1.Epidemiology of Gastric Cancer in Korea (1999–2022): Incidence, Survival, and 5-Year Conditional Relative Survival
Ki Bum PARK ; Mee Joo KANG ; Johyun HA ; Eun Hye PARK ; E Hwa YUN ; Hye-Jin KIM ; Kyu-Won JUNG ; Han Hong LEE
Journal of Gastric Cancer 2026;26(1):4-15
Purpose:
This study evaluated long-term trends in gastric cancer epidemiology and survival with a focus on conditional relative survival (CRS).
Materials and Methods:
Using the Korea Central Cancer Registry, we analyzed 665,184 patients who were newly diagnosed with gastric cancer between 1999 and 2022.The study period was divided into four intervals: Period I (1999–2005), Period II (2006–2011), Period III (2012–2017), and Period IV (2018–2022). Temporal trends in the incidence and mortality were assessed using crude and age-standardized rates. Relative survival was estimated using the Ederer II method, and the 5-year CRS was calculated according to the survival duration after diagnosis.
Results:
The incidence of gastric cancer increased until 2011 and subsequently declined, with a marked decrease observed in 2020. Individuals aged ≥70 years consistently had the highest incidence rates. Mortality rates showed a sustained decline throughout the study period. The overall 5-year relative survival improved from 69.8% in Period II to 78.4% in Period IV. The 5-year CRS increased from 86.1% at 1 year after diagnosis to 96.3% at 5 years.Patients with localized stage maintained a 5-year CRS above 95% at 1 year after diagnosis, whereas those with regional and distant stages showed 5-year CRS that consistently remained below 95%.
Conclusions
The incidence and mortality rates of gastric cancer in Korea have declined over the past two decades, accompanied by improved survival outcomes. The CRS analysis suggests that long-term follow-up is warranted, with the optimal duration varying according to patient characteristics.
2.Obstetric Outcomes of Jehovah’s Witness Women Under Patient Blood Management: A Single-center, Propensity Score–Matched Cohort Study in Korea
Jeong-Won OH ; Seug Yun YOON ; Jeong Jae LEE ; Kyu Yeon CHOI ; Seong Soon KWON
Journal of Preventive Medicine and Public Health 2026;59(2):143-151
Objectives:
Patient blood management (PBM) is increasingly recognized as an essential strategy in obstetric care for reducing transfusion-related risks and improving maternal safety. Jehovah’s Witness (JW) women, who categorically refuse blood transfusion, represent a unique clinical population in which to evaluate the effectiveness of PBM. This study aimed to assess obstetric outcomes of JW women compared with non-JW women at a PBM-based center in Korea.
Methods:
We retrospectively reviewed delivery outcomes and PBM practices among JW women (n=205) with singleton pregnancies and non-JW women (n=601) who were matched at a 1:3 ratio using propensity scores at Soonchunhyang University Seoul Hospital between 2018 and 2023. The primary outcomes included obstetric morbidities, with particular attention to complications related to postpartum hemorrhage and the interventions used for its management.
Results:
JW women were more likely to receive intravenous iron administration (7.3 vs. 2.8%, p=0.008) and had higher hemoglobin (Hb) levels during the first trimester (12.6±1.1 vs. 11.8±3.4 g/dL, p=0.012) than non-JW women. Blood loss during cesarean section and the incidence of severe postpartum anemia (Hb <7 g/dL) were lower among JW women; however, these differences did not reach statistical significance. In the hemorrhage-related high-risk subgroup, JW women were managed according to PBM protocols without transfusion, and their obstetric outcomes were comparable to those observed in non-JW women.
Conclusions
This study identified no significant differences in hemorrhage-related obstetric outcomes between JW and non-JW women at a PBM-based center. The systematic application of PBM enables safe delivery in transfusion-restricted settings and may reduce reliance on blood transfusion while maintaining maternal safety.
3.Correlation and Agreement Between Transcutaneous Oxygen Pressure and Toe Pressure in Patients with Diabetic Foot Ulcers
Kyu-Il LEE ; Yu-Kyeong YUN ; Seung-Kyu HAN ; Kyung-Chul MOON ; Sik NAMGOONG ; Seong-Ho JEONG ; Eun-Sang DHONG
Journal of Wound Management and Research 2026;22(1):14-20
Background:
Adequate tissue oxygenation is a key determinant of diabetic foot ulcer (DFU) outcomes. Though transcutaneous oxygen pressure (TcPO2) is the gold standard for evaluating tissue oxygenation, its limited availability restricts routine clinical use. Consequently, toe pressure is frequently utilized as a practical surrogate; however, the direct correlation between these two modalities has yet to be rigorously investigated. This study aimed to assess the correlation and agreement between TcPO2 and toe pressure in patients with DFUs.
