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.

Purpose: Although bladder cancer occurs three to 4 times more frequently in men than in women, the relative number of deaths compared to incidence is higher in women, suggesting that women have a worse prognosis than men. Emerging evidence indicates that the activity of the sex steroid hormone pathway may play a role in bladder cancer development, with demonstrations that both androgens and estrogens have biological effects on bladder cancer in vitro and in vivo. This study investigates the influence of sex and menopausal status on recurrence and cancer-specific death (CSD) in bladder cancer patients undergoing radical cystectomy (RC). Materials and Methods: This retrospective analysis included 3,913 patients from the Korean Bladder Cancer Study Group Database who underwent RC between 2010 and 2019. Patients were categorized based on gender and menopausal status (≤50 years: premenopausal; >50 years: postmenopausal). Pathological factors, neoadjuvant chemotherapy, recurrence, and CSD rates were analyzed using chi-square and Fisher exact tests. Results: Among the 3,913 patients, 400 (10.2%) were female. Premenopausal females exhibited significantly lower recurrence rates (28.6%) compared to postmenopausal females (45.7%). CSD rates were similarly reduced in premenopausal females (12.0% vs. 22.2% in postmenopausal females). No significant sex differences in recurrence or CSD were observed among premenopausal patients. Pathological T stage, nodal status, and lymphovascular invasion were significantly associated with recurrence in males, while nodal status alone was significant in females. Neoadjuvant chemotherapy was significantly more frequently administered to male patients under the age of 50, while no difference was observed in the administration of neoadjuvant chemotherapy among female patients based on menopausal status. Conclusion Hormonal changes associated with menopause significantly influence bladder cancer outcomes in women. Premenopausal hormonal environments seem protective, underscoring the need for further research into hormone-driven mechanisms in bladder cancer.

Purpose: To evaluate whether extended pelvic lymph node dissection (PLND) improves survival outcomes compared with standard PLND in patients with bladder cancer (BCa) undergoing radical cystectomy (RC), and to assess its potential benefits in patients with prior or concurrent radical nephroureterectomy (p/cRNU). Materials and Methods: A multicenter analysis included 2202 patients with BCa undergoing RC with standard or extended PLND at 11 tertiary centers from 2003 to 2023. Following propensity score matching, 659 pairs (n=1,318), including 128 patients with p/cRNU, were analyzed. Recurrence-free survival (RFS) was the primary outcome, while overall survival (OS), cancer-specific survival (CSS), and readmission rates were secondary outcomes. Survival analyses performed using Kaplan-Meier methods and clustered Cox models. Results: Extended PLND yielded significantly more lymph nodes than standard PLND (median: 27.0 vs. 17.0, p<0.001) but did not improve RFS, CSS, or OS in the overall cohort (all p>0.05). Extended PLND increased readmission rates (28.4% vs. 20.2%, p=0.001) and readmission risk (odds ratio, 1.57; 95% confidence interval [CI], 1.15–2.16, p=0.005). However, subgroup analysis revealed extended PLND significantly improved RFS in patients with p/cRNU (hazard ratio, 0.54; 95% CI, 0.38–0.77; p<0.001). Conclusion Extended PLND does not provide survival benefits for overall patient population and increases readmission risk but significantly improves RFS in patients with p/cRNU. Tailoring PLND extent based on upper tract disease status is recommended.

Purpose: This study aimed to evaluate the prognostic value of a trifecta, defined as negative soft tissue surgical margin (STSM), removal of ≥16 lymph nodes, and absence of major complications (Clavien-Dindo classification grade >III) within 90 days, after radical cystectomy (RC), using a large multicenter cohort. Materials and Methods: We retrospectively analyzed data from 3,972 patients with bladder cancer who underwent RC at 11 tertiary centers in South Korea between 2003 and 2024. Survival outcomes, including overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS), were compared according to trifecta status using Kaplan-Meier and Cox regression analyses. Propensity score matching was performed to adjust for baseline differences. Results: A total of 2,014 eligible patients were included in the final analysis, and the trifecta was achieved in 47.8%. Kaplan-Meier analysis demonstrated significantly improved 5- and 10-year OS (66.7% vs. 62.0%; 62.9% vs. 57.2%; p=0.002), CSS (79.3% vs. 75.4%; 77.8% vs. 73.8%; p=0.008), and RFS (62.7% vs. 57.6%; 60.8% vs. 55.2%; p=0.001) in the trifecta group. In multivariable analysis, trifecta achievement was significantly associated with better OS (HR, 0.813; p=0.008), CSS (HR, 0.787; p=0.017), and RFS (HR, 0.844; p=0.036). Among individual components, negative STSM showed the strongest prognostic effect across all endpoints. Conclusions In this large multicenter study, patients who achieved the RC trifecta exhibited significantly superior survival outcomes compared with those who did not. The trifecta may serve as a practical and standardized metric for assessing surgical quality and performance in RC. Future prospective studies are warranted to validate its prognostic and quality-assurance utility.

Background/Aims: Intragastric balloon (IGB) is the only available endoscopic bariatric and metabolic therapy in Korea. End-ball (Endalis) has the longest history of clinical use among the IGBs available in Korea. However, little clinical data on this system have been reported. In this study, we aimed to evaluate the efficacy and safety of End-ball in Korea. Methods: We performed a retrospective cohort study of patients who underwent IGB insertion (End-ball) from 2013 to 2019. Demographic and anthropometric data were collected. The efficacy and safety of IGB treatment were analyzed. Results: In total, 80 patients were included. Mean age was 33.7 years and 83.8% were female. Initial body mass index was 34.48±4.69 kg/m2. Body mass index reduction was 3.72±2.63 kg/m2 at the time of IGB removal. Percent of total body weight loss (%TBWL) was 10.76%±6.76%. Percentage excess body weight loss was 43.67%±27.59%. Most adverse events were minor, and 71.4% of participants showed nausea, vomiting, or abdominal pain. Conclusions IGB treatment showed good efficacy and safety profile in Korean patients with obesity. In terms of %TBWL and percentage excess body weight loss, the efficacy was similar to that in the Western population.

