1.Gestational Age and Neurodevelopmental Outcomes in Preterm Children at Early Preschool Age: A Longitudinal Multidomain Logistic Modeling Study
Ji Na YANG ; Ye Kyeng SEO ; Dong Hyun KIM ; Nam Hun HEO ; Soo A KIM ; Jun Hwan SONG ; Seung Soo KIM
Annals of Child Neurology 2026;34(2):109-119
Purpose:
Preterm birth remains a leading cause of long-term neurodevelopmental impairment, yet early evaluations frequently underestimate subsequent deficits. This study examined longitudinal neurodevelopmental trajectories across gestational age groups and identified predictors of developmental delay.
Methods:
A retrospective cohort of 532 preterm children, stratified by gestational age, was followed from the neonatal period to early preschool age. Neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant and Toddler Development, Third Edition at 8–12 months (n=481), 13–24 months (n=118), and 25–42 months (n=100). Longitudinal trajectories were analyzed using general linear models, and predictors of developmental delay were identified through multivariable logistic regression.
Results:
During the first year, motor scores differed significantly across gestational age groups, with extremely preterm infants showing the lowest values. By the third to fourth years of life, cognitive and language scores diverged markedly, with extremely preterm children exhibiting the steepest decline and additional deficits in motor and adaptive behavior domains. Lower gestational age remained an independent predictor of both cognitive and language delay at early preschool age, while no independent predictors were identified for motor, social-emotional, or adaptive behavior outcomes.
Conclusion
Neurodevelopmental outcomes in preterm children follow dynamic, domain-specific trajectories influenced by gestational age and developmental timing. Motor delays are most evident in infancy, whereas cognitive and language impairments emerge by early preschool age. Gestational age remains a consistent predictor of later delay, emphasizing the need for longitudinal, gestational age–stratified monitoring and early, targeted intervention.
2.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.
3.Long-term Immunogenicity of the 13-valent Pneumococcal Conjugate Vaccine during Adjuvant Chemotherapy in Patients with Gastric and Colorectal Cancer: A 5-Year Follow-up of a Randomized Controlled Trial
Hyeon-Jong KIM ; Hyunjin BANG ; Hyun-Jung SHIM ; Jun Eul HWANG ; Sang-Hee CHO ; Ik-Joo CHUNG ; Seung Ji KANG ; Jong Gwang KIM ; Seung-Hoon BEOM ; A-Yeung JANG ; Joon Young SONG ; Woo Kyun BAE
Cancer Research and Treatment 2026;58(1):61-70
Purpose:
Current guidelines recommend vaccination at least 2 weeks before chemotherapy initiation to optimize the immune response despite limited evidence. Our previous study indicated no differences in short-term immune response for the 13-valent pneumococcal conjugate vaccine (PCV13) according to the vaccination timing. This study aims to investigate the long-term efficacy of PCV13 and clinical factors associated with the respective antibody response.
Materials and Methods:
Patients with gastric or colorectal cancer who received adjuvant chemotherapy were enrolled and divided into two groups: vaccinated 2 weeks before chemotherapy (arm A) and vaccinated concurrently with chemotherapy (arm B). Serum samples were collected before vaccination and in one month, 3 years, and 5 years. Immune responses were measured using enzyme-linked immunosorbent assay and multiplex opsonophagocytosis assay.
Results:
Including 63 patients, both groups showed an initial increase in the geometric mean titers of opsonophagocytic activity and the geometric mean concentrations of serotype-specific IgG levels after one month, followed by a decline at 3 and 5 years, particularly for serotypes 1, 14, 18C, and 19A. Despite the decline, global protection was maintained for 5 years, although global response decreased. The two arms did not show significant differences in immunogenicity nor in factors such as vaccination timing, age, cancer type, or chemotherapy regimen.
Conclusion
Vaccination timing is not a significant factor for the immunogenicity of PCV13 in cancer patients undergoing adjuvant chemotherapy. Global protection against pneumococcal infection was sustained for > 5 years, and global response remained in over half of patients.
4.Clinical Guideline for the Use of Biodegradable Rectal Spacers During Radiotherapy for Prostate Cancer
Hyun Ho HAN ; Jong Kyou KWON ; Do Kyung KIM ; Jin Hyung JEON ; Chan Woo WEE ; Jae Ho CHO ; Ji Hee JUNG ; A Young YOO ; Jae Young JOUNG ; Gee Hyun SONG ; Seung Ju LEE ; Won PARK ; Chan Kyo KIM ; Young Seok KIM ; Yeon Joo KIM ; Ah Ram CHANG ; Jae Sik KIM ; Sung Hwan BAE ; Byoung Kyu HAN ; Kang Su CHO
Journal of Urologic Oncology 2026;24(1):3-12
Purpose:
Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT.
