1.Nationwide Survey on Endoscopic Submucosal Dissection for Early Gastric Cancer in Korea: Results From the Korean College of Helicobacter and Upper Gastrointestinal Research (KCHUGR) 2023 Survey
Jae Yong PARK ; Jeong Hoon LEE ; Tae-Se KIM ; Da Hyun JUNG ; Bong Eun LEE ; Yonghoon CHOI ; Wan-Sik LEE ; Young-Il KIM ; Sun Hyung KANG ; Hyunsoo CHUNG ; Su Jin KIM ; Joon Sung KIM ; Donghoon KANG ; Su Youn NAM ; Seung Han KIM ; Hyo-Joon YANG ; Hyun LIM ; Jin LEE ; Seon-Young PARK ; Seung-Woo LEE ; Sun Moon KIM ; Sam Ryong JEE ; Dae Young CHEUNG ; Chung Hyun TAE ; Seokin KANG ; Sung Chul PARK ; Seung In SEO ; Cheol Min SHIN ; Kee Don CHOI ; Jong Yeul LEE ;
Journal of Gastric Cancer 2026;26(2):169-183
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.
2.MHY5456, an FXR Agonist, Ameliorates Hepatic Steatosis and Fibrosis in a Mouse Model of MASLD
Mi-Jeong KIM ; Hyejin KANG ; Jian YOO ; Sugyeong HA ; Jeongwon KIM ; Byeong Moo KIM ; Da Eun PARK ; Hae Young CHUNG ; Donghwan KIM ; Hyung Ryong MOON ; Ki Wung CHUNG
Biomolecules & Therapeutics 2026;34(3):652-665
Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a global health issue due to its increasing prevalence associated with lifestyle changes and its strong correlation with metabolic syndrome. Farnesoid X receptor (FXR) is a nuclear receptor that plays a pivotal role in regulating bile acid, lipid, and glucose metabolism, making it an attractive therapeutic target for liver and metabolic diseases. In this study, we investigated the effects of MHY5456, a synthetic agonist of FXR, on hepatic metabolism and fibrosis. MHY5456 enhanced the transcriptional activity of FXR in a concentration-dependent manner.Treatment of AC2F rat liver-derived cells with MHY5456 resulted in the downregulation of genes involved in lipid accumulation and an upregulation of mitochondrial-related gene expression. Additionally, MHY5456 significantly reduced oleic acid (OA)-induced lipid accumulation. To assess its anti-fibrotic potential, we tested its effects on transforming growth factor-beta (TGF-β)-induced fibrosis in LX2 human hepatic stellate cells (HSCs). MHY5456 significantly suppressed the expression of fibrosis-related genes and proteins. In vivo, administration of MHY5456 to mice fed a methionine-choline-deficient (MCD) diet alleviated hepatic fibrosis, inflammation, and lipid accumulation. These results show that FXR activation by MHY5456 modulates lipid metabolism and fibrotic pathways, suggesting its potential as a pharmacological candidate for liver and metabolic disorders, including MASLD. Further pharmacological and toxicological studies are needed to confirm its therapeutic relevance.
3.The Prevalence of BRAF Mutation in Papillary Thyroid Carcinoma Decreases Significantly with Increasing Tumor Size
Da Eun LEEM ; Hyunju PARK ; Ji Hyun YOO ; Bo Ram KIM ; Young Lyun OH ; Tae Hyuk KIM ; Sun Wook KIM ; Jae Hoon CHUNG
International Journal of Thyroidology 2026;19(1):95-103
Background and Objectives:
Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association.
Materials and Methods:
We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size.
Results:
The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend <0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older.
Conclusion
In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.
