1.Applying National Whole-genome Sequencing Findings for Rare Diseases in Clinical Practice: The Imperative of a Multidisciplinary Approach
Kyung Sun PARK ; Sunghwan SHIN ; Jong-Ho PARK ; Young-Eun KIM ; Won Kyung KWON ; Min-Kyung SO ; Changhee HA ; Ja-Hyun JANG ; Taeheon LEE ; Chang-Seok KI ; Yoonjung KIM ; Kyung-A LEE ; Inho PARK ; Sejoon LEE ; Hong-Hee WON ; ; Jong-Won KIM
Annals of Laboratory Medicine 2026;46(1):94-103
Background:
As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea.
Methods:
A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC.
Results:
The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%).
Conclusions
Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.
2.Defect Size-Based Comparative Analysis of Treatment Modalities for Esophagojejunal Anastomotic Leakage Following Gastrectomy
Ba Ool SEONG ; Ji Yong AHN ; Juno YOO ; Chang Seok KO ; Sa-Hong MIN ; Chung Sik GONG ; Beom Su KIM ; Moon-Won YOO ; Jeong Hwan YOOK ; Hee Jin CHOI ; In-Seob LEE
Journal of Gastric Cancer 2026;26(2):295-306
Purpose:
Esophagojejunal anastomotic leakage (EJAL) represents a severe postoperative complication following total or proximal gastrectomy. Treatment strategies include conservative management, endoscopic interventions, and surgery; however, comparative data remain limited. This study aimed to compare clinical outcomes of different strategies to identify the optimal approach based on anastomotic defect size.
Materials and Methods:
This retrospective study reviewed 100 patients diagnosed with EJAL between January 2015 and October 2024. Patients were categorized into four groups:conservative management, endoscopic vacuum-assisted closure (E-VAC), other endoscopic treatments, and surgery. The primary outcomes were leakage duration and length of hospital stay after EJAL diagnosis, whereas the secondary outcome was time to C-reactive protein normalization. Subgroup analyses were performed according to defect size.
Results:
Among the 100 patients, 76 were male and 24 were female, with a mean age of 65.7 years. Conservative treatment was the most common modality (53%), followed by other endoscopic treatments (19%), E-VAC (14%), and surgery (14%). In patients with a defect size <1 cm, conservative treatment was associated with significantly shorter leakage duration (P=0.035) and earlier resumption of diet (P=0.029) compared with endoscopic treatment.Among those with defects ≥2 cm, E-VAC demonstrated the most favorable median outcomes across all variables; however, statistical significance was not achieved because of the small sample size.
Conclusions
Conservative treatment appears to be the most effective treatment strategy for EJAL with anastomotic defects <1 cm. For larger defects (≥2 cm), E-VAC may offer clinical benefit, although further studies are needed to confirm its efficacy. These findings highlight the importance of individualized treatment selection based on defect size.
3.Improving prediction of ypT0–1N0 response in rectal cancer: the added value of gross tumor type to magnetic resonance tumor regression grade after chemoradiotherapy in a retrospective cohort study
Kyong-Min KANG ; Mi-Jeong CHOI ; Hong-min AHN ; Heung-Kwon OH ; Duck-Woo KIM ; Jungheum CHO ; Won CHANG ; Young Hoon KIM ; Kyoung Ho LEE ; Yu Kyung JUN ; Yonghoon CHOI ; Sung-Bum KANG
Annals of Surgical Treatment and Research 2026;110(4):237-245
Purpose:
While MRI-based tumor regression grade (mrTRG) has shown promise in evaluating pathologic response to concurrent chemoradiotherapy (CCRT) in rectal cancer, its ability to predict pathologic complete response remains limited.This study aimed to enhance mrTRG’s diagnostic performance in predicting ypT0–1N0 status, a key factor in considering non-radical management after CCRT for locally advanced rectal cancer (LARC).
Methods:
This retrospective study included 430 patients with LARC who underwent radical resection following CCRT at a single referral hospital between April 2018 and September 2024. Multivariable logistic regression was used to identify predictive factors associated with achieving ypT0–1N0 status. The diagnostic performances of mrTRG1–2 alone and in combination with other factors were assessed by comparing sensitivity, specificity, positive-predictive value (PPV), negative-predictive value, and area under the curve (AUC).
Results:
Ninety-three patients (21.6%) achieved ypT0–1N0. In the multivariable analysis, fungating type, cT1–2, and mrTRG1–2 were independent predictors for ypT0–1N0. Integrating mrTRG with gross tumor type yielded the highest AUC of 0.689 among the combined models. For predicting ypT0–1N0, the combination of mrTRG and gross tumor type improved PPV (79.2% vs. 41.5% for mrTRG alone) while also demonstrating enhanced sensitivity compared with ycT0–1N0, the conventional MRI-based predictor (40.9% vs. 22.6%).
