1.HER2-low and ultralow breast cancer: interobserver challenges and lessons from a consensus study
Jiwon KOH ; Yoon Jin CHA ; Eun Yoon CHO ; Ahwon LEE ; Ja Seung KOO ; So Yeon PARK ; Min Hwan KIM ; Jae Ho JEONG ; Gyungyub GONG
Journal of Pathology and Translational Medicine 2026;60(3):331-337
The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.
2.Lycium Radicis Cortex and Its Kukoamine Constituents Attenuate Sarcopenia by Modulating Anabolic and Catabolic Pathways
Jae-Yong KIM ; Rak Ho SON ; Sang-Yoon KIM ; Ji Hoon KIM ; Sunhoo KIM ; Chul Young KIM
Biomolecules & Therapeutics 2026;34(1):189-201
Lycium Radicis Cortex (LRC), derived from the root bark of Lycium chinense Mill., has traditionally been used in East Asian medicine to mitigate heat in the blood and consumptive fever. This study investigates LRC’s effects on skeletal muscle in aged mice subjected to forced exercise and examines the protective properties of its primary constituents, kukoamines A (KA) and B (KB), against dexamethasone (DEX)-induced muscle atrophy. Sixteen-month-old male C57BL/6 mice underwent regular swimming and received oral LRC supplementation for 8 weeks. The effects of KA and KB on muscle atrophy were further explored using C2C12 myotubes treated with DEX. LRC administration significantly enhanced muscle mass, strength, and endurance, while reducing plasma lactate and creatinine levels compared to the control group. LRC also upregulated mRNA expression of MyoD, myogenin, MHC, Akt, and mTOR, and downregulated myostatin, FoxO3a, MuRF1, and atrogin-1 in gastrocnemius and soleus muscles. Furthermore, KA and KB alleviated DEX-induced muscle atrophy in C2C12 myotubes by reducing proteolysis and ROS production, enhancing SOD activity, and improving mitochondrial function. Taken together, LRC may be a useful supplement in exercise-based muscle strengthening and amelioration of muscle disorders, and KA and KB have shown potential as preventive and therapeutic agents for muscle atrophy, indirectly suggesting that the efficacy of LRC is attributed to KA and KB.
3.Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric and Young Adult Patients with Chronic Myeloid Leukemia in Tyrosine Kinase Inhibitor Era: A Study of the Korean Blood and Marrow Transplantation Registry
Hee Young JU ; Hyoung Soo CHOI ; Hyeon Jin PARK ; Keon Hee YOO ; Chuhl Joo LYU ; Ho Joon IM ; Min Kyoung KIM ; Yeung-Chul MUN ; Joon Ho MOON ; Sung-Soo YOON ; Eunyoung LEE ; Jae Hoon LEE ; Je-Hwan LEE ; So Young CHONG ; June-Won CHEONG ; Seunghyun WON ;
Cancer Research and Treatment 2026;58(2):632-641
Purpose:
Chronic myeloid leukemia (CML) in children, adolescents, and young adults is rare and differs from older adults. This study evaluated the outcomes of allogeneic hematopoietic stem cell transplantation (HSCT) in young Korean CML patients during the tyrosine kinase inhibitor (TKI) era.
Materials and Methods:
A retrospective analysis of 35 CML patients aged < 40 years who underwent allogeneic HSCT from 2009 to 2019 was conducted using Korean Blood and Marrow Transplantation Registry data. Patients were grouped by age < 20 years at HSCT (group 1, n=15) and 20-40 years at HSCT (group 2, n=20). Survival outcomes including overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS) were analyzed using the Kaplan-Meier method.
Results:
The median time between diagnosis and HSCT was 8.9 months. All the patients achieved engraftment but platelet recovery was significantly slower in group 1 (p=0.034). Acute and chronic graft-versus-host disease occurred in 54.3% and 34.3%, respectively. Five-year OS, RFS, and EFS rates of total patients were 66.8%, 50.8%, and 47.6%, with better OS was observed in group 1 by multivariable analysis (p=0.048). Disease status at HSCT was a significant predictor of OS (p=0.028), RFS (p=0.003), and EFS (p=0.004). Disease progression occurred in 13 out of 35 patients (37.1%); treatment-related mortality accounted for 63.6% of deaths (7 out of 11).
