1.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.
2.Topical Application of Probiotic-Derived EGF From Pediococcus pentosaceus Improves UVB-Induced Photoaging in Hairless Mice
Yoon Jin ROH ; Yoon Hwan LEE ; Sun Young YUH ; Hye Won SONG ; Do Yeon KWON ; Byung Chull AN ; Yongku RYU ; Myung Jun CHUNG ; Kui Young PARK
Annals of Dermatology 2026;38(3):191-201
Background:
Epidermal growth factor (EGF) is widely applied in dermatology for its regenerative effects; however, its clinical utility is limited by low stability and high production costs.To overcome these limitations, we developed a novel probiotic-derived epidermal growth factor (pEGF) by engineering Pediococcus pentosaceus CBT SL4 to express and secrete EGF.
Objective:
To investigate the anti-photoaging effects of topical pEGF in a ultraviolet B (UVB)-irradiated mice by assessing histological and molecular changes related to collagen synthesis, extracellular matrix (ECM) remodeling, oxidative stress, and inflammation.
Methods:
SKH1 hairless mice were exposed to UVB for twelve weeks to induce photoaging and treated with topical 10% pEGF cream from week 9 to 12. Skin samples were analyzed using dermoscopy, histology, immunohistochemistry, quantitative real-time polymerase chain reaction, western blotting, and proteomics to evaluate morphological and molecular alterations in ECM components and inflammatory markers.
Results:
Topical pEGF treatment improved skin texture and reduced wrinkles. Histological evaluation revealed that EGF significantly attenuated UVB-induced epidermal thickening and restored collagen density, with the strongest effects observed in the pEGF group. Molecular analysis showed downregulation of matrix metalloproteinases (MMPs; MMP-1, MMP-3), upregulation of collagen (type I collagen, type III collagen) and tissue inhibitors of metalloproteinases (TIMPs; TIMP-1, TIMP-2). Additionally, pEGF reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β) and oxidative stress markers.
Conclusion
pEGF demonstrated potent anti-photoaging effects through ECM restoration, inflammation modulation, and barrier reinforcement. These findings support the therapeutic potential of pEGF as a stable, cost-effective alternative to conventional EGF in dermatological applications.
3.α-MSH Induces Intracellular ROS Generation in Melanoma Cells through NADPH Oxidase-1/4 Activation
Kyuri KIM ; Jihyun YOON ; Hye Yeon KIM ; Kyung-Min LIM
Biomolecules & Therapeutics 2026;34(3):709-721
α-Melanocyte-stimulating hormone (α-MSH) is a key physiological inducer of melanogenesis and melanocyte activation. Reactive oxygen species (ROS) function as secondary messengers in intracellular signaling pathways that regulate α-MSH-mediated melanogenesis. However, the mechanism by which α-MSH induces ROS generation in melanocytes remains incompletely understood. Here, we investigated the sources and regulatory mechanisms of α-MSH-induced ROS in murine B16F10 and human MNT-1 melanoma cells. Confocal microscopy revealed that α-MSH predominantly stimulated cytosolic rather than mitochondrial ROS generation. Western blot analysis showed that α-MSH upregulated the expression of NADPH oxidases NOX1 and NOX4 at early time points, key enzymes involved in cytosolic ROS production. Pharmacological inhibition of NOX1/4 significantly reduced α-MSH-induced ROS levels and melanin content, accompanied by decreased phosphorylation of MITF, a melanogenic transcription factor. These findings indicate that α-MSH is a key physiological inducer of melanogenesis and melanocyte-related signaling in melanoma cells. Our study highlights NOX4, together with NOX1, as potential targets for anti-pigmentation strategies.
4.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.
5.Consensus of Korean Asthma Study Group on Definition of Clinical Remission in Severe Asthma: A Modified Delphi Study
Sun Hye SHIN ; Joon Young CHOI ; Junghee YOON ; Youlim KIM ; Jong Geol JANG ; Ji-Yong MOON ; Chin Kook RHEE ; Kyung Hoon MIN ; Yong Il HWANG ; Yeon-Mok OH ; Seong Yong LIM ;
Tuberculosis and Respiratory Diseases 2026;89(2):215-225
Background:
Asthma remission has recently emerged as an aspirational treatment goal, yet its definition remains inconsistent across studies and expert groups. The absence of a standardized framework hampers its application in clinical practice and research, particularly in Korea where biologics use is rapidly increasing. This study aimed to establish a consensus definition of clinical remission in severe asthma among Korean experts.
