Korean Association Research Articles

Safety of cold snare resection techniques for removal of small colon polyps in patients with clopidogrel and aspirin: A Korean Association for the Study of Intestinal Diseases prospective, multicenter study

/Aims: Polypectomy is a procedure associated with a high risk of bleeding. Guidelines recommend uninterrupted aspirin use during polypectomy, whereas cessation of clopidogrel 5-7 days before polypectomy is recommended. The cold snare resection technique, with or without submucosal injection, is considered safer than conventional polypectomy using electrocoagulation for post-polypectomy bleeding. In this study, we aimed to compare the bleeding complications associated with cold snare resection between clopidogrel and aspirin users. This multicenter, prospective cohort study was conducted in five academic hospitals in Korea and included clopidogrel and aspirin users who underwent polypectomy. Antiplatelet agents were used without interruption, with ≤ 3 days of interruption defined as continuous use. The primary endpoint was delayed bleeding, which was defined as bleeding occurring several hours after polypectomy, whereas immediate bleeding was defined as bleeding requiring hemostasis 2 min after polypectomy. Risk factors for immediate bleeding were investigated for each polyp. Among the 263 patients (clopidogrel, n = 129; aspirin, n = 134), 509 underwent polypectomies. The rate of delayed bleeding per patient in the clopidogrel and aspirin groups was 0.8% and 0.7%, respectively, meeting noninferiority (rate difference 0.03% [95% confidence interval: -2.07% to 2.13%]). Hemostasis was achieved in 100 patients who underwent polypectomy (19.8%). Immediate bleeding risk factors included female sex, end-stage renal disease, submucosal injection before resection, and polyp size ≥ 5 mm. This multicenter prospective study demonstrated the safety of cold snare resection in patients treated with uninterrupted clopidogrel and aspirin (NCT04328987).

Report of the Korean Association of External Quality Assessment Service on Next-Generation Sequencing-Based Liquid Biopsy (2020–2023)

Report of the Korean Association of External Quality Assessment Service on Next-Generation Sequencing-Based Liquid Biopsy (2020–2023)

Annual Report of the Korean Association of External Quality Assessment Service on General Chemistry (2023)

Annual Report of the Korean Association of External Quality Assessment Service on General Chemistry (2023)

Multipartite network analysis to identify environmental and genetic associations of metabolic syndrome in the Korean population

Network analysis has become a crucial tool in genetic research, enabling the exploration of associations between genes and diseases. Its utility extends beyond genetics to include the assessment of environmental factors. Unipartite network analysis is commonly used in genomics to visualize initial insights and relationships among variables. Syndromic diseases, such as metabolic syndrome, are characterized by the simultaneous occurrence of various signs, symptoms, and clinicopathological features. Metabolic syndrome encompasses hypertension, diabetes, obesity, and dyslipidemia, and both genetic and environmental factors contribute to its development. Given that relevant data often consist of distinct sets of variables, a more intuitive visualization method is needed. This study applied multipartite network analysis as an effective method to understand the associations among genetic, environmental, and disease components in syndromic diseases. We considered three distinct variable sets: genetic factors, environmental factors, and disease components. The process involved projecting a tripartite network onto a two-mode bipartite network and then simplifying it into a one-mode network. This approach facilitated the visualization of relationships among factors across different sets and within individual sets. To transition from multipartite to unipartite networks, we suggest both sequential and concurrent projection methods. Data from the Korean Association Resource (KARE) project were utilized, including 352,228 SNPs from 8840 individuals, alongside information on environmental factors such as lifestyle, dietary, and socioeconomic factors. The single-SNP analysis step filtered SNPs, supplemented by reference SNPs reported in a genome-wide association study catalog. The resulting network patterns differed significantly by sex: demographic factors and fat intake were crucial for women, while alcohol consumption was central for men. Indirect relationships were identified through projected bipartite networks, revealing that SNPs such as rs4244457, rs2156552, and rs10899345 had lifestyle interactions on metabolic components. Our approach offers several advantages: it simplifies the visualization of complex relationships among different datasets, identifies environmental interactions, and provides insights into SNP clusters sharing common environmental factors and metabolic components. This framework provides a comprehensive approach to elucidate the mechanisms underlying complex diseases like metabolic syndrome.

