1.Heart Failure Statistics 2025 Update:A Report From the Korean Society of Heart Failure
Chan Joo LEE ; Hokyou LEE ; Kyu-Yong KO ; Min Gyu KONG ; Min Sun KIM ; SungA BAE ; Yuran AHN ; Kyeong-Hyeon CHUN ; Kang-Un CHOI ; Jah Yeon CHOI ; Jungkuk LEE ; Geun U PARK ; Byung Su YOO
International Journal of Heart Failure 2026;8(1):58-73
Background and Objectives:
We evaluated 20-year trends in heart failure (HF) epidemiology in Korea to quantify changes in its burden from 2002 to 2023.
Methods:
A nationwide analysis was conducted using a random 50% sample from the Korean National Health Information Database linked to mortality records (2002–2023). HF was defined using diagnostic codes recorded as a primary or secondary condition. We calculated crude and age-standardized rates of prevalence, incidence, hospitalization, and mortality. Survival was assessed using the Kaplan–Meier method, stratified by inpatient versus outpatient diagnosis.Trends in heart transplantation and left ventricular assist device implantations were also examined.
Results:
By 2023, approximately 1,750,228 individuals had HF (3.41% prevalence). The age-standardized prevalence has more than doubled from 2002 to 2023. The crude incidence increased over time; the age-standardized incidence remained stable in men and declined in women.Hospitalization rates for any cause or secondary HF diagnoses have increased substantially, whereas primary HF hospitalization rates have remained relatively stable. The annual mortality rate in patients with HF was approximately 6.0% in 2023, being markedly higher in older adults.Although short-term survival has improved, particularly in hospitalized patients, long-term survival remains limited. Use of advanced therapies significantly increased.
Conclusions
The burden of HF in Korea has increased substantially over the past two decades, driven primarily by population aging and improved survival rather than increasing age-adjusted incidence. Despite therapeutic advances, hospitalization and long-term mortality rates remain high, highlighting the need for comprehensive HF strategies in aging societies.
2.Ischemic Neuropathy as a Possible Complication of Percutaneous Coronary Intervention: A Case Report
Jisun BAE ; Seungyup SONG ; Dongwook SONG ; Sun IM ; Geun-Young PARK
Journal of Electrodiagnosis and Neuromuscular Diseases 2026;28(1):10-15
Ischemic neuropathy is an uncommon cause of peripheral nerve injury that results from compromised blood flow or oxygen delivery to the vasa nervorum. We report a rare case of multiple ischemic mononeuropathies of the right lower limb that developed after percutaneous coronary intervention (PCI). A 57-year-old man who underwent PCI for ST-elevation myocardial infarction presented with persistent weakness, sensory disturbance, and pain in the right lower limb. Electrodiagnostic studies performed 4 weeks after symptom onset revealed findings consistent with multiple mononeuropathies of the right lower limb. In cases of ischemic neuropathy associated with arterial occlusion, prompt vascular imaging and revascularization of the occluded artery are essential to minimize neurological deficits and optimize motor recovery.
3.Prevalence of HER2-ultralow breast cancer in South Korea: a multicenter study by reassessment of HER2-zero cases
Min Chong KIM ; Eun Yoon CHO ; Hee Jin LEE ; Ji Shin LEE ; Jee Yeon KIM ; Wan Seop KIM ; Chungyeul KIM ; Sun-Young JUN ; Hye Jeong CHOI ; So Mang LEE ; Ahrong KIM ; Ji-Young KIM ; Jeong Yun SHIM ; Gyungyub GONG ; Young Kyung BAE
Journal of Pathology and Translational Medicine 2026;60(2):184-192
This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.
4.Introducing an Inclusive LGBTQ+ Medicine Curriculum: The Experience of Seoul National University College of Medicine
Korean Medical Education Review 2026;28(1):42-48
As sociocultural attitudes in South Korea continue to evolve, the growing visibility of lesbian, gay, bisexual, transgender, and queer (LGBTQ+) individuals highlights an increasing need for medical education that addresses diversity, equity, and inclusion (DEI). In response to this need, Seoul National University College of Medicine (SNUCM) introduced an LGBTQ+ medicine curriculum in 2021. The curriculum aims to prepare future physicians to provide equitable and respectful care to LGBTQ+ patients and to promote improvements in LGBTQ+ health through an affirming clinical approach. The program consists of both required and elective components. A required one-hour session for second-year medical students covers essential terminology, the historical process of depathologizing LGBTQ+ identities, and core principles of non-discriminatory and inclusive clinical care. Students seeking more advanced training may enroll in a four-week elective course, which provides in-depth learning through direct engagement with LGBTQ+ community members and site visits to LGBTQ+-affirming clinical settings. In addition, a ten-week research course is available to interested second-year students. Highly motivated senior-year students may further participate in a five-week advanced clinical placement focused on clinical observation and seminar-based learning. Participants reported high satisfaction with the program and perceived meaningful improvements in their competence in providing LGBTQ+-affirming health care. Broader national implementation of similar curricula will require coordinated collaboration among medical schools and relevant professional and expert organizations to establish shared core educational content and regionally structured clinical clerkship programs. The experience at SNUCM demonstrates both the necessity and the practical feasibility of integrating DEI-focused education, including LGBTQ+ medicine. Such efforts are expected to support the development of physicians who are committed to health equity and capable of delivering high quality, person-centered care free from prejudice.