Methods:
A retrospective review was conducted on 837 DFU patients who received simultaneous TcPO2 and toe pressure assessments. The correlation between the two tests was analyzed using the Pearson correlation coefficient, and agreement was evaluated using Bland–Altman analysis. To aid interpretation, a scatterplot and Bland–Altman plot were generated.
Results:
TcPO2 and toe pressure demonstrated a strong correlation (R=0.66; 95% confidence interval, 0.62 to 0.70; P<0.001). Bland–Altman analysis showed a mean bias of 26.9 mmHg (standard deviation of differences, 28.8 mmHg; 95% limits of agreement, −28.9 to 82.6 mmHg) between toe pressure and TcPO2, reflecting limited agreement and increased variability at higher perfusion levels.
Conclusion
TcPO2 and toe pressure are strongly correlated. However, they are not interchangeable, particularly in DFU patients with high tissue perfusion.
4.Diagnostic and prognostic performance of PAK1 methylation in patients with hepatocellular carcinoma undergoing liver transplantation
Shin HWANG ; Hyo Jung KO ; Eunyoung TAK ; Kyoung-Jin LEE ; Yun-Kyu LEE
Clinical Transplantation and Research 2026;40(1):104-115
Background:
DNA methylation is under investigation as an early diagnostic biomarker for cancers such as hepatocellular carcinoma (HCC). p21-activated protein kinase 1 (PAK1) demonstrates a high methylation tendency in HCC. We assessed the diagnostic and prognostic performance of PAK1 methylation in liver transplantation (LT) recipients with and without HCC.
Methods:
To assess PAK1 methylation, stored pretransplant blood samples from LT recipients were analyzed by droplet digital polymerase chain reaction.
Results:
This study included 274 patients with HCC and 100 control patients without the disease. Ten-year survival rates in the HCC and control groups were 60.5% and 80.6%, respectively (P=0.001). The 10-year HCC recurrence rate was 39.0%. Ten-year survival rates in the HCC recurrence and nonrecurrence groups were 13.3% and 91.2%, respectively (P<0.001); median PAK1 methylation levels in the control and HCC groups were 50.0 and 108.0 copies (P=0.102). The area under the receiver operating characteristic curve was 0.599, and the Youden J index was 0.199, indicating 57.9% sensitivity and 62.0% specificity at a cutoff of 78 copies. With a cutoff of 5 copies, sensitivity was 94.1% and specificity was 14.0%. The positive likelihood ratio was 1.09 and the negative likelihood ratio was 0.42, indicating diagnostic accuracy below α-fetoprotein and protein induced by vitamin K absence or antagonist-II. PAK1 cutoffs of 5 and 10 copies did not affect HCC recurrence, but a cutoff of 2 copies appeared associated with lower recurrence.
Conclusions
These data suggest that PAK1 methylation is not a clinically useful biomarker for HCC in LT recipients. New DNA methylation biomarkers are required for early diagnosis.
5.Cohort profile: Korean Varicella Immunization Monitoring (K-VIM) Scheme: a national cohort of children born 2011–2022
Young Kyu SHIM ; Young Hwa LEE ; Young June CHOE ; Yoonsun YOON ; Yun-Kyung KIM
Epidemiology and Health 2026;48(1):e2026005-
Varicella, caused by the varicella-zoster virus, was once nearly universal in childhood before the advent of vaccination and may lead to severe complications and even fatalities. Monitoring varicella vaccine effectiveness is crucial yet often overlooked in settings with limited surveillance infrastructure. The Korean Varicella Immunization Monitoring (K-VIM) Scheme was established to address this gap by assembling a national, insurance-based birth cohort of children born between 2011 and 2022 (n=4,505,165). This cohort leverages comprehensive healthcare databases in Korea to capture vaccination records, medical visits, and varicella infection outcomes for virtually all children within the target birth years. We describe the enrollment and key characteristics of the K-VIM cohort, including vaccination coverage, demographic features, and varicella incidence to date. The structure and completeness of Korea’s national health insurance and immunization registries enable robust longitudinal tracking of varicella infections among vaccinated versus unvaccinated children. Early findings demonstrate distinct patterns in infection rates and disease severity according to vaccination status. The K-VIM Scheme provides a foundation for ongoing epidemiological studies of varicella vaccine effectiveness and public health impact in Korea. Future plans include evaluating the long-term effects of varicella vaccination, including potential impacts on herpes zoster incidence, using diverse study designs to strengthen causal inference and inform immunization policy.