Conclusion
When performed at a younger age, allogeneic HSCT result in superior outcome in CML. Achieving remission before HSCT is critical for improved outcomes, highlighting the importance of pretransplant remission via optimal TKI strategies and minimal residual disease monitoring.
4.Pressure Changes at the Fifth Metatarsal Regions during Running with Different Foot Strike Patterns
Ji Hwan PARK ; Jin Su KIM ; Jae Keun OH ; Jin Ho YOON
The Korean Journal of Sports Medicine 2026;44(1):49-59
Purpose:
This study aimed to analyze changes in plantar pressure distribution at the fifth metatarsal (M5) during running with different foot strike patterns.
Methods:
Thirty-five healthy adults ran barefoot over a foot scan pressure plate installed in a 10-m shuttle walkway.Each participant completed 10 trials per strike pattern and mean peak pressures at M1–M5 heads and M5 base of the dominant foot was analyzed.
Results:
The mean peak pressures at M2– M5 heads increased progressively from heel to midfoot to forefoot strike (p< 0.05). Significant differences among strike patterns were found at M2–M5 heads (p< 0.05). Post hoc analysis showed that forefoot strike produced significantly higher pressures at M2–M5 heads than heel and midfoot strikes (p< 0.001). At M5, peak pressure at the head increased from heel (14.54±7.82) to midfoot (15.54±7.75) to forefoot strike (19.37±7.37), whereas peak pressure at the base decreased from heel (6.27±1.69) and midfoot strikes (5.85±1.94) to forefoot strike (4.35±1.79). At M5, both the head and base demonstrated significant differences according to strike pattern.
Conclusion
Plantar pressure patterns vary across foot strike types, with forefoot strike producing greater M5 head loading but lower base loading. These findings suggest that forefoot-based low-intensity running may be considered as an early loading option during rehabilitation after Jones fractures, although further clinical studies are needed to confirm its clinical benefits.
5.Resident and nurse attitudes toward a rapid response team in a tertiary hospital in South Korea
Sung Yoon LIM ; Ho Geol WOO ; Jong Sun PARK ; Young-Jae CHO ; Jae Ho LEE ; Yeon Joo LEE
Acute and Critical Care 2025;40(1):29-37
Background:
Residents and nurses who activate rapid response teams (RRTs) are well positioned to offer insights on its effectiveness. Here, we assess such evaluation of RRTs and identify barriers to activation in a 1,400-bed teaching hospital.
Methods:
We conducted a 24-item Likert-scale survey from January to May 2017 among residents and ward nurses with RRT experience. Factor analysis was used to identify the barriers.
Results:
This study comprised 305 nurses and 53 residents, most of whom were satisfied with their RRT experiences. Factor analysis showed that lack of awareness of activation criteria was a major barrier, with only 21.4% and 22.2% participants, respectively, confident about their knowledge of activation protocols. Of the survey respondents, 85.7% reported first contacting the doctor before activating the RRT. Despite the protocol, 66.7% first discussed the decision with other staff, and 71.5% called the RRT when the patient’s condition worsened despite management.
Conclusions
Nurses and residents value RRTs but face barriers in initiation, primarily due to a lack of confidence in applying the activation criteria. Many prefer to consult a doctor or manage the patient before calling the RRT.
7.Machine Learning Prediction of Attachment Type From Bio-Psychological Factors in Patients With Depression
Yoon Jae CHO ; Jin Sun RYU ; Jeong-Ho SEOK ; Eunjoo KIM ; Jooyoung OH ; Byung-Hoon KIM
Psychiatry Investigation 2025;22(4):412-423
Objective:
Adult attachment style is linked to how an individual responds to threats or stress and is known to be related to the onset of psychiatric symptoms such as depression. However, as the current assessment of attachment type mainly relies on self-report questionnaires and can be prone to bias, there is a need to incorporate physiological factors along with psychological symptoms and history in this process. We aimed to predict the measurement of two important types of adult attachment with heart rate variability (HRV), early life stress experience, and subjective psychiatric symptoms.
Methods:
Five hundred eighty-two subjects with depressive disorder were recruited retrospectively from January 2015 to June 2021. The experience of early life stress and psychiatric symptoms were collected, and HRV measures were obtained as input for an ensembled Voting Regressor model of machine learning-based regression models, including linear regression, ElasticNet, Support Vector Machine (SVM), Random Forest, and Extreme Gradient Boosting (XGBoost).
