Purpose: Molecular characteristics of synchronous colorectal cancers (SCRCs) remain incompletely elucidated, despite their importance in targeted therapy selection. We compared the molecular characteristics and somatic mutations between SCRCs. Materials and Methods: This retrospective study (2012-2014) included 98 consecutive patients with surgically resected SCRCs. Molecular characteristics, including microsatellite instability (MSI) and tumor-infiltrating lymphocytes (TILs), were analyzed for all cancer lesions. The intertumoral heterogeneity of SCRCs was evaluated using whole-exome sequencing (WES) for 18 cancers from nine patients with at least one MSI-high (MSI-H) tumor. Results: Twelve patients had at least one MSI-H tumor; five showed discordant MSI status. Mucinous adenocarcinoma frequency and TIL density were higher in patients with at least one MSI-H tumor than in those with only microsatellite-stable tumors. WES revealed that, except one patient (6.5%), most synchronous cancers shared few variants in each patient (0.09%-0.36%). The concordance rates for BRAF, KRAS, NRAS, and PIK3CA, in synchronous cancers from each patient were 66.7%, 66.7%, 66.7%, and 55.6%, respectively. Conclusion Although synchronous cancers shared a mutated gene, the mutation subtypes differed. SCRCs exhibited 5.1% MSI status discordance rate and a high discordance rate in somatic mutational variants. As intertumoral heterogeneity may affect the targeted therapy response, molecular analysis of all tumors is recommended for patients with SCRCs.

Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.

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.

Myopia, particularly high myopia, is a significant risk factor for several ocular pathologies including cataract, glaucoma, and retinal detachment. Excessive axial elongation associated with high myopia can induce biomechanical stretching, increasing the risk of serious complications like posterior staphyloma and myopic maculopathy. Global meta-analyses estimate that approximately 10 million people were visually impaired due to myopic maculopathy in 2015, with 3 million being blind. Recent nationwide surveys in South Korea revealed a prevalence of 65.4% for myopia and 6.9% for high myopia in children and adolescents, highlighting the urgent need for effective management. Delaying the onset and slowing the progression of myopia during childhood and adolescence is crucial for reducing the potential lifetime risk of these complications. This consensus statement, prepared by the Korean Myopia Society for the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS), reviews the current evidence for myopia control interventions and provides management strategies applicable to the South Korean clinical setting. Key interventions covered include lifestyle modifications (outdoor time, near work adjustment), optical methods (myopia-control spectacle lenses, dual-focus soft contact lenses, orthokeratology), and pharmacologic treatment (low-concentration atropine), as well as combination therapies. The statement also addresses patient selection, treatment outcome evaluation using spherical equivalent and axial length changes, and the crucial aspects related to treatment cessation and the rebound effect.

Purpose: We aimed to investigate the prevalence and genotype distribution of human papillomavirus (HPV) among Korean males and explore implications for targeted vaccination strategies. Materials and Methods: A total of 44,065 males underwent HPV testing between March 2014 and February 2022 using the Anyplex™ II HPV 28 system, detecting 19 high-risk (HR) and 9 low-risk (LR) HPV types. Additionally, data from 507 male patients at local clinic (2017–2022) were analyzed to compare genotype prevalence between those with (WAT group) and without (WAT X group) genital warts. Results: Overall HPV positivity was 59.1%. HPV 6 (33.3%) and HPV 11 (11.0%) were the most prevalent LR genotypes, while HPV 16 (5.2%) dominated HR infection. Multiple HPV genotype co-infection occurred in 49.3% of positive cases, with 11.3% involving multiple HR types. Younger males (teens, 20s) exhibited higher HR-HPV positivity, although total HPV positivity peaked in the 40s (60.1%). Non–9-valent HR genotypes (HPV 53, 51, 39, 66) accounted for 27.6%–35.0% of infections annually. At local clinic, HPV 43 was significantly associated with genital warts (p=0.017). Conclusions These data support including males in national HPV vaccination strategies using the current 9-valent vaccine and underscore the need for ongoing genotype surveillance to monitor non‑vaccine high‑risk types and inform public health policy, and support inclusion of males in national HPV vaccination strategies using the current 9‑valent vaccine.

In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Background and Objectives: Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association. Materials and Methods: We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size. Results: The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend ＜0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older. Conclusion In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.

suggest that some reproductive factors associated with BC differ across ethnicities and time trends, perhaps due to the prevalence of reproductive factors and the baseline hazard of BC.

The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.

Conversion therapy is a treatment strategy that shifts from palliative systemic therapy to curative surgical treatment for primary and/or metastatic stage IV gastric cancer (GC).To address its clinical statements, the Korean Gastric Cancer Association aims to present a consensus on conversion therapy among experts attending KINGCA WEEK 2024. The KINGCA Scientific