Impact of longitudinal tumor location on postoperative outcomes in gallbladder cancer: Fundus and body vs. neck and cystic duct, a retrospective multicenter study.

Systematic investigations into the prognostic impact of the longitudinal tumor location in gallbladder cancer (GBC) remain insufficient. To address the limitations of our pilot study, we conducted a multicenter investigation to clarify the impact of the longitudinal tumor location on the oncological outcomes of GBC. A retrospective multicenter study was conducted on 372 patients undergoing radical resections for GBC from January 2010 to December 2019 across seven hospitals that belong to the Daejeon-Chungcheong branch of the Korean Association of Hepato-Biliary-Pancreatic Surgery. Patients were divided into GBC in the fundus/body (FB-GBC) and GBC in the neck/cystic duct (NC-GBC) groups, based on the longitudinal tumor location. Of 372 patients, 282 had FB-GBC, while 90 had NC-GBC. NC-GBC was associated with more frequent elevation of preoperative carbohydrate antigen (CA) 19-9 levels, requirement for more extensive surgery, more advanced histologic grade and tumor stages, more frequent lymphovascular and perineural invasion, lower R0 resection rates, higher recurrence rates, and worse 5-year overall and disease-free survival rates. Propensity score matching analysis confirmed these findings, showing lower R0 resection rates, higher recurrence rates, and worse survival rates in the NC-GBC group. Multivariate analysis identified elevated preoperative CA 19-9 levels, lymph node metastasis, and non-R0 resection as independent prognostic factors, but not longitudinal tumor location. NC-GBC exhibits more frequent elevation of preoperative CA 19-9 levels, more advanced histologic grade and tumor stages, lower R0 resection rates, and poorer overall and disease-free survival rates, compared to FB-GBC. However, the longitudinal tumor location was not analyzed as an independent prognostic factor.

A comprehensive multi-task deep learning approach for predicting metabolic syndrome with genetic, nutritional, and clinical data

Metabolic syndrome (MetS) is a complex disorder characterized by a cluster of metabolic abnormalities, including abdominal obesity, hypertension, elevated triglycerides, reduced high-density lipoprotein cholesterol, and impaired glucose tolerance. It poses a significant public health concern, as individuals with MetS are at an increased risk of developing cardiovascular diseases and type 2 diabetes. Early and accurate identification of individuals at risk for MetS is essential. Various machine learning approaches have been employed to predict MetS, such as logistic regression, support vector machines, and several boosting techniques. However, these methods use MetS as a binary status and do not consider that MetS comprises five components. Therefore, a method that focuses on these characteristics of MetS is needed. In this study, we propose a multi-task deep learning model designed to predict MetS and its five components simultaneously. The benefit of multi-task learning is that it can manage multiple tasks with a single model, and learning related tasks may enhance the model's predictive performance. To assess the efficacy of our proposed method, we compared its performance with that of several single-task approaches, including logistic regression, support vector machine, CatBoost, LightGBM, XGBoost and one-dimensional convolutional neural network. For the construction of our multi-task deep learning model, we utilized data from the Korean Association Resource (KARE) project, which includes 352,228 single nucleotide polymorphisms (SNPs) from 7729 individuals. We also considered lifestyle, dietary, and socio-economic factors that affect chronic diseases, in addition to genomic data. By evaluating metrics such as accuracy, precision, F1-score, and the area under the receiver operating characteristic curve, we demonstrate that our multi-task learning model surpasses traditional single-task machine learning models in predicting MetS.

Koreanizing International Politics: Focusing on the early activities of Korean Association of International Studies(KAIS)

Koreanizing International Politics: Focusing on the early activities of Korean Association of International Studies(KAIS)

Carbohydrate Intake Levels and the Risk of Metabolic Syndrome in Korean Populations: A Prospective Study.