Conclusion
This study demonstrated that combining mrTRG and gross tumor type improved the PPV of mrTRG in predicting ypT0–1N0 after CCRT in LARC. Further studies are warranted to validate the role of gross tumor type in refining predictive systems for selecting candidates for non-radical treatment.
4.A unified framework for postoperative complications after gastrectomy for gastric cancer: insights from the Korean Quality Improvement Platform in Surgery program
Jeong Ho SONG ; Chang Seok KO ; Han Hong LEE ; Hong Man YOON ; Hyoung-Il KIM ; In Gyu KWON ; Ji Yeon PARK ; Ji Yeong AN ; Jong Won KIM ; Mi Ran JUNG ; Sang-Il LEE ; Seong Ho KONG ; Sun-Hwi HWANG ; Yun-Suhk SUH ; Sang-Yong SON ; Sang-Uk HAN
Annals of Surgical Treatment and Research 2026;110(5):290-298
Purpose:
Postoperative complications following gastric cancer surgery significantly impact patient outcomes, yet standardized definitions for these events have not been consistently applied across institutions in Korea. This study aimed to develop a consensus-based, standardized complication classification system specific to gastrectomy for gastric cancer as part of the Korean Quality Improvement Platform in Surgery (K-QIPS) initiative.
Methods:
As part of K-QIPS, a dedicated task force team (TFT) was formed with surgical experts from fourteen high-volume hospitals across Korea. The TFT conducted ten formal meetings to review existing literature and international guidelines, and incorporated findings from randomized controlled trials. The final complication list was developed through expert consensus and structured into a standardized framework. A Data Entry Manual was created to support consistent data collection by surgical clinical reviewers.
Results:
The TFT defined specific postoperative complications following gastrectomy for gastric cancer, including anastomotic leakage, duodenal stump leakage, pancreatic fistula, intra-abdominal and luminal bleeding, delayed gastric emptying, and internal hernia. Notably, internal hernia was described in standardized form for the first time. General complications were developed first and overlapped in part with the gastric cancer-specific list. The task force also produced a Data Entry Manual that provides practical instructions to ensure consistency and accuracy in complication reporting.
Conclusion
This nationwide consensus initiative established the first standardized complication classification system for gastric cancer surgery in Korea. The proposed definitions and data entry system are expected to improve complication reporting, enable multicenter research, support surgical quality benchmarking, and ultimately enhance patient outcomes.
5.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.
6.Real-World Efficacy of Intravesical Gemcitabine for BCG-Unresponsive Non–muscle-Invasive Bladder Cancer
Hye Won LEE ; Eui Hyun JUNG ; Kyung Hwan KIM ; Hong Koo HA ; Jong Jin OH ; Seok Ho KANG ; Seung-hwan JEONG ; Hyeong Dong YUK ; Ji Eun HEO ; Won Sik HAM ; Eu Chang HWANG ; Seung Il JUNG ; Wan SONG ; Bumjin LIM ; Bumsik HONG ; Byung Chang JEONG ; Ho Kyung SEO
Cancer Research and Treatment 2026;58(2):591-602
Purpose:
This study aimed to report the real-world outcomes of intravesical gemcitabine for bacillus Calmette–Guérin (BCG)–unresponsive, high-risk, non–muscle-invasive bladder cancer (HR-NMIBC) in Korean patients who were unable or unwilling to undergo radical cystectomy (RC).
Materials and Methods:
This retrospective study included 131 patients (median age, 69 years; 88.5% men) treated with intravesical gemcitabine for BCG-unresponsive HR-NMIBC at nine centers between May 2019 and April 2022. The primary endpoint was 1-year recurrence-free survival (RFS). The secondary endpoints included factors influencing RFS, progression-free survival (PFS), cystectomy- free survival, cancer-specific survival (CSS), overall survival (OS), and safety. Survival analysis was performed using the Kaplan-Meier method, and risk factors for recurrence were assessed using Cox regression models.
Results:
Patients were followed up for a median duration of 25 months, with carcinoma in situ (CIS) in 41.9% of the patients. The 1-year and 2-year RFS rates were 68% and 42%, while the 1-year and 2-year PFS rates were 87% and 77%, respectively. No significant factors influencing RFS were identified. Seventeen patients underwent RC during a median follow-up of 16 months, with the condition in three patients progressing to muscle-invasive disease on final pathological analysis. The 2-year CSS and OS rates were 98% and 97%, respectively. Intravesical gemcitabine was well-tolerated, with only seven patients (5.3%) unable to complete the full induction course.
