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.

Background: Impaired fasting glucose (IFG), being a pre-diabetic condition, can increase the risk of overt diabetes; thus early detection and prediction of IFG are important to reduce the incidence of overt diabetes. Some predictive factors, including serum alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), have been reported in several studies, but none of the studies have investigated the effect of longitudinal changes in individual serum ALT and GGT levels on the risk of IFG. Methods: We aimed to investigate the association between changes in the serum ALT and GGT levels and the risk of IFG using a checkup database between 1999 and 2014. Results: A total of 3,598 males and 3,275 females were enrolled in the study. We performed a follow-up test of serum ALT or GGT in each individual, and classified the cases in which the serum ALT or GGT level was increased or decreased during the follow-up test compared to the baseline. According to the multivariate Cox proportional hazards model, the hazard ratio was 1.76 (95% confidence interval, 1.45–2.12; P < 0.001) in male subjects with an increased serum GGT level compared to male subjects with a decrease in the serum GGT level at followup compared to the baseline. However, the relationship between the serum ALT level and incidence of new-onset IFG was not statistically significant in both sexes; and in females, the relationship between the serum GGT level and incidence of new-onset IFG was also not statistically significant. Conclusion We revealed that a longitudinal increase in serum GGT levels was related to an increased risk of IFG in males. Therefore, monitoring the changes in serum GGT levels is important for predicting new-onset IFG, and it can be used as an early indicator of onset of overt diabetes in males.

Rosai-Dorfman disease (RDD) is an uncommon proliferative histiocytic disorder of unknown etiology typically presenting as massive lymphadenopathy, and in some cases, with extranodal involvement. However, serous membranes are rarely involved in extranodal RDDs, and reports regarding pericardial involvement are scarce. Herein, we report a case of extranodal RDD manifesting as diffuse pericardial thickening and effusion in a 79-year-old man with monoclonal gammopathy. The patient complained of dyspnea, hence chest CT and PET scans were performed. They showed irregular thickening of the pericardium with a marked increase in metabolic activity. Pericardial biopsy showed the characteristic S100-positive and CD68-positive histiocytes exhibiting emperipolesis. The disease progressively evolved to bilateral pleural thickening with effusion of the pericardium, and finally led to death even with corticosteroid treatment. Although exceedingly rare, this case demonstrates the importance of RDD in the differential diagnosis of effusion in serous cavities based on imaging findings.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Rosai-Dorfman disease (RDD) is an uncommon proliferative histiocytic disorder of unknown etiology typically presenting as massive lymphadenopathy, and in some cases, with extranodal involvement. However, serous membranes are rarely involved in extranodal RDDs, and reports regarding pericardial involvement are scarce. Herein, we report a case of extranodal RDD manifesting as diffuse pericardial thickening and effusion in a 79-year-old man with monoclonal gammopathy. The patient complained of dyspnea, hence chest CT and PET scans were performed. They showed irregular thickening of the pericardium with a marked increase in metabolic activity. Pericardial biopsy showed the characteristic S100-positive and CD68-positive histiocytes exhibiting emperipolesis. The disease progressively evolved to bilateral pleural thickening with effusion of the pericardium, and finally led to death even with corticosteroid treatment. Although exceedingly rare, this case demonstrates the importance of RDD in the differential diagnosis of effusion in serous cavities based on imaging findings.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background and Objectives: This study aimed to analyze postoperative performance and mapping characteristics of cochlear implants (CIs) by comparing patients with autism spectrum disorder (ASD) to those without ASD, and to suggest CI mapping solutions in patients with ASD.Subjects and Method This retrospective study enrolled 10 children with ASD and hearing disabilities, who received simultaneous bilateral CI (ASD group), and 20 children with bilateral hearing disabilities, who received simultaneous bilateral CI at the same age (control group). CI performance was analyzed using speech perception tests (categorical auditory performance score and monosyllable, bisyllable, and Ling’s 6 tests) and a sound field test. The mapping characteristics focused on variables related to stimulus intensity and fine-tuning. Results: The performance of the ASD group was significantly poorer than that of the control group in all speech perception and sound field tests. At the comfortable (C) and threshold (T) levels, the ASD group scored significantly lower than the control group. The dynamic range of ASD group was significantly narrower than the control group. The ASD group had significantly lower pulse width, sensitivity, and volume than control group. Conclusion CI mapping in the ASD group showed practical limitations. To avoid overstimulation in patients with ASD, the dynamic range should be set narrow, or the C/T level should be set lower than normal. Key control factors, such as pulse width, sensitivity, and volume, should be set lower than the control group. Although lower performance from CI is generally expected in the ASD group, CI mapping in the ASD group requires a long-term approach with dedicated efforts and patience.

Background: The significance of risk modification in patients with acute coronary syndrome (ACS) is well recognized; however, the optimal timing for adminstering PCSK9 inhibitors remains unclear. Additionally, the lipid-lowering efficacy of evolocumab and alirocumab has not been fully established. This study evaluated the lipid-lowering effects of these two PCSK9 inhibitors. Methods: Patients diagnosed with ACS, including unstable angina, ST-segment elevation myocardial infarction, and non-ST-segment elevation myocardial infarction, who were treated with a PCSK9 inhibitor (evolocumab or alirocumab) during hospitalization for ACS between 2021 and 2023 were retrospectively analyzed. Baseline low-density lipoprotein cholesterol (LDL-C) levels were assessed, and changes in LDL-C levels during the acute and subacute phases after PCSK9 inhibitor administration were compared between the evolocumab and alirocumab groups. Results: Among 80 patients diagnosed with ACS, 36 received evolocumab, while 44 were treated with alirocumab. The mean baseline LDL-C level was 123 mg/dL in the evolocumab group and 128 mg/dL in the alirocumab group (p=0.456). In the subacute phase, the mean follow-up LDL-C levels were 47.05 mg/dL in the evolocumab group and 49.5 mg/dL in the alirocumab group (p=0.585). The mean percentage reduction in LDL-C levels during the subacute phase was 60.41% in the evolocumab group and 58.51% in the alirocumab group (p=0.431). These differences were not statistically significant. Conclusions No significant differences were observed between evolocumab and alirocumab. LDL-C levels exhibited a similar trend, characterized by a rapid decline in the acute phase, followed by a slight rebound in the subacute phase.

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.