In Korea and other Asian countries, traditional high-carbohydrate diets are increasingly associated with metabolic syndrome (MetS) and its complications. As dietary patterns shift, there is a growing need to assess the effect of these changes on health outcomes related to MetS. This study aimed to investigate the prospective relationship between carbohydrate consumption and the risk of MetS and its components. We analyzed data from 7902 participants from the Korean Association Resource, part of the Korean Genome and Epidemiology Study Dietary intakes, including carbohydrates and fiber, were assessed using a validated semi-quantitative food frequency questionnaire, allowing for the calculation of the proportion of total energy from carbohydrates (P_CARB) and the carbohydrate-to-fiber ratio to assess carbohydrate quality. Blood samples were collected after at least eight hours of fasting for laboratory analysis. We employed Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals, focusing on the relationship between the P_CARB and the risk of developing MetS and its individual components, while adjusting for carbohydrate quality. In the fully adjusted model, which accounted for carbohydrate quality as a covariate, individuals in the highest percentile of the P_CARB showed a significantly increased risk of MetS, hypertriglyceridemia, hypo-high density lipoprotein cholesterolemia, dyslipidemia, and high blood pressure, compared to those in the lowest P_CARB group. Spline curve analyses indicated that the risks for MetS and its components consistently escalated with increasing P_CARB, with all p-values for nonlinearity exceeding 0.05. The findings suggest that higher levels of P_CARB are associated with an increased risk of MetS and related conditions, except for high fasting glucose. These results highlight the importance of dietary awareness and potential adjustments for populations consuming high-carbohydrate diets.

Factors Associated with Postoperative Recurrence in Stage I to IIIA Non-Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation: Analysis of Korean National Population Data.

Recent development in perioperative treatment of resectable non-small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection. Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee. A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors. Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.

Case Study on Analysing the Early Disease Detection of Pancreatic Ductal Adenocarcinoma in Korean Association for Clinical Oncology.

Pancreatic ductal adenocarcinoma (PDAC) is the most pervasive sort of pancreatic malignant growth. Due to the lack of early symptoms and effective methods for early detection and screening, the majority of patients (80% to 85%) are diagnosed with advanced metastatic or locally advanced disease, resulting in a low 5-year survival rate of 12%. The case study represents a comprehensive investigation into the intricate landscape of pancreatic cancer diagnosis within the Korean population. Grounded in epidemiological bits of knowledge, the review plans to disentangle the particular examples, commonness, and segment attributes of PDAC in Korea. By scrutinizing current diagnostic modalities, including conventional imaging techniques, molecular markers, and emerging technologies, the research seeks to evaluate the strengths and limitations of existing approaches within the Korean clinical context. Central to the study is an exploration of the collaborative initiatives spearheaded by the Association of Clinical Oncology in Korea in the domain of PDAC early detection. Analysing research projects, clinical trials, and interdisciplinary collaborations, the case study sheds light on the association's pivotal role in driving innovation and progress in oncology. The goal is to offer a detailed analysis of how the association helps in furthering knowledge and enhancing results in the management of PDAC. The case study delves into the implications of early PDAC detection for patient outcomes, emphasizing the significance of timely interventions and tailored treatment strategies. By outlining the potential benefits and challenges associated with early diagnosis, the study aims to inform health care policies, shape clinical guidelines, and guide future research priorities. Through a holistic approach, the case study endeavours to offer important experiences into the multifaceted landscape of PDAC early detection within the Korean health care system, contributing to the broader discourse on effective oncological practices and patient care.

Annual Report on the Results of Accuracy-Based Creatinine Proficiency Testing in Korea (2023) by the Korean Association of External Quality Assessment Service

Annual Report on the Results of Accuracy-Based Creatinine Proficiency Testing in Korea (2023) by the Korean Association of External Quality Assessment Service

한국 화교 공동체 조직의 변천과 특징

This paper systematically examines the evolution, characteristics, and role of Korean overseas Korean community organizations over the past hundred years. Korean overseas Chinese organizations have played an important role in the development and unity of the Korean overseas Chinese community, but there is a great lack of research on them. Therefore, through a survey on the social organizations of overseas Koreans, this book reveals the current status of trend organizations and overseas Korean associations and explores the process of organization formation in the Korean overseas Korean community. In particular, we analyzed the Seoul and Incheon areas, which are the economic centers of the Korean diaspora with the largest diaspora population today. By examining the formation and development of social organizations in Incheon and Seoul, which are the nucleus of the overseas Korean community, we explain the changes in the overseas Korean community since the establishment of diplomatic relations between China and Korea in terms of the government’s increased interest in and policies toward the overseas Korean community, the rapid development of private economic and trade relations between China and Korea, efforts to expand overseas exchanges, and the revival of the overseas Korean community. He also pointed out that the mutual migration of Chinese and Korean citizens will have an important impact on the future development of both countries.

