Background: and Purpose The National Brain Biobank of Korea (NBBK) is a brain bank consortium supported by the Korea Disease Control and Prevention Agency and the Korea National Institute of Health, and was launched in 2015 to support research into neurodegenerative disease dementia (NDD). This study aimed to introduce the NBBK and describes clinicopathological correlations based on analyses of data collected from the NBBK. Methods: Four hospital-based brain banks have been established in South Korea: Samsung Medical Center Brain Bank (SMCBB), Seoul National University Hospital Brain Bank (SNUHBB), Pusan National University Hospital Brain Bank (PNUHBB), and Myongji Hospital Brain Bank (MJHBB). Clinical and pathological data were collected from these brain banks using standardized protocols. The prevalence rates of clinical and pathological diagnoses were analyzed in order to characterize the clinicopathological correlations. Results: Between August 2016 and December 2023, 185 brain specimens were collected and pathologically evaluated (SNUHBB: 117; PNUHBB: 27; SMCBB: 34; MJHBB: 7). The age at consent was 70.8±12.6 years, and the age at autopsy was 71.7±12.4 years. The four-most-common clinical diagnoses were Alzheimer’s disease (AD) dementia (20.0%), idiopathic Parkinson’s disease (15.1%), unspecified dementia (11.9%), and cognitively unimpaired (CU) (11.4%).Most cases of unspecified dementia had a pathological diagnosis of central nervous system (CNS) vasculopathy (31.8%) or AD (31.8%). Remarkably, only 14.2% of CU cases had normal pathological findings. The three-most-common pathological diagnoses were AD (26.5%), CNS vasculopathy (14.1%), and Lewy body disease (13.5%). Conclusions These clinical and neuropathological findings provide a deeper understanding of the mechanisms underlying NDD in South Korea.

Background: and Purpose We aimed to determine the proportion of Korean patients with early Alzheimer’s disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment. Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study. Results: When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22. Conclusions Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.

Purpose: Physical activity (PA) is considered a potentially effective factor in the primary prevention of gastric cancer (GC). As body mass index (BMI) and waist circumference (WC) differ by sex, particularly with age, this study aimed to investigate the impact of PA on GC development, considering BMI and WC variations by sex. Materials and Methods: We analyzed the impact of PA on GC development using Cox proportional hazard regression in a cohort of 314,525 Korean individuals from the National Health Insurance Service–Health Screening database, using data from 2009–2019.Additionally, subgroup analyses were conducted based on BMI and WC. The models were adjusted for age, sex, smoking status, alcohol consumption, BMI, and comorbidities. Results: The effect of PA on the prevention of GC development was relatively evident in males. The high PA group (metabolic equivalents of task, METs/week of 500–999) showed a lower risk of GC compared to the group with METs/week of 0 (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.79–0.98). Especially in males with WC <90 cm and BMI <23 kg/m2 , a lower risk of GC was observed in the group with METs/week of 1–499 compared to the group with METs/week of 0 (HR, 0.80; 95% CI, 0.67–0.96). In contrast, no consistent association was observed between PA levels and risk of GC in females. Conclusions Moderate PA had a preventive effect on GC development in males, particularly in those with low BMI and WC. However, this effect was not observed in females.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Objectives: To propose age group classification criteria for efficient tooth loss management by ana-lyzing the distribution of tooth loss in Korean adults by age group and causes of tooth loss. In addi-tion, to determine the efficacy of a Significant Tooth Loss index. Methods: The study included 13,199 adults who participated in the seventh Korea National Health and Nutrition Examination Survey (2016-2018). The mean number of missing teeth was compared by classifying the ages into 10- and 5-year intervals. Based on this analysis, the distribution of missing teeth was determined by classifying the age groups into 15-year intervals. Subsequently, the causes of tooth loss by age group at 15-year intervals and the efficacy of the Significant Tooth Loss Index were determined. Results: Classification at 5-year age intervals was more appropriate for analyzing changes in the distribution of missing teeth than classification at 10-year age intervals. However, establishing a public oral health program for the management of tooth loss on a 5-year or 10-year basis is im-practical. Therefore, a classification method with 15-year age intervals was proposed, in which the groups were young (19-34 years), middle-aged (35-49 years), older adult (50-64 years), and elderly (65 years or older). Although the criteria for the Significant Tooth Loss Index were appropri-ate for the young, older adults, and elderly groups, modifications were required for the middle-aged group. Conclusions Age-based oral health programs for adults should be promoted to prevent tooth loss by classifying adults into different age groups based on their clinical characteristics.

Purpose: To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression Methods: A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated. Results: Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis. Conclusions A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.

Purpose: To investigate the outcomes of brolucizumab reinjection after intraocular inflammation (IOI) development. Methods: This retrospective study analyzed patients with brolucizumab injections from April 2021 to January 2024. Patients who developed IOI after brolucizumab were included and categorized into subgroups depending on reinjection, discontinuation, and further IOI development. Results: A total of 472 eyes of 432 patients received brolucizumab injections. Thirty-eight cases developed IOI at least once, and 25 continued brolucizumab. Sixteen cases had no more IOI events, and nine experienced a second or more IOI events. Among the nine cases, three maintained brolucizumab injections despite IOI recurrence. The incidence of IOI was 8.1% based on the number of eyes (38 of 472 eyes) and 2.0% based on the number of brolucizumab injections (50 of 2,468 injections). The incidence of occlusive retinal vasculitis was 0.2% (1 of 472 eyes). The recurrence rate was 23.7% (9 of 38 eyes). The average number of injections between the first brolucizumab injection and the injection date on which IOI first developed was 2.15 times in the no-reinjection group, 3.44 times in the no-IOI-recurrence group, and 2.0 times in the second-IOI-episode group. Time to IOI occurrence in cases with first IOI episode was 18.60 ± 16.73 days, with 15 cases developing IOI within 1 week. Conclusions This study elucidates the real-world incidence of brolucizumab associated IOIs, with a description of information related to reinjections after the IOI episodes. A comprehensive understanding of brolucizumab reinjection is essential for its optimal utilization.