Materials and Methods:
This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system.
Results:
Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised.
Conclusion
Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.
5.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.
6.Health system disruption and oncologic consequences: a retrospective observational study of South Korea’s 2024 medical walkout
Seung Ho SONG ; Chang Hyun KIM ; Soo Yeun PARK
Journal of Yeungnam Medical Science 2026;43(1):4-
Background:
In February 2024, a sudden government policy to drastically increase medical school admissions triggered the mass resignations of medical trainees across South Korea, severely disrupting hospital operations. This study aimed to evaluate the impact of the resulting healthcare workforce disruptions on short-term clinical outcomes and the timing of colorectal cancer surgeries.
Methods:
This retrospective comparative study analyzed patients with colorectal cancer treated at two national university hospitals in Daegu and Gwangju, South Korea. Patients who first visited the colorectal surgery department between March and August of 2023 and 2024 were included. Data from 2020 to 2022 were used for extended comparisons. The primary outcome was the interval from initial outpatient visit to surgery. Secondary outcomes included treatment modality distribution, tumor staging, and postoperative complications.
Results:
A total of 895 patients in 2023 and 853 in 2024 were included. In 2024, only 39.5% of patients (337/853) underwent upfront surgery compared to 63.5% (569/895) in 2023. The median time to surgery increased from 30 days (interquartile range [IQR], 22–44 days) to 52 days (IQR, 30–72 days) (p=0.001). Clinical T3–4 tumors increased from 49.9% to 59.3% (p=0.018), lymph node-positive cases increased from 25.9% to 51.3% (p=0.001), and postoperative complication rates increased from 12.0% to 28.2% (p=0.001).
Conclusion
The abrupt healthcare workforce crisis in early 2024 significantly delayed colorectal cancer surgeries and was associated with worse short-term oncologic outcomes. These findings highlight the critical importance of maintaining a stable healthcare workforce to protect access to timely cancer care.
7.Impact of obesity on renal function in elderly Korean adults: a national population-based cohort study
Jihyun YANG ; Hui Seung LEE ; Chi-Yeon LIM ; Hyunsuk KIM ; Sungjin CHUNG ; Soon Hyo KWON ; Jang-Hee CHO ; Kyung Don YOO ; Woo Yeong PARK ; In O SUN ; Byung Chul YU ; Gang-Jee KO ; Jae Won YANG ; Won Min HWANG ; Sang Heon SONG ; Sung Joon SHIN ; Yu Ah HONG ; Eunjin BAE ; Young Youl HYUN
Kidney Research and Clinical Practice 2026;45(1):65-76
Background:
Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly.
Methods:
We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease.
Results:
During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001).
Conclusion
In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.
8.Hemodynamic stability with remimazolam versus propofol during anesthesia induction in hypertensive patients: a meta-analysis with trial sequential analysis of randomized controlled trials
Seung Eun SONG ; Sang Hun KIM ; Seongtae JEONG ; Hyun KANG ; Hyun Jung KIM
Korean Journal of Anesthesiology 2026;79(3):306-317
Background:
Hypertensive patients tend to have an increased risk of hypotension during anesthesia induction, which can result in adverse outcomes. This study aimed to compare hemodynamic stability with remimazolam versus propofol in hypertensive patients.
Methods:
This meta-analysis analyzed randomized controlled trials investigating the hemodynamic outcomes of remimazolam versus propofol during anesthesia induction in hypertensive adults. A systematic search of electronic databases was conducted in November 2024.
Results:
Six studies were included in the final analysis. The administration of remimazolam significantly lowered the risk of hypotension (risk ratio [RR] = 0.711, 95% CI [0.545–0.929], I2 = 67.54%) and bradycardia (RR = 0.256, 95% CI [0.101–0.649], I2 = 0.0%). It also resulted in a higher minimum mean arterial pressure (mean difference [MD] = 9.023 mmHg, 95% CI [0.243–17.802], I2 = 97.50%) and higher minimum heart rate (MD = 7.200 beats/min, 95% CI [1.960–12.441], I2 = 86.40%). Despite these findings, substantial heterogeneity was observed in continuous outcomes. The trial sequential analysis revealed that none of the outcomes reached the required information size.