Conclusion
Our research highlights the potential of intravesical gemcitabine as a viable bladder-sparing treatment option for BCG-unresponsive HR-NMIBC, providing real-world evidence on its safety, efficacy, and tolerability.
7.Status and appropriateness of fasting in the emergency department
Kangbum LEE ; Stephen Gyung Won LEE ; Chang Seob JANG ; Sa Ran LEE ; Hyeonjeong KIM ; Jeong Hwa HONG ; Sumin LEE ; Yeon Kyung KIM
Journal of the Korean Society of Emergency Medicine 2026;37(2):82-88
Objective:
Prolonged fasting has been reported to have a negative effect on patient outcomes. Although fasting is routinely practiced in the emergency department (ED), there is limited evidence on the current status and appropriateness of fasting in the ED. This study examined the status and appropriateness of fasting in the ED and identified the characteristics of patients who experienced unnecessary fasting.
Methods:
A retrospective observational study was performed at an urban ED in Seoul, Korea. The fasting status and characteristics of adult patients who visited the ED and were admitted or discharged between April 1 and April 30, 2022, were analyzed. A checklist for discontinuing fasting in the ED was used to screen for unnecessary fasting.
Results:
Among 2,292 patients who met the study inclusion criteria, all patients were instructed to begin fasting upon ED arrival. Fasting was discontinued by the physician’s order in 300 patients (13.1%). Patients remained fasting for 92.0%±23.2% of their total ED length of stay. Of the 1,577 patients eligible for fasting discontinuation according to the checklist, 249 patients (15.8%) were ordered to discontinue fasting, and 1,328 patients (84.2%) experienced unnecessary fasting.
Conclusion
ED patients spent significant time fasting during their ED length of stay. A high prevalence of unnecessary fasting was identified in the ED.
8.Postoperative Readmission Is Associated With Worse Oncologic Outcomes After Radical Cystectomy for Bladder Cancer: A Multicenter Study of 3,972 Patients
Jungwon PARK ; Jong Ho PARK ; Sangchul LEE ; Seung-Hwan JEONG ; Ja Hyeon KU ; Kyung Hwan KIM ; Jong Kil NAM ; Bumjin LIM ; BumSik HONG ; Wook NAM ; Sung Gu KANG ; Seok Ho KANG ; Tae Gyun KWON ; Tae-Hwan KIM ; Jieun HEO ; Won Sik HAM ; Geehyun SONG ; Ho Kyung SEO ; Wan SONG ; Hyun Hwan SUNG ; Byong Chang JEONG ; Jong Jin OH
Journal of Urologic Oncology 2026;24(1):69-78
Purpose:
Radical cystectomy (RC) is associated with substantial postoperative morbidity, and unplanned readmission remains common despite advances in perioperative management. However, the association between postoperative readmission due to complications and oncologic outcomes after RC for bladder cancer has not been clearly defined. We evaluated the impact of postoperative readmission on overall survival (OS) and cancer-specific survival (CSS) after RC for bladder cancer.
Materials and Methods:
We retrospectively analyzed 3,972 patients who underwent RC for bladder cancer in a multicenter cohort. Postoperative readmission was defined as unplanned hospitalization within 90 days postsurgery due to surgery-related complications. Survival outcomes were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify independent predictors of OS and CSS.
Results:
Among the study population, 916 patients (23.1%) experienced postoperative readmission. Baseline and perioperative characteristics were generally comparable between patients with and without readmission. Kaplan-Meier analyses demonstrated significantly worse OS and CSS among patients who experienced postoperative readmission (both log-rank p<0.001). In multivariable analyses adjusting for clinicopathological factors, postoperative readmission remained independently associated with worse OS (hazard ratio [HR], 1.654; 95% confidence interval [CI], 1.464–1.868; p<0.001) and CSS (HR, 1.761; 95% CI, 1.509–2.055; p<0.001).
Conclusion
Postoperative readmission within 90 days after RC was independently associated with inferior long-term oncologic outcomes. These findings suggest the importance of strategies aimed at preventing postoperative complications and subsequent readmission.
9.Erratum: Guidelines for the Use of Botulinum Toxin in Otolaryngology From the Korean Society of Laryngology, Phoniatrics and Logopedics Guideline Task Force
; Myung Jin BAN ; Chang Hwan RYU ; Joo Hyun WOO ; Young Chan LEE ; Dong Kun LEE ; Minsu KWON ; Yong Tae HONG ; Gil Joon LEE ; Hyung Kwon BYEON ; Seung Ho CHOI ; Seung Won LEE
Clinical and Experimental Otorhinolaryngology 2026;19(2):209-209
10.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.

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