5.Pluviatolide Attenuates Type I Hypersensitivity through Regulation of Mast Cell Activation
Seon Young KIM ; Jeong Won PARK ; Juhyun SHIN ; Ji-Ae LEE ; Sun-Hee LEEM ; Min Geun JO ; Min Yeong CHOI ; Wahn Soo CHOI ; Keun Young MIN ; Geunwoong NOH ; Sung-Jin BAE ; Yung Hyun CHOI ; Hyuk Soon KIM
Biomolecules & Therapeutics 2026;34(2):413-422
This study examined the inhibitory effects of pluviatolide, a lignan derived from Podophyllum hexandrum, on mast cell activation and IgE-mediated type I hypersensitivity, focusing on FcεRI-dependent and calcium-mediated pathways. Using bone marrowderived mast cells (BMMCs) and rat basophilic leukemia (RBL)-2H3 cells, we found that pluviatolide significantly decreased β-hexosaminidase release and suppressed the expression and secretion of TNF-α and IL-6 in a concentration-dependent manner, without causing cytotoxicity. While we initially hypothesized that it would selectively modulate antigen-specific FcεRI signaling, pluviatolide also inhibited degranulation induced by calcium ionophore and thapsigargin, indicating its effects extend to receptorindependent, Ca2+-dependent activation mechanisms. Immunoblot analyses revealed decreased phosphorylation of proximal kinases (Lyn, Syk), adaptor proteins (LAT, PLCγ1), MAPKs (ERK1/2, JNK, p38), and NF-κB p65. In a passive cutaneous anaphylaxis (PCA) mouse model, oral administration of pluviatolide significantly reduced Evans blue extravasation and mast cell degranulation in ear tissues. These findings demonstrate that pluviatolide suppresses both early and late-phase mast cell responses through multi-nodal inhibition of activation pathways, highlighting its potential as a therapeutic candidate for both IgE-mediated and non-IgE-mediated allergic disorders.
6.Stress Accelerates Depressive-Like Behaviors through Increase of Notch2 Expression in N141I Mutation Presenilin-2 Transgenic Mice
Seung Sik YOO ; Sun Mi GU ; Kyung Tak NAM ; Jeong Soon CHOI ; Yong Sun LEE ; In Jun YEO ; Ji Eun YU ; Sanghyeon KIM ; Dong Won LEE ; Hyeon Joo HAM ; Ju Young CHANG ; Jaesuk YUN ; Dong Ju SON ; Sang-Bae HAN ; Jin Tae HONG
Biomolecules & Therapeutics 2026;34(3):544-555
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.
7.NOVA1 Activation Modulates the Tumor Immune Microenvironment through STING Phosphorylation in Head and Neck Squamous Cell Carcinoma
Sehui KIM ; Hyang Mi KIM ; Jae Min BAE ; Sun Och YOON
Cancer Research and Treatment 2026;58(2):423-433
Purpose:
Neuro-oncological ventral antigen 1 (NOVA1), a neuron-specific pre-mRNA splicing factor, is involved in neuronal development and oncogenesis. NOVA1 overexpression is associated with favorable prognosis in head and neck squamous cell carcinoma (HNSCC) and gastric adenocarcinoma, whereas its downregulation correlates with poor outcomes. High NOVA1 levels in these cancers correlate with increased CD3+ and CD8+ T lymphocyte densities, suggesting involvement in tumor immune-inflammatory signals. This study explores NOVA1's role in regulating the immune-inflammatory cGAS-STING pathway in HNSCC cells and clinical tissues.
Materials and Methods:
HNSCC cell lines (FaDu, YD-10B, SNU-1066, and SNU-1076) were transfected with NOVA1 and poly(dA:dT). Quantitative real-time polymerase chain reaction and Western blot analysis were used to assess gene/protein expression. Enzymelinked immunosorbent assay quantified cytokine levels, and immunoprecipitation assessed protein interactions. Clinical tissue samples from 234 HNSCC patients were analyzed using immunohistochemistry to correlate NOVA1 and STING pathway markers with immune cell infiltration.