Conclusions
The administration of remimazolam showed a trend toward superior hemodynamic stability compared with propofol during anesthesia induction in hypertensive patients, especially in minimizing the incidence of hypotension and bradycardia. However, the trial sequential analysis results remain inconclusive, the current evidence is limited by small sample sizes, and larger trials are needed to confirm our findings.
9.Optimal use and cycling strategies of Janus kinase inhibitors in ulcerative colitis: current evidence and clinical implications from the KASID Guidelines Task Force Team
Seung Min HONG ; Dong Hyun KIM ; June Hwa BAE ; Seung Yong SHIN ; Eun Mi SONG ; Ji Eun KIM ; Young Joo YANG ; Jiyoung YOON ; Sang-Bum KANG ; Eun Soo KIM ; Seong-Eun KIM ; Seong-Jung KIM ; Jun LEE ; Soo-Young NA ; Soo Jung PARK ; Sang Hyoung PARK ; Miyoung CHOI ; Myung Ha KIM ; Won MOON ; Sung-Ae JUNG ;
Intestinal Research 2026;24(1):27-37
Janus kinase (JAK) inhibitors are an important treatment option for ulcerative colitis, providing rapid onset of action, oral administration, and efficacy even after biologic failure. The 3 approved agents—tofacitinib, filgotinib, and upadacitinib—differ in JAK isoform selectivity, leading to clinically meaningful differences in efficacy and safety. Evidence from network meta-analyses, clinical trials, and real-world studies consistently shows that upadacitinib provides the highest efficacy for induction and maintenance of remission, whereas filgotinib demonstrates the most favorable safety profile. The strong efficacy of upadacitinib and tofacitinib is particularly relevant in patients with severe disease, including acute severe ulcerative colitis, and upadacitinib maintains high efficacy regardless of prior advanced therapy exposure. JAK inhibitors also benefit extraintestinal manifestations. Although risks such as herpes zoster, serious infection, thromboembolism, and major cardiovascular events differ among agents, long-term data suggest generally acceptable safety when used appropriately. Intraclass JAK-to-JAK cycling is feasible, with about half of patients achieving steroid-free clinical remission in retrospective cohorts. Based on mechanistic, clinical, and real-world evidence, filgotinib may be a first-line option for patients with lower disease activity or when safety is a priority, whereas upadacitinib or tofacitinib may be preferred in higher disease activity. Strategically selecting agents may improve durability and outcomes.
10.Artificial intelligence-based personalized oncological outcome prediction model for upper urinary tract urothelial carcinoma after radical nephroureterectomy: A development and multicenter validation
Hyun Young LEE ; Hwanik KIM ; Bumjin LIM ; Dalsan YOU ; Cheryn SONG ; In Gab JEONG ; Jun Hyuk HONG ; Bumsik HONG ; Hanjong AHN ; Seung-hwan JEONG ; Ja Hyeon KU ; Jungyo SUH
Investigative and Clinical Urology 2026;67(1):15-23
Purpose:
To develop and validate an artificial intelligence (AI)-based personalized outcome prediction model for upper-urinary tract urothelial carcinoma patients undergoing radical nephroureterectomy.
Materials and Methods:
Data from patients who underwent radical nephroureterectomy between 2010 and 2020 across three hospitals were retrospectively analyzed. A model was developed using one tertiary center’s data and externally validated with data from two other hospitals. An AI model using XGBoost as risk estimator and bootstrapped Weibull Accelerated Failure Time model for 10-year survival probability was employed. Hyperparameter tuning used Optuna method. Model efficacy was assessed using concordance index, average Brier score, D-calibration, and six-month interval time-dependent area under the curve (AUC).
Results:
Of 1,039 patients, 627 qualified after excluding 50 with neoadjuvant chemotherapy. Model development used 564 patients (507 training, 57 test) with 9:1 stratified random split, plus 63 for internal validation and 362 for external validation. Significant parameters included preoperative glomerular filtration rate (p<0.001), hydroureteronephrosis (p=0.013), pathological N stage (p<0.001), concurrent carcinoma in situ (p<0.001), disease progression (p<0.001), and survival rate (p<0.001). Disease-free survival (DFS) model’s concordance index: internal validation 0.789, external validations 0.734 and 0.771. Overall survival (OS) model’s concordance index: internal validation 0.819, external validations 0.780 and 0.771. Mean time-dependent AUC was 0.66–0.77 for DFS and 0.67–0.80 for OS during 10-year periods.
Conclusions
AI-based model effectively predicts disease-free and OS outcomes for upper-urinary tract urothelial carcinoma patients with post-radical nephroureterectomy, showcasing robust performance across multicenter settings.

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