Background: The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). Methods: A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. Results: A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P < 0.001), while trend toward an increase in the relative proportion of S. aureus (rs = 0.850, P < 0.001), S. agalactiae (rs = 0.615, P = 0.001), and S. pyogenes (rs = 0.554, P = 0.005). Conclusion In the proportion of IBIs over a 24-year period between 1996 and 2019, we observed a decreasing trend for S. pneumoniae and H. influenzae and an increasing trend for S. aureus, S. agalactiae, and S. pyogenes in children > 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.

Tolvaptan reduces height-adjusted total kidney volume (htTKV) and renal function decline in autosomal dominant polycystic kidney disease (ADPKD). This study was aimed at investigating the efficacy and safety of tolvaptan in Korean patients with ADPKD during the titration period. Methods: This study is a multicenter, single-arm, open-label phase 4 study. We enrolled 108 patients with ADPKD (age, 19–50 years) with an estimated glomerular filtration rate (eGFR) of >30 mL/min/1.73 m2 and factors defined as indicative of rapid disease progression. After tolvaptan titration, we evaluated efficacy and side effects and assessed factors associated with the effects. Results: After titration for 4 weeks, eGFR and htTKV decreased by 6.4 ± 7.9 mL/min/1.73 m2 and 16 ± 45 mL/m, respectively. No serious adverse drug reactions were observed during the titration period. The greatest eGFR decline was observed in the first week, with a starting tolvaptan dose of 45 mg. Multivariate linear regression for htTKV decline showed that the greater the change in urine osmolality (Uosm), the greater the decrease in htTKV (β, 0.436; p = 0.009) in the 1D group stratified by the Mayo Clinic image classification. Higher baseline eGFR was related to a higher htTKV reduction rate in the 1E group (β, –0.642; p = 0.009). Conclusion: We observed short-term effects and safety during the tolvaptan titration period. The decline of htTKV can be predicted as a short-term effect of tolvaptan by observing Uosm changes from baseline to end of titration in 1D and baseline eGFR in 1E groups.

Objective: Influenza is an acute, respiratory viral disease, and may lead to complications such as pneumonia, which presents with significant morbidity and mortality. Previous studies did not have sufficient data regarding the risk factors and complications of the H1N1 flu caused by the influenza A virus subtype H1N1 during the 2009 pandemic in Korea. Therefore, this study was conducted to analyze the characteristics and risk factors of complicated influenza. Methods: Data were collected from influenza patients who visited a local emergency center in Daegu from January 2017 to December 2019. The study population was divided into three groups: influenza, influenza pneumonia, and influenza with a bacterial infection. The patients’ sex, age, influenza type, comorbidities, vital signs, symptoms, laboratory findings, and clinical outcomes were investigated for the risk analysis of complicated influenza. Results: The total number of patients was 574, of which 393 (68.5%) had influenza only, 135 (23.5%) had influenza pneumonia, and 46 (8%) had influenza with a bacterial infection. The odds ratio of complicated influenza was found using multivariate logistic regression analysis; for influenza pneumonia, it was 2.94 for patients aged over 65-years, 3.47 for those with an elevated procalcitonin level, 2.24 for cough, 6.41 for dyspnea, and 3.11 for renal disease. For influenza with bacterial infection, the odds ratio was 2.31 for males, 2.68 for over 80-year-olds, 3.75 for elevated procalcitonin levels, 7.61 for dyspnea, and 3.65 for nursing home residents. Conclusion The risk factors of complicated influenza were advanced age, elevated procalcitonin level, dyspnea, renal disease, and residing in a nursing home.

Background/Aims: Hypertension (HT) has a significant impact on public health and medical expenses. However, HT is a chronic disease that requires the long-term follow-up of a large number of patients. Methods: The Korean Hypertension Cohort (KHC) study aimed to develop a model for calculating cardiovascular risk in HT patients by linking and utilizing the detailed clinical and longitudinal data from hospitals and the national health insurance claim database, respectively. This cohort had a planned sample size of over 11,000 HT patients and 100,000 non-HT controls. Eligible patients were hypertensive patients, who were presenting for the first time and were diagnosed with HT as a main disease from 2006 to 2011. Long-term survival data over a period of approximately 9 years were obtained from the national health insurance claim and national health examination data. Results: This cohort enrolled 11,083 patients with HT. The mean age was 58.87 ± 11.5 years, 50.5% were male, and 31.4% were never-treated HT. Of the enrolled patients, 32.9% and 37.7% belonged to the high and moderate cardiovascular risk groups, respectively. Initial blood pressures were 149.4 ± 18.5/88.5 ± 12.5 mmHg. During the 2 years hospital data follow-up period, blood pressures lowered to 130.8 ± 14.1/78.0 ± 9.7 mmHg with 1.9 ± 1.0 tablet doses of antihypertensive medication. Cardiovascular events occurred in 7.5% of the overall patients; 8.5%, 8.8%, and 4.7% in the high, moderate, and low risk patients, respectively. Conclusions The KHC study has provided important information on the long-term outcomes of HT patients according to the blood pressure, comorbid diseases, medication, and adherence, as well as health behaviors and health resource use.