Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Background/Aims: The proposed eosinophilic esophagitis (EoE) endoscopic reference score serves to diagnose and evaluate treatment responses in EoE.Nevertheless, the validated reference score thresholds for diagnosis and treatment response in Asian patients are yet to be established.This study aims to establish these thresholds for the first time among Asian patients with EoE. Methods: Patients presenting with ≥ 15 eosinophils/high power field and esophageal dysfunction symptoms between August 2007 andNovember 2021 were included. Age- and sex-matched non-EoE controls were also enrolled. Baseline characteristics, endoscopic reference score features, and scores were compared between patients and controls. Among patients, endoscopic reference score features and scores, along with peak eosinophil counts, were evaluated both before and after treatment. The optimal threshold was determined based on sensitivity, specificity, and the Youden index. Results: Overall, 102 patients were enrolled (74.5% men; mean age, 46.9 years). The mean endoscopic reference score was 2.65 and 0.52 for patients and controls, respectively (P < 0.001). An endoscopic reference score ≥ 2 was identified as the optimal diagnostic threshold for EoE (sensitivity, 0.79; specificity, 0.86; Youden index, 0.66). Post-treatment data regarding endoscopic findings and histology wereavailable for 30 patients. Regarding histologic response, an endoscopic reference score of ≤ 3 demonstrated the optimal threshold(sensitivity, 0.95; specificity, 0.88; Youden index, 0.83). Conclusions The optimal diagnostic and treatment response thresholds were determined to be endoscopic reference scores of ≥ 2 and ≤ 3,respectively. Further studies involving a larger patient cohort are necessary to validate these findings.

Background/Aims: The proposed eosinophilic esophagitis (EoE) endoscopic reference score serves to diagnose and evaluate treatment responses in EoE.Nevertheless, the validated reference score thresholds for diagnosis and treatment response in Asian patients are yet to be established.This study aims to establish these thresholds for the first time among Asian patients with EoE. Methods: Patients presenting with ≥ 15 eosinophils/high power field and esophageal dysfunction symptoms between August 2007 andNovember 2021 were included. Age- and sex-matched non-EoE controls were also enrolled. Baseline characteristics, endoscopic reference score features, and scores were compared between patients and controls. Among patients, endoscopic reference score features and scores, along with peak eosinophil counts, were evaluated both before and after treatment. The optimal threshold was determined based on sensitivity, specificity, and the Youden index. Results: Overall, 102 patients were enrolled (74.5% men; mean age, 46.9 years). The mean endoscopic reference score was 2.65 and 0.52 for patients and controls, respectively (P < 0.001). An endoscopic reference score ≥ 2 was identified as the optimal diagnostic threshold for EoE (sensitivity, 0.79; specificity, 0.86; Youden index, 0.66). Post-treatment data regarding endoscopic findings and histology wereavailable for 30 patients. Regarding histologic response, an endoscopic reference score of ≤ 3 demonstrated the optimal threshold(sensitivity, 0.95; specificity, 0.88; Youden index, 0.83). Conclusions The optimal diagnostic and treatment response thresholds were determined to be endoscopic reference scores of ≥ 2 and ≤ 3,respectively. Further studies involving a larger patient cohort are necessary to validate these findings.

Purpose: Glycated hemoglobin (HbA1c) as a glycemic index may have limited value in pediatric patients with acute leukemia as they often present with anemia and/or pancytopenia. To address this issue, we evaluated the usefulness of glycated albumin (GA) as a glycemic monitoring index in pediatric patients with acute leukemia. Methods: Medical records of 25 patients with type 2 diabetes mellitus (T2DM), 63 patients with acute leukemia, and 115 healthy children from Seoul St. Mary's Hospital, The Catholic University of Korea, were retrospectively investigated for serum GA, HbA1c, and fasting blood glucose (FBG) levels, along with demographic data. Results: GA, HbA1c, and FBG levels did not differ between the control and acute leukemia groups. In the T2DM group, positive correlations were observed among GA, HbA1c, and FBG (P<0.01). Although GA level was not associated with the HbA1c level in the control group, GA and HbA1c levels showed a positive correlation in the acute leukemia group (P=0.045). Regression analysis revealed GA and HbA1c levels to be positively correlated in the acute leukemia and T2DM groups even after adjusting for age, sex, and body mass index z-score (P=0.007, P<0.01). Conclusion GA may be a useful complementary parameter to HbA1c for glycemic monitoring in pediatric patients with acute leukemia, similar to its use in patients with T2DM.

