoperative morbidity, and unplanned readmission remains common despite advances in perioperative management. However, the association between postoperative readmission due to complications and oncologic outcomes after RC for bladder cancer has not been clearly defined. We evaluated the impact of postoperative readmission on overall survival (OS) and cancer-specific survival (CSS) after RC for bladder cancer. Materials and Methods: We retrospectively analyzed 3,972 patients who underwent RC for bladder cancer in a multicenter cohort. Postoperative readmission was defined as unplanned hospitalization within 90 days postsurgery due to surgery-related complications. Survival outcomes were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify independent predictors of OS and CSS. Results: Among the study population, 916 patients (23.1%) experienced postoperative readmission. Baseline and perioperative characteristics were generally comparable between patients with and without readmission. Kaplan-Meier analyses demonstrated significantly worse OS and CSS among patients who experienced postoperative readmission (both log-rank p<0.001). In multivariable analyses adjusting for clinicopathological factors, postoperative readmission remained independently associated with worse OS (hazard ratio [HR], 1.654; 95% confidence interval [CI], 1.464–1.868; p<0.001) and CSS (HR, 1.761; 95% CI, 1.509–2.055; p<0.001). Conclusion Postoperative readmission within 90 days after RC was independently associated with inferior long-term oncologic outcomes. These findings suggest the importance of strategies aimed at preventing postoperative complications and subsequent readmission.

Objective: To characterize toxin gene profiles and antimicrobial resistance among Clostridium perfringens isolated from diarrheic piglets in Korea. Methods: Fecal samples (n = 1,627) were collected from 286 farms in 2023–2024. Clostridium perfringens isolates (n = 410) were recovered under anaerobic conditions. Toxin genes (cpa, cpb, cpb2, cpe, etx, and iap) were detected by multiplex real-time polymerase chain reaction.Susceptibility to 18 antimicrobials was assessed by disc diffusion. Results: Type A strains (cpa alone [24.6%] or cpa+cpb2 [46.8%]) predominated; cpb2 and cpe were detected in 73.4% and 19.0% of isolates, respectively. Resistance was highest to bacitracin (94.9%), amoxicillin/clavulanic acid (79.8%), and florfenicol (81.5%). Conclusions and Relevance: In 2023–2024, type A isolates carrying cpb2 were the predominant toxinotype among Clostridium perfringens recovered from diarrheic piglets in Korea. The high prevalence of resistance to several commonly used agents supports strengthened antimicrobial stewardship and evaluation of alternative control strategies.

Objectives: 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. 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 5460 ESD cases from 5250 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.

Background: Hypercalcemia of malignancy (HCM), a major metabolic complication of cancer, is often managed with bisphosphonates (BP) and, increasingly, with denosumab. We aimed to compare the effectiveness and safety of denosumab with that of BP, with or without calcitonin, in treating HCM. Methods: This retrospective cohort study was conducted at a tertiary hospital from 2017 to 2022 and included 317 patients treated for HCM. Participants were divided into three treatment groups: denosumab, intravenous (IV) BP only, and IV BP combined with calcitonin. The primary outcomes measured were changes in calcium levels and the incidence of hypocalcemia. Analysis of covariance was used to adjust for age, sex, body mass index, creatinine level, type of malignancy, and the use of furosemide and steroids. Results: The mean participant age was 65 years, and 37.5% were female. After adjustment, both denosumab and IV BPs were found to effectively lower calcium levels. Denosumab led to a decrease of 2.0 mg/dL (−15.9%), while IV BP alone resulted in a reduction of 1.8 mg/dL (−13.9%). The largest reduction, of 2.7 mg/dL (−20.9%), occurred with IV BP and calcitonin. Both denosumab and IV BP+calcitonin yielded their lowest calcium levels within 48 hours, whereas the IV BP only group reached a nadir within 72 hours. Despite these differences in treatment effectiveness, hypocalcemia occurred significantly less frequently in the denosumab group compared to the other groups. Conclusion Denosumab and IV BP were similarly effective in reducing calcium levels. However, IV BP combined with calcitonin yielded a more rapid and pronounced decrease.

The increasing number of people living with human immunodeficiency virus (HIV) in Korea has prompted interest in using the national surveillance system as a database for studying their health. To investigate the relationships between socio-demographic and epidemiological characteristics and mortality rates, a nationwide retrospective cohort was formed by integrating surveillance data with the Cause of Death Statistics from Statistics Korea. This integration included incidence reports, epidemiological investigations, and death reports from the surveillance data, enriched with detailed mortality information from the Cause of Death data. The cohort comprised 17,199 adult Korean individuals diagnosed with HIV infection from 1985 to 2020. By the end of 2020, 2,721 of these individuals were confirmed deceased. The sex ratio of the study participants was 14.3:1.0 (male to female), with 78.2% being under 50 years old at the time of diagnosis. Sexual contact was identified as the primary transmission route, accounting for 75.7% of cases. HIV disease emerged as the predominant cause of death, representing two-thirds (1,817 of 2,721) of the fatalities, followed by injuries and trauma, malignancies, and cardiovascular diseases. Recommendations for further cohort studies may be submitted to the Korea Disease Control and Prevention Agency.

Background: A nationwide Rehabilitation at Home Care Pilot Program for patients undergoing lower extremity orthopedic surgeries has been ongoing since 2020. The program was designed to improve clinical outcomes through early mobilization and rehabilitation after discharge. This study aimed to analyze the interim data to assess its effectiveness and suggest improvements, particularly for older patients who are more vulnerable compared to younger patients. Methods: We analyzed the data of 872 patients from seven hospitals. Patients were divided into an older-age group (OG; ≥60 years) and younger-age group (YG; <60 years). The Berg Balance Scale (BBS) and Numeric Rating Scale (NRS) scores for pain were the main outcomes. Results: Participants were categorized into OG (n=801) and YG (n=71). The most common surgeries were knee joint replacement (63.7%) in OG and hip joint replacement in YG (77.5%). It took more days to enroll in the pilot program in OG (4.4 days) than YG (3.2 days). OG showed less improvement in BBS than YG for all surgeries (23.3 vs. 31.9) and hip joint surgery (19.8 vs. 33.5). In patients with hip joint replacement in OG, those with a higher number of comorbidities (≥3) showed less BBS improvement than those with fewer comorbidities (<3). In the pain domain, NRS scores decreased in both groups. Conclusion The postoperative rehabilitation education program appeared to be effective in improving physical function and reducing pain severity, though the improvement was less obvious in older patients who may require a more comprehensive approach compared to younger patients.

Background and Objectives: Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years. Results: There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults. Conclusion The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.

Background and Objectives: This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss. Results: The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults. Conclusion The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.