Results:
NOVA1 overexpression in HNSCC cells increased phosphorylation of STING (p-STING) without altering cGAS or TBK1. Immunoprecipitation showed an interaction between NOVA1 and p-STING. Overexpression of NOVA1, particularly with poly(dA:dT) treatment, tended to elevate CCL5 and CXCL10 expression. In clinical samples, NOVA1 expression strongly correlated with p-STING levels (r=0.749, p<0.001). Higher NOVA1 and p-STING expressions were linked to increased infiltration of CD3+ T cells, CD8+ T cells, and FOXP3+ regulatory T cells.
Conclusion
NOVA1 modulates the cGAS-STING pathway through STING phosphorylation and associated immune responses in HNSCC, providing a potential therapeutic target for enhancing anti-tumor immunity.
8.Detection Ability of Quality of Life Changes and Responsiveness of the KOQUSS-40 and the EORTC QLQ-C30/STO22 in Patients Who Underwent Gastrectomy: A Prospective Comparative Study
Bang Wool EOM ; Keun Won RYU ; Ji Yeong AN ; Yun-Suhk SUH ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In-Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye-Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Joongyub LEE ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2026;58(1):221-231
Purpose:
The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ).
Materials and Methods:
A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire.
Results:
Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ.
Conclusion
KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.
9.Ten-Year Follow-up Clinical Outcomes and the Role of Adjuvant Chemotherapy in HER2-Positive Patients with Microinvasive Breast Cancer
Yeokyeong SHIN ; Soo-Young LEE ; Hyehyun JEONG ; Jin-Hee AHN ; Kyung Hae JUNG ; Sung-Bae KIM ; Hee Jeong KIM ; Jong Won LEE ; Byung Ho SON ; BeomSeok KO ; Ji Sun KIM ; Il Yong CHUNG ; Hee Jin LEE ; Gyungyub GONG ; Sae Byul LEE ; Jae Ho JEONG
Cancer Research and Treatment 2026;58(1):151-158
Purpose:
Although human epidermal growth factor receptor 2 (HER2) positivity is prevalent in microinvasive breast cancer (MIBC), data focused on HER2-positive MIBC are limited. We investigated the clinical course and long-term outcomes of HER2-positive MIBC and evaluated the role of adjuvant chemotherapy.
Materials and Methods:
The study included patients with curatively resected pT1mi pN0 HER2-positive breast cancer between January 2000 and January 2020. Treatments and survival outcomes, including invasive breast cancer-free survival (IBCFS), distant recurrence-free survival (DRFS), and overall survival (OS) were analyzed.
Results:
The analysis included 799 female patients. The median age was 51 years (range, 23 to 79 years), and 51.6% (n=412) were premenopausal. Multifocality was confirmed in 17.3% (n=138), and estrogen receptor (ER) positivity in 29.8% (n=238). Adjuvant chemotherapy was administered to 17.5% (n=140), with doxifluridine in 96.4% of cases. One patient (0.1%) received trastuzumab. With a median follow-up of 119.0 months (95% confidence interval [CI], 114.0 to 127.0), the 8-year IBCFS, DRFS, and OS were 91.2% (95% CI, 89.1 to 93.3), 97.5% (95% CI, 96.4 to 98.7), and 98.8% (95% CI, 98.0 to 99.6), respectively. No significant differences were observed between patients with and without adjuvant chemotherapy. The lack of differences in IBCFS by chemotherapy was consistent across subgroups, including pre-/postmenopausal patients, grade 1-2/3 tumors, and ER-negative disease.
Conclusion
A clinically meaningful proportion of HER2-positive MIBC patients experience IBCFS events with long-term follow-up. Adjuvant chemotherapy did not improve survival, potentially due to the use of an outdated, ineffective regimen. The role of modern adjuvant regimens, particularly those incorporating HER2-targeted therapy, warrants further exploration.
10.Associated factors of osteoporosis and the impact of osteoporosis on all-cause mortality in incident hemodialysis older patients
Seunghye LEE ; Yoomee KANG ; Yu Ah HONG ; Sung Joon SHIN ; Soon Hyo KWON ; Sungjin CHUNG ; Young Youl HYUN ; Sang Heon SONG ; Jae Won YANG ; Won Min HWANG ; Jang-Hee CHO ; Kyung Don YOO ; In O SUN ; Gang-Jee KO ; Byung Chul YU ; Hyunsuk KIM ; Woo Yeong PARK ; Tae Won LEE ; Dong Jun PARK ; Eunjin BAE ;
Kidney Research and Clinical Practice 2026;45(1):110-119
Background:
With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality.
Methods:
We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis.
Results:
Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality.
Conclusion
We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

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