Replication Study of Genome Wide Association Study of Sleep Duration in Korean Association Resources Cohort

Replication Study of Genome Wide Association Study of Sleep Duration in Korean Association Resources Cohort

Quantitative Evaluation of the Real-World Harmonization Status of Laboratory Test Items Using External Quality Assessment Data.

In recent decades, the analytical quality of clinical laboratory results has substantially increased because of collaborative efforts. To effectively utilize laboratory results in applications, such as machine learning through big data, understanding the level of harmonization for each test would be beneficial. We aimed to develop a quantitative harmonization index that reflects the harmonization status of real-world laboratory tests. We collected 2021-2022 external quality assessment (EQA) results for eight tests (HbA1c, creatinine, total cholesterol, HDL-cholesterol, triglyceride, alpha-fetoprotein [AFP], carcinoembryonic antigen [CEA], and prostate-specific antigen [PSA]). This EQA was conducted by the Korean Association of External Quality Assessment Service, using commutable materials. The total analytical error of each test was determined according to the bias% and CV% within peer groups. The values were divided by the total allowable error from biological variation (minimum, desirable, and optimal) to establish a real-world harmonization index (RWHI) at each level (minimum, desirable, and optimal). Good harmonization was arbitrarily defined as an RWHI value ≤ 1 for the three levels. Total cholesterol, triglyceride, and CEA had an optimal RWHI of ≤ 1, indicating an optimal harmonization level. Tests with a desirable harmonization level included HDL-cholesterol, AFP, and PSA. Creatinine had a minimum harmonization level, and HbA1c did not reach the minimum harmonization level. We developed a quantitative RWHI using regional EQA data. This index may help reflect the actual harmonization level of laboratory tests in the field.

Conversion surgery for initially unresectable locally advanced biliary tract cancer: A multicenter collaborative study conducted in Japan and Korea.

Although surgical resection is the only curative treatment for biliary tract cancer, in some cases, the disease is diagnosed as unresectable at initial presentation. There are few reports of conversion surgery after the initial treatment for unresectable locally advanced biliary tract cancer. This study aimed to evaluate the efficacy and safety of conversion surgery in patients with initially unresectable locally advanced biliary tract cancer. We retrospectively collected clinical data from groups of patients in multiple centers belonging to the Japanese Society of Hepato-Biliary-Pancreatic Surgery and Korean Association of Hepato-Biliary-Pancreatic Surgery. We analyzed two groups of prognostic factors (pretreatment and surgical factors) and their relation to the treatment outcomes. A total of 56 patients with initially unresectable locally advanced biliary tract cancer were enrolled in this study of which 55 (98.2%) patients received chemotherapy, and 16 (28.6%) patients received additional radiation therapy. The median time from the start of the initial treatment to resection was 6.4 months. Severe postoperative complications of Clavien-Dindo grade III or higher occurred in 34 patients (60.7%), and postoperative mortality occurred in five patients (8.9%). Postoperative histological results revealed CR in eight patients (14.3%). The median survival time from the start of the initial treatment in all 56 patients who underwent conversion surgery was 37.7 months, the 3-year survival rate was 53.9%, and the 5-year survival rate was 39.1%. Conversion surgery for initially unresectable locally advanced biliary tract cancer may lead to longer survival in selected patients. However, more precise preoperative safety evaluation and careful postoperative management are required.

Discordance Rate and Risk Factor of Other Diagnostic Modalities for Small Bowel Tumors Detected by Device-Assisted Enteroscopy: A Korean Association for the Study of Intestinal Disease (KASID) Multicenter Study.

