Background: This study analyzed the epidemiology and treatment outcomes of germ cell tumorpatients at a single institution. Methods: A retrospective analysis was conducted on intracranial germ cell tumor (iGCT) pa-tients treated at a single tertiary hospital from 2004 to 2019. Patients were categorized based on treatment modality: Korean Society for Pediatric Neuro-Oncology (KSPNO) protocol or bleomycin, etoposide, and cisplatin with radiation therapy. Results: Forty-nine iGCT patients treated with combined chemotherapy and radiotherapywere analyzed. The median age was 19 years (range: 6–40), with a median follow-up duration of 148.0 months (range: 10.5–265.5). Tumors were most common in the pineal gland (51.0%). Although no significant differences in outcomes were observed between treatment modalities, outcomes varied significantly by pathological type. The 10-year progression-free survival rates for germinoma and non-germinomatous germ cell tumors (NGGCTs) were 88.1% and 32.7%, respectively (p=0.003), while the 10-year overall survival rates were 92.9% and 67.5%, respectively (p<0.001). Fourteen patients experienced CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 adverse events, with one eventrelated death. Conclusion Pure germinoma demonstrated higher survival and lower recurrence rates comparedto NGGCT. The KSPNO protocol appears to be an acceptable and safe treatment option for iGCT patients. Further multi-institutional studies with larger cohorts are warranted.

Purpose: Considering the high disease burden and unique features of Asian patients with breast cancer (BC), it is essential to have a comprehensive view of genetic characteristics in this population. An institutional targeted sequencing platform was developed through the Korea Research-Driven Hospitals project and was incorporated into clinical practice. This study explores the use of targeted next-generation sequencing (NGS) and its outcomes in patients with advanced/metastatic BC in the real world. Materials and Methods: We reviewed the results of NGS tests administered to BC patients using a customized sequencing platform—FiRST Cancer Panel (FCP)—over 7 years. We systematically described clinical translation of FCP for precise diagnostics, personalized therapeutic strategies, and unraveling disease pathogenesis. Results: NGS tests were conducted on 548 samples from 522 patients with BC. Ninety-seven point six percentage of tested samples harbored at least one pathogenic alteration. The common alterations included mutations in TP53 (56.2%), PIK3CA (31.2%), GATA3 (13.8%), BRCA2 (10.2%), and amplifications of CCND1 (10.8%), FGF19 (10.0%), and ERBB2 (9.5%). NGS analysis of ERBB2 amplification correlated well with human epidermal growth factor receptor 2 immunohistochemistry and in situ hybridization. RNA panel analyses found potentially actionable and prognostic fusion genes. FCP effectively screened for potentially germline pathogenic/likely pathogenic mutation. Ten point three percent of BC patients received matched therapy guided by NGS, resulting in a significant overall survival advantage (p=0.022), especially for metastatic BCs. Conclusion Clinical NGS provided multifaceted benefits, deepening our understanding of the disease, improving diagnostic precision, and paving the way for targeted therapies. The concrete advantages of FCP highlight the importance of multi-gene testing for BC, especially for metastatic conditions.

The common data model (CDM) has found widespread application in healthcare studies, but its utilization in cancer research has been limited. This article describes the development and implementation strategy for Cancer Clinical Library Databases (CCLDs), which are standardized cancer-specific databases established under the Korea-Clinical Data Utilization Network for Research Excellence (K-CURE) project by the Korean Ministry of Health and Welfare. Fifteen leading hospitals and fourteen academic associations in Korea are engaged in constructing CCLDs for 10 primary cancer types. For each cancer type-specific CCLD, cancer data experts determine key clinical data items essential for cancer research, standardize these items across cancer types, and create a standardized schema. Comprehensive clinical records covering diagnosis, treatment, and outcomes, with annual updates, are collected for each cancer patient in the target population, and quality control is based on six-sigma standards. To protect patient privacy, CCLDs follow stringent data security guidelines by pseudonymizing personal identification information and operating within a closed analysis environment. Researchers can apply for access to CCLD data through the K-CURE portal, which is subject to Institutional Review Board and Data Review Board approval. The CCLD is considered a pioneering standardized cancer-specific database, significantly representing Korea’s cancer data. It is expected to overcome limitations of previous CDMs and provide a valuable resource for multicenter cancer research in Korea.

Background/Aims: This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV). Methods: Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified. Results: Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05). Conclusions This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.

Background and Objectives: Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years. Results: There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults. Conclusion The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.

Background and Objectives: This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss. Results: The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults. Conclusion The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.

It is difficult to determine a cause of bile duct stricture and dilatation. Eosinophilic cholangitis, a rare benign condition, may be one cause of bile duct stricture and dilatation. It can be evaluated using various methods of histopathology, radiographs, endoscopy, and hematologic findings. Treatment generally involves steroid therapy which can lead to improvement. This case report will discuss eosinophilic cholangitis, emphasizing that while it can easily be overlooked but should be considered in differential diagnoses.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Background/Aims: Krebs von den Lungen-6 (KL-6) is associated with prognosis in patients with COVID-19. However, there is limited data on the correlation between the prognosis of COVID-19 and varying KL-6 levels at different time points. We investigated the optimal cutoff values of the initial and peak serum KL-6 levels to predict mortality and evaluated their correlation with mortality. Methods: This retrospective cohort study collected data on serially collected serum KL-6 levels in patients hospitalized with COVID-19 between October 2020 and January 2022 at a single tertiary hospital in South Korea. The area under the receiver operating characteristic curve and Youden index were used to determine the cutoff points for the initial and peak KL-6 levels that best predicted 30-day mortality. The association between the initial and peak KL-6 values was assessed by univariate and multivariate logistic regression models. Results: A total of 349 patients were included in this study. The mean initial and peak KL-6 levels were significantly higher in the non-survivor group than in the survivor group. The initial and peak KL-6 values that best predicted 30-day mortality were 491.85 U/mL and 660.05 U/mL, respectively. An initial KL-6 level greater than 491.85 U/mL and a peak KL-6 level greater than 660.05 U/mL were significantly associated with 30-day mortality. Conclusions The initial and peak levels of KL-6 were significantly associated with 30-day mortality in hospitalized patients with COVID-19. These findings suggest that serially monitoring blood KL-6 levels could be a valuable prognostic indicator for COVID-19.