Purpose: The female sex is reported to have a higher risk of adverse events (AEs) from cytotoxic chemotherapy. Few studies examined the sex differences in AEs and their impact on the use of medical services during adjuvant chemotherapy. This sub-study aimed to compare the incidence of any grade and grade ≥ 3 AEs, healthcare utilization, chemotherapy completion rate, and dose intensity according to sex. Materials and Methods: This is a sub-study of a multicenter cohort conducted in Korea that evaluated the impact of healthcare reimbursement on AE evaluation in patients who received adjuvant chemotherapy between September 2013 and December 2016 at four hospitals in Korea. Results: A total of 1,170 patients with colorectal, gastric, or non–small cell lung cancer were included in the study. Female patients were younger, had fewer comorbidities, and experienced less postoperative weight loss of > 10%. Females had significantly higher rates of any grade AEs including nausea, abdominal pain, stomatitis, vomiting, and neutropenia, and experienced more grade ≥ 3 neutropenia, nausea, and vomiting. The dose intensity of chemotherapy was significantly lower in females, and they also experienced more frequent dose reduction after the first cycle. Moreover, female patients receiving platinum-containing regimens had significantly higher rates of unscheduled outpatient visits. Conclusion Our study found that females experienced a higher incidence of multiple any-grade AEs and severe neutropenia, nausea, and vomiting, across various cancer types, leading to more frequent dose reductions. Physicians should be aware of sex differences in AEs for chemotherapy decisions.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

Background: and Purpose Patients with cluster headache (CH) exhibit impaired health-related quality of life (HRQoL). However, there have been few studies related to the HRQoL of patients with CH from Asian backgrounds. This study aimed to determine the impact of CH on HRQoL and to identify the factors affecting HRQoL in patients with CH during cluster periods. Methods: This prospective study enrolled patients with CH from 17 headache clinics in South Korea between September 2016 and February 2021. The study aimed to determine HRQoL in patients with CH using the EuroQol 5 Dimensions (EQ-5D) index and the time trade-off (TTO) method. Age- and sex-matched headache-free participants were recruited as a control group. Results: The study included 423 patients with CH who experienced a cluster period at the time. EQ-5D scores were lower in patients with CH (0.88±0.43, mean±standard deviation) than in the controls (0.99±0.33, p<0.001). The TTO method indicated that 58 (13.6%) patients with CH exhibited moderate-to-severe HRQoL deterioration. The HRQoL states in patients with CH were associated with current smoking patterns, headache severity, frequency, and duration, and scores on the Generalized Anxiety Disorder 7-item scale (GAD-7), Patient Health Questionnaire 9-item scale (PHQ-9), 6-item Headache Impact Test, and 12-item Allodynia Symptom Checklist. Multivariable logistic regression analyses demonstrated that the HRQoL states in patients with CH were negatively correlated with the daily frequency of headaches, cluster period duration, and GAD-7 and PHQ-9 scores. Conclusions Patients with CH experienced a worse quality of life during cluster periods compared with the headache-free controls, but the degree of HRQoL deterioration varied among them. The daily frequency of headaches, cluster period duration, anxiety, and depression were factors associated with HRQoL deterioration severity in patients with CH.

Background/Aims: The proposed eosinophilic esophagitis (EoE) endoscopic reference score serves to diagnose and evaluate treatment responses in EoE.Nevertheless, the validated reference score thresholds for diagnosis and treatment response in Asian patients are yet to be established.This study aims to establish these thresholds for the first time among Asian patients with EoE. Methods: Patients presenting with ≥ 15 eosinophils/high power field and esophageal dysfunction symptoms between August 2007 andNovember 2021 were included. Age- and sex-matched non-EoE controls were also enrolled. Baseline characteristics, endoscopic reference score features, and scores were compared between patients and controls. Among patients, endoscopic reference score features and scores, along with peak eosinophil counts, were evaluated both before and after treatment. The optimal threshold was determined based on sensitivity, specificity, and the Youden index. Results: Overall, 102 patients were enrolled (74.5% men; mean age, 46.9 years). The mean endoscopic reference score was 2.65 and 0.52 for patients and controls, respectively (P < 0.001). An endoscopic reference score ≥ 2 was identified as the optimal diagnostic threshold for EoE (sensitivity, 0.79; specificity, 0.86; Youden index, 0.66). Post-treatment data regarding endoscopic findings and histology wereavailable for 30 patients. Regarding histologic response, an endoscopic reference score of ≤ 3 demonstrated the optimal threshold(sensitivity, 0.95; specificity, 0.88; Youden index, 0.83). Conclusions The optimal diagnostic and treatment response thresholds were determined to be endoscopic reference scores of ≥ 2 and ≤ 3,respectively. Further studies involving a larger patient cohort are necessary to validate these findings.

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.

Purpose: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. Methods: This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. Results: In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. Conclusions Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)