4.Nationwide Survey on Endoscopic Submucosal Dissection for Early Gastric Cancer in Korea: Results From the Korean College of Helicobacter and Upper Gastrointestinal Research (KCHUGR) 2023 Survey
Jae Yong PARK ; Jeong Hoon LEE ; Tae-Se KIM ; Da Hyun JUNG ; Bong Eun LEE ; Yonghoon CHOI ; Wan-Sik LEE ; Young-Il KIM ; Sun Hyung KANG ; Hyunsoo CHUNG ; Su Jin KIM ; Joon Sung KIM ; Donghoon KANG ; Su Youn NAM ; Seung Han KIM ; Hyo-Joon YANG ; Hyun LIM ; Jin LEE ; Seon-Young PARK ; Seung-Woo LEE ; Sun Moon KIM ; Sam Ryong JEE ; Dae Young CHEUNG ; Chung Hyun TAE ; Seokin KANG ; Sung Chul PARK ; Seung In SEO ; Cheol Min SHIN ; Kee Don CHOI ; Jong Yeul LEE ;
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2026;26(1):50-59
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.
5.Categorization of Meibomian Gland Dysfunction Using Lipid Layer Thickness and Meibomian Gland Dropout in Dry Eye Patients: A Retrospective Study
Phil Kyu LEE ; Jae Lim CHUNG ; Da Ran KIM ; Young Chae YOON ; SoonWon YANG ; Woong-Joo WHANG ; Yong-Soo BYUN ; HyungBin HWANG ; Kyung Sun NA ; HyunSoo LEE ; So Hyang CHUNG ; Eun Chul KIM ; YangKyung CHO ; Hyun Seung KIM ; Ho Sik HWANG
Korean Journal of Ophthalmology 2024;38(1):64-70
Purpose:
In the present study, we determined the prevalence of obstructive meibomian gland dysfunction (MGD), hyposecretory MGD, grossly normal MG, and hypersecretory MGD in patients with dry eye syndrome using lipid layer thickness (LLT) and MG dropout.
Methods:
Eighty-eight patients with dry eye syndrome were included in the study. Patients were categorized into four groups according to the LLT and weighted total meiboscore. The proportion of patients in each group was calculated. The age, sex, Ocular Surface Disease Index, LLT, Schirmer, tear film breakup time, cornea stain, weighted total meiboscore, expressibility, and quality of meibum were compared between the four groups.
Results:
Fifteen eyes (17.0%) had obstructive MGD, two eyes (2.3%) had hyposecretory MGD, 40 eyes (45.5%) had grossly normal MG, and 17 eyes (19.3%) had hypersecretory MGD. The obstructive MGD group was younger than the grossly normal MG group. In obstructive MGD, the ratio of men to women was higher than that of the other groups. However, Ocular Surface Disease Index, Schirmer, tear film breakup time, and corneal stain did not show statistically significant differences between the four groups. The meibum expressibility of the hyposecretoy MGD group was worse than those of the other groups. The meibum expressibility of the hyposecretoy MGD group was poor than those of the obstructive and hypersecretory MGD group.
Conclusions
This categorization was expected to help determine the best treatment method for dry eye syndrome, according to the MG status.
6.In Vivo Human Lacrimal Gland Imaging Using an Ultrasound Biomicroscopy
Chanjoon PARK ; Da Ran KIM ; Young Chae YOON ; Soonwon YANG ; Woong-Joo WHANG ; Yong-Soo BYUN ; Hyung Bin HWANG ; Kyung Sun NA ; Hyun Soo LEE ; So Hyang CHUNG ; Eun Chul KIM ; Yang Kyung CHO ; Hyun Seung KIM ; Hosik HWANG
Korean Journal of Ophthalmology 2024;38(3):227-235
Purpose:
In the present study, we introduce human lacrimal gland imaging using an ultrasound biomicroscopy (UBM) with a soft cover and show their findings
Methods:
The representative UBM findings of palpebral lobes in seven subjects (four with non-Sjögren dry eye syndrome, one with Sjögren syndrome, and two healthy subjects) were described in this study. To prolapse the palpebral lobe, the examiner pulled the temporal part of the upper eyelid in the superotemporal direction and directed the subject to look in the inferonasal direction. We scanned the palpebral lobes longitudinally and transversely using UBM. We used an Aviso UBM with a 50 MHz linear probe and ClearScan.