Results:
Model performances evaluated with R-squared score averaged across 30 seeds were 0.377 and 0.188 for anxious- and avoidant-attachment, respectively. Mean absolute error averaged to 13.251 and 12.083, respectively. Shapley value importance analysis indicated that for both attachment types, the most important feature was the trait-anxiety, followed by emotional abuse, state-anxiety or self-reported depressive symptoms, and fear or helplessness felt in the moment of an early life stressor.
Conclusion
Our results provide the evidence base that may be utilized in clinical settings to predict the degree of attachment type using bio-psychological factors.
8.The Korean Organ Transplant Registry (KOTRY): Third Official Adult Heart Transplant Report
Hyo-In CHOI ; Sang Eun LEE ; Junho HYUN ; Darae KIM ; Dong-Ju CHOI ; Eun-Seok JEON ; Hae-Young LEE ; Hyun-Jai CHO ; Hyungseop KIM ; In-Cheol KIM ; Jaewon OH ; Minjae YOON ; Jin Joo PARK ; Jin-Oh CHOI ; Min Ho JU ; Seok-Min KANG ; Soo Yong LEE ; Sung-Ho JUNG ; Jae-Joong KIM
Korean Circulation Journal 2025;55(2):79-96
Background and Objectives:
The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients.
Methods:
Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage.
Results:
The median ages of the recipients and donors were 56.0 and 43.0 years, respectively.Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival.
Conclusions
In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.
9.Radiofrequency Ablation for Recurrent Thyroid Cancers:2025 Korean Society of Thyroid Radiology Guideline
Eun Ju HA ; Min Kyoung LEE ; Jung Hwan BAEK ; Hyun Kyung LIM ; Hye Shin AHN ; Seon Mi BAEK ; Yoon Jung CHOI ; Sae Rom CHUNG ; Ji-hoon KIM ; Jae Ho SHIN ; Ji Ye LEE ; Min Ji HONG ; Hyun Jin KIM ; Leehi JOO ; Soo Yeon HAHN ; So Lyung JUNG ; Chang Yoon LEE ; Jeong Hyun LEE ; Young Hen LEE ; Jeong Seon PARK ; Jung Hee SHIN ; Jin Yong SUNG ; Miyoung CHOI ; Dong Gyu NA ;
Korean Journal of Radiology 2025;26(1):10-28
Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.
10.Machine Learning Prediction of Attachment Type From Bio-Psychological Factors in Patients With Depression
Yoon Jae CHO ; Jin Sun RYU ; Jeong-Ho SEOK ; Eunjoo KIM ; Jooyoung OH ; Byung-Hoon KIM
Psychiatry Investigation 2025;22(4):412-423
Objective:
Adult attachment style is linked to how an individual responds to threats or stress and is known to be related to the onset of psychiatric symptoms such as depression. However, as the current assessment of attachment type mainly relies on self-report questionnaires and can be prone to bias, there is a need to incorporate physiological factors along with psychological symptoms and history in this process. We aimed to predict the measurement of two important types of adult attachment with heart rate variability (HRV), early life stress experience, and subjective psychiatric symptoms.
Methods:
Five hundred eighty-two subjects with depressive disorder were recruited retrospectively from January 2015 to June 2021. The experience of early life stress and psychiatric symptoms were collected, and HRV measures were obtained as input for an ensembled Voting Regressor model of machine learning-based regression models, including linear regression, ElasticNet, Support Vector Machine (SVM), Random Forest, and Extreme Gradient Boosting (XGBoost).
Results:
Model performances evaluated with R-squared score averaged across 30 seeds were 0.377 and 0.188 for anxious- and avoidant-attachment, respectively. Mean absolute error averaged to 13.251 and 12.083, respectively. Shapley value importance analysis indicated that for both attachment types, the most important feature was the trait-anxiety, followed by emotional abuse, state-anxiety or self-reported depressive symptoms, and fear or helplessness felt in the moment of an early life stressor.
Conclusion
Our results provide the evidence base that may be utilized in clinical settings to predict the degree of attachment type using bio-psychological factors.

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