Despite advances in imaging and endoscopic technology, diagnostic modalities for small bowel tumors are simultaneously performed. We investigated the discrepancy rate between each modality and predictive factors of discrepancy in patients with definite small bowel tumors. Data of patients with definite small bowel tumors who underwent both device-assisted enteroscopy (DAE) and computed tomography (CT) were retrieved from web-based enteroscopy registry database in Korea. Predictive risk factors associated with discrepancy were analyzed using logistic regression analysis. Among 998 patients, 210 (21.0%) were diagnosed with small bowel tumor using DAE, in 193 patients with definite small bowel tumor, DAE and CT were performed. Of these patients, 12 (6.2%) showed discrepancy between examinations. Among 49 patients who underwent DAE and video capsule endoscopy (VCE) examination, 13 (26.5%) showed discrepancy between examinations. No significant independent risk factors were associated with concordance between DAE and CT in multivariate logistic regression analysis among the patients. In a multivariate logistic regression analysis, red blood cell transfusion was negatively associated with concordance between DAE and VCE in patients with small bowel tumor (odds ratio, 0.163; 95% confidence interval, 0.026 to 1.004; p=0.050). For small bowel tumors, the discrepancy rate between DAE and CT was 6.2%, and 26.5% between DAE and VCE. Despite developments in cross-sectional imaging (VCE and DAE modalities), discrepancies still exist. For small bowel bleeding that require significant transfusion while showing insignificant VCE findings, DAE should be considered as the next diagnostic approach, considering the possibility of missed small bowel tumor.

Is there any difference between Eastern and Western clinical practice guidelines in management of gastric cancer?

Gastric cancer (GC) has been known as one of the most common causes of cancer mortality both in Western and Eastern countries. However, there might be differences between how it is managed in different countries. Thus, we aimed to investigate these differences. The most well-known clinical guidelines in field of GC management including Korean GC Association (KGCA), Japanese GC Association (JGCA), National Comprehensive Cancer Network (NCCN), European Society for Medical Oncology (ESMO), British Society of Gastroenterology (BSG), and National Institute for health and Care Excellence (NICE) have been reviewed. The contents of these guidelines were categorized under eight headings including (1) genetic predisposition, (2) prevention, (3) management of gastric polyp, atrophy, dysplasia and metaplasia, (4) diagnosis, (5) pathology and molecular biology, (6) treatment, (7) supportive and palliative care, and (8) follow up. Difference in each section was discussed. Considering KGCA and JGCA as Eastern and NCCN, ESMO, BSG, and NICE as Western guidelines, it is revealed that both sets of guidelines share common practices such as prioritizing comprehensive diagnostic evaluations, personalizing treatment plans, and palliative care. However, main differences can be seen in treatment regimens, the adoption of newer therapies like immunotherapy, and the utilization of emerging techniques such as HIPEC. These differences reflect the diverse clinical landscapes, research focuses, and healthcare systems within these regions.

Self-Reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire.

To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population. The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS. The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery. The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.

Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2019–2022)

Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2019–2022)

Russian Studies in Contemporary Korea

The Russian Language Department of Hankuk University of Foreign Studies (HUFS) —one of the leading universities of the Republic of Korea— was founded in the same year with the University and is about to celebrate its 70th anniversary. Today the University and the Russian Language Department are the main popularizers of the Russian language, literature, culture and Russian regional studies in South Korea. There are several associations: KASEUS — Korean Association of Slavic-Eurasian Studies; Russian Language and Literature Association (based on the HUFS — Hankuk University of Foreign Studies); KAR — Korean Association of Russian Studies (based on the Korean University); KASL — Korean Association of Slavic Languages (based on the Korean University); KATPR — Korean Association of Teachers and Teaching Staff of the Russian Language (whose members are university professors and school teachers); and KRA — Korea-Russia Association. The Korean-Russian Society of Art and Culture KORACS was established in 2013 to organize cultural exchange between Korea and Russia. The associations organize and conduct scientific conferences, symposiums, forums, and some publish their own journals. In South Korea, there are exchange programs for undergraduate and graduate students of Russian and Korean universities, and Russian professors are invited here to give lectures. Every spring the Hankuk University of Foreign Studies holds a Russian language Olympiad for students of Korean universities. This competition is of great interest to Korean students and is an incentive for deeper study of the Russian language. The Russian language and culture are represented and preserved here: there are Russian professors, school teachers, Russian-speaking Koreans and citizens of other countries. Therefore, despite the difficulties associated with changes in the socio-political situation, Russian studies in South Korea continue to develop. Interest in the Russian language, literature and culture does not wane since people always need to learn something new and wonderful and this is how Russian culture is characterized.