Results:
In UBM of two healthy subjects, the echogenicity of the lacrimal gland was lower than that of the sclera and homogeneous. But the parenchyma of a patient with Sjögren dry eye syndrome was quite inhomogeneous compared to the healthy subjects. In two patients with dry eye syndrome, we were able to observe some lobules in the parenchyma. We could find excretory ducts running parallel at the surface of the longitudinal section in some subjects. In the longitudinal UBM scan of a subject, we observed a tubular structure at a depth of 1,500 μm that was considered a blood vessel. It ran from the superonasal to the inferotemporal direction. In a subject, we observed a large cyst beneath the conjunctiva.
Conclusions
Lacrimal gland imaging using UBM has both advantages of optical coherence tomography and sonography, and could be useful for evaluating dry eye syndrome.
8.Imaging Surveillance After Breast-Conserving Surgery for Cancer With Acellular Dermal Matrix Reconstruction
Da Won JUNG ; Jin CHUNG ; Ji Min KIM ; Eun Suk CHA ; Jeoung Hyun KIM
Korean Journal of Radiology 2024;25(11):992-1002
Objective:
The aim of this study was to investigate postoperative imaging findings of patients who underwent breastconserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images.
Materials and Methods:
This study included 201 women (age range: 28–81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®.
Results:
MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up.
Conclusion
Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient’s history of MegaDerm® insertion when in doubt.
9.Imaging Surveillance After Breast-Conserving Surgery for Cancer With Acellular Dermal Matrix Reconstruction
Da Won JUNG ; Jin CHUNG ; Ji Min KIM ; Eun Suk CHA ; Jeoung Hyun KIM
Korean Journal of Radiology 2024;25(11):992-1002
Objective:
The aim of this study was to investigate postoperative imaging findings of patients who underwent breastconserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images.
Materials and Methods:
This study included 201 women (age range: 28–81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®.
Results:
MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up.
Conclusion
Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient’s history of MegaDerm® insertion when in doubt.
10.Clinical Manifestations of Malignant Struma Ovarii: A Retrospective Case Series in a Tertiary Hospital in Korea
Hyun Jin RYU ; Da Eun LEEM ; Ji Hyun YOO ; Tae Hyuk KIM ; Sun Wook KIM ; Jae Hoon CHUNG
Endocrinology and Metabolism 2024;39(3):461-467
Background:
Malignant struma ovarii (MSO) is a very rare disease in which thyroid cancer originates from the ovary. Because it is rare for endocrinologists to encounter patients with MSO, endocrinologists may have a limited understanding of the disease. Therefore, we analyzed and introduced its incidence and clinical course in a tertiary hospital in Korea.
Methods:
We retrospectively investigated the clinical data of 170 patients who underwent surgery for struma ovarii at the Department of Obstetrics and Gynecology of Samsung Medical Center from 1994 to May 2023.
Results:
Among 170 patients with struma ovarii, 15 (8.8%) were diagnosed with MSO. The median age of patients with MSO was 48 years (range, 30 to 74), and the median tumor size was 3.3 cm (range, 0.5 to 11.0). Papillary thyroid carcinoma (46.7%) was the most common subtypes followed by follicular thyroid carcinoma (26.7%). All patients were diagnosed after surgery, with no predictions from preoperative imaging. The surgical extent of gynecological surgery was variable. Four patients (26.7%) underwent thyroidectomy for thyroid cancer, while one underwent total thyroidectomy and radioactive iodine therapy for MSO with peritoneal metastasis. Except for one patient who underwent hemithyroidectomy, thyroid stimulating hormone suppression therapy was performed in four patients. Only 53% of MSO patients were consulted by an endocrinologist. With a median follow-up period of 33 months (range, 4 to 156), 11 patients remained disease-free, one experienced progression with peritoneal seeding, and the remaining one was in treatment. There have been no recurrences or deaths due to MSO.
Conclusion
An endocrinologist should be involved in establishing a therapeutic plan for MSO, for which the overall prognosis is generally favorable.

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