6.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
7.Consensus Statements on Tinnitus Treatment: A Delphi Study by the Korean Tinnitus Study Group
Junhui JEONG ; Ho Yun LEE ; Oak-Sung CHOO ; Hantai KIM ; Kyu-Yup LEE ; Jae-Jin SONG ; Jae-Hyun SEO ; Yoon Chan RAH ; Jae-Jun SONG ; Eui-Cheol NAM ; Shi Nae PARK ; In Seok MOON ; Hyun Joon SHIM
Journal of Korean Medical Science 2025;40(18):e75-
Background:
Tinnitus is a bothersome condition associated with various mechanisms of action. Although treatment methods vary according to these mechanisms, standardized guidelines would benefit both patients and clinicians. We conducted a Delphi study, a method that collects expert opinions through multiple rounds of questionnaires, to reach a consensus on tinnitus treatment with professional experts.
Methods:
A two-round modified Delphi survey was conducted to develop a clinical consensus on tinnitus treatment. The experts scored each statement on a scale of 1 (highest disagreement) to 9 (highest agreement) for their level of agreement on tinnitus treatment.Consensus was defined when 75% or more of the participants scored 7–9, and 15% or less scored 1–3. To ensure reliability of the responses, the content validity ratio and Kendall’s coefficient of concordance were evaluated.
Results:
Approximately 19 of 31 statements reached a consensus. All 3 statements reached a consensus regarding the candidates for treatment. Regarding treatment, 3 of 8 statements on medication, 2 of 2 statements on tinnitus retraining therapy/cognitive behavioral therapy, and 5 of 7 statements on auditory rehabilitation reached a positive consensus. Although all 6 statements regarding miscellaneous treatment reached a consensus, most were negatively agreed. For treatment with neuromodulation, none of the 5 statements reached a consensus.
Conclusion
The experts reached a high level of consensus on treatment candidates, tinnitus retraining therapy/cognitive behavioral therapy, and auditory rehabilitation in this modified Delphi study. The results of this study can provide beneficial and practical information for clinicians regarding the treatment of tinnitus.
8.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
9.Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences
Kyu Sung CHOI ; Chanrim PARK ; Ji Ye LEE ; Kyung Hoon LEE ; Young Hun JEON ; Inpyeong HWANG ; Roh Eul YOO ; Tae Jin YUN ; Mi Ji LEE ; Keun-Hwa JUNG ; Koung Mi KANG
Korean Journal of Radiology 2025;26(1):54-64
Objective:
To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.
Materials and Methods:
This study included 150 participants (51 male; mean age 57.3 ± 16.2 years). Each group of 50 participants was scanned using one of three 3T scanners from three different vendors. Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1- and T2-weighted and 3D gradient-echo sequences. Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images. The scan times of Accel-DL and conventional MRI methods were compared. Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5- and 3-point scales). Inter-reader agreement was assessed using Fleiss’ kappa coefficient. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.
Results:
Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%–51.3%). Accel-DL improved overall image quality (3.78 ± 0.71 vs. 3.36 ± 0.61, P < 0.001), structure delineation (2.47 ± 0.61 vs. 2.35 ± 0.62, P < 0.001), and artifacts (3.73 ± 0.72 vs. 3.71 ± 0.69, P = 0.016). Inter-reader agreement was fair to substantial (κ = 0.34–0.50). SNR and CNR increased in Accel-DL (82.0 ± 23.1 vs. 31.4 ± 10.8, P = 0.02; 12.4 ± 4.1 vs. 4.4 ± 11.2, P = 0.02). Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus. Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 ± 0.29).
Conclusion
Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.
10.Impact of Nusinersen on the Health-Related Quality of Life and Caregiver Burden in Patients with Spinal Muscular Atrophy with Symptom Onset before the Age of 6 Months
Yun Jeong LEE ; Hyunwoo BAE ; Young Kyu SHIM ; Jae So CHO ; Jong Hee CHAE ; Soonhak KWON
Annals of Child Neurology 2025;33(2):39-47
Purpose:
This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments.
Methods:
A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed.
Results:
Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities.
Conclusion
The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.

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