Methods:
A two-round modified Delphi survey, followed by a focused third round, was conducted among 28 board-certified pulmonologists from the Korean Academy of Tuberculosis and Respiratory Diseases (KATRD). The questionnaire consisted of six domains and 27 items. Responses were analyzed using agreement rates, interquartile ranges, and content validity ratios to determine consensus levels.
Results:
Consensus was reached on defining clinical remission as a composite of no exacerbations, no systemic corticosteroid use, sustained symptom control (Asthma Control Test ≥20 on at least three occasions over 12 months), and stabilization and optimization of pulmonary function while on maintenance treatment. Experts agreed that pulmonary function should be assessed based on clinical judgment rather than absolute thresholds. Complete remission was additionally defined as fulfilling all clinical remission criteria with normalization of type 2 inflammation (blood eosinophils <300/μL and fractional exhaled nitric oxide <25 ppb).
Conclusion
This Delphi consensus provides a regionally relevant and pragmatic framework for defining remission in severe asthma. These statements may help guide clinical practice, inform guideline development, and support future research on remission as a treatment goal.
6.Integration of Palliative Care in Neurosurgical Critical Care : Insights from a Single-Center Perspective
Nam Hee KIM ; Yejin KIM ; Se Yeon KIM ; Hyoung Suk HAN ; Hye Yoon PARK ; Eun Jin HA ; Shin Hye YOO
Journal of Korean Neurosurgical Society 2025;68(2):213-222
Objective:
: Palliative care is a specialized approach designed to enhance the quality of life for both patients and their families, offering patient-centered care through comprehensive assessment and care planning. However, the integration of palliative care within neurocritical care settings has been relatively understudied. This descriptive study aims to identify the characteristics, palliative care needs, and outcomes of patients referred to palliative care services during admission to the neurosurgical intensive care unit (NS-ICU).
Methods:
: A retrospective analysis of adults admitted to the NS-ICU at a referral hospital between December 2019 and December 2021 was conducted. The study focused on those referred to the inpatient palliative care team with diagnoses of non-traumatic brain hemorrhage, traumatic brain injury, or brain neoplasm. Excluded were patients who died before palliative care consultation or lacked sufficient information. The investigation assessed demographic and clinical characteristics at consultation, along with post-consultation hospital outcomes derived from medical records and interview notes.
Results:
: In this study involving 38 enrolled patients, the median age was 65, with 42.1% females. The most prevalent diagnosis was nontraumatic brain hemorrhage (47.4%). Reasons for palliative care consultation included psychosocial support (95%), goal-of-care discussions (68%), decision-making support (50%), and communication facilitation (39%). The median time from NS-ICU admission to consultation was 3.5 days (interquartile range, 1–8 days), and all interviews involved family members. Key decision topics encompassed mechanical ventilation (23.7%) and tracheostomy (21.1%). Patient preferences for life-sustaining treatment could be estimated in only 47.4% of cases, often resulting in treatment disagreement. Among the 38 patients, 26 (68.4%) died during admission. Before the consultation, full code status, partial code status, and comfort care alone were reported as 32%, 66%, and 2%, respectively; post-consultation, these figures shifted to 11%, 42%, and 47%, respectively.
Conclusion
: Palliative care was predominantly sought for psychosocial support and discussions concerning goals of care. Despite challenges in ascertaining patient treatment preferences, palliative care consultations proved invaluable in aiding family members and facilitating treatment decision-making. Our study suggests the potential integration of palliative care within neuro-critical care, contributing to a heightened utilization of comfort care at the end-of-life.
7.Integration of Palliative Care in Neurosurgical Critical Care : Insights from a Single-Center Perspective
Nam Hee KIM ; Yejin KIM ; Se Yeon KIM ; Hyoung Suk HAN ; Hye Yoon PARK ; Eun Jin HA ; Shin Hye YOO
Journal of Korean Neurosurgical Society 2025;68(2):213-222
Objective:
: Palliative care is a specialized approach designed to enhance the quality of life for both patients and their families, offering patient-centered care through comprehensive assessment and care planning. However, the integration of palliative care within neurocritical care settings has been relatively understudied. This descriptive study aims to identify the characteristics, palliative care needs, and outcomes of patients referred to palliative care services during admission to the neurosurgical intensive care unit (NS-ICU).
Methods:
: A retrospective analysis of adults admitted to the NS-ICU at a referral hospital between December 2019 and December 2021 was conducted. The study focused on those referred to the inpatient palliative care team with diagnoses of non-traumatic brain hemorrhage, traumatic brain injury, or brain neoplasm. Excluded were patients who died before palliative care consultation or lacked sufficient information. The investigation assessed demographic and clinical characteristics at consultation, along with post-consultation hospital outcomes derived from medical records and interview notes.
Results:
: In this study involving 38 enrolled patients, the median age was 65, with 42.1% females. The most prevalent diagnosis was nontraumatic brain hemorrhage (47.4%). Reasons for palliative care consultation included psychosocial support (95%), goal-of-care discussions (68%), decision-making support (50%), and communication facilitation (39%). The median time from NS-ICU admission to consultation was 3.5 days (interquartile range, 1–8 days), and all interviews involved family members. Key decision topics encompassed mechanical ventilation (23.7%) and tracheostomy (21.1%). Patient preferences for life-sustaining treatment could be estimated in only 47.4% of cases, often resulting in treatment disagreement. Among the 38 patients, 26 (68.4%) died during admission. Before the consultation, full code status, partial code status, and comfort care alone were reported as 32%, 66%, and 2%, respectively; post-consultation, these figures shifted to 11%, 42%, and 47%, respectively.
Conclusion
: Palliative care was predominantly sought for psychosocial support and discussions concerning goals of care. Despite challenges in ascertaining patient treatment preferences, palliative care consultations proved invaluable in aiding family members and facilitating treatment decision-making. Our study suggests the potential integration of palliative care within neuro-critical care, contributing to a heightened utilization of comfort care at the end-of-life.
8.Hepatocellular carcinoma in Korea: an analysis of the 2016-2018 Korean Nationwide Cancer Registry
Jihyun AN ; Young CHANG ; Gwang Hyeon CHOI ; Won SOHN ; Jeong Eun SONG ; Hyunjae SHIN ; Jae Hyun YOON ; Jun Sik YOON ; Hye Young JANG ; Eun Ju CHO ; Ji Won HAN ; Suk Kyun HONG ; Ju-Yeon CHO ; Kyu-Won JUNG ; Eun Hye PARK ; Eunyang KIM ; Bo Hyun KIM
Journal of Liver Cancer 2025;25(1):109-122
Background:
s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018.
Methods:
Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018.
Results:
The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%).
Conclusions
Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.
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.Development of the Korean Version of the Meaning in Life Scale for Cancer Patients
Namgu KANG ; Hae-Yeon YUN ; Young Ae KIM ; Hye Yoon PARK ; Jong-Heun KIM ; Sun Mi KIM ; Eun-Seung YU
Psychiatry Investigation 2025;22(3):258-266
Objective:
This study aims to understand the structure of meaning in life among patients with cancer through the validation of the Meaning in Life Scale among Korean patients (K-MiLS) with cancer.
Methods:
From August 2021 to November 2022, participants were recruited from multiple sites in South Korea. Participants completed related questionnaires, including the MiLS, on the web or mobile. Test-retest reliability was assessed between 2 and 4 weeks after the initial assessment. Exploratory and confirmatory factor analyses and Pearson’s correlations were used to evaluate the reliability and validity of the MiLS. A multiple regression analysis was conducted to examine the sociodemographic and disease-related variables correlated with the MiLS. Regarding concurrent validity, a hierarchical regression analysis was performed.
Results:
The results (n=345) indicated that the K-MiLS has a four-factor structure: Harmony and Peace; Life Perspective, Purpose, and Goals; Confusion and Lessened Meaning; and Benefits of Spirituality. Regarding convergent and discriminant validity, K-MiLS was negatively correlated with Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and Fear of Cancer Recurrence Inventory while showing a significantly positive correlation with the Posttraumatic Growth Inventory, Self-Compassion Scale, Functional Assessment of Cancer Therapy-General, and Functional Social Support Questionnaire. Hierarchical regression analysis revealed that the demographic variable influencing MiLS was religious affiliation.
Conclusion
The K-MiLS had a multidimensional four-factor structure similar to that of the original version. It is also a reliable and valid measure for assessing cancer survivors’ meaning in life after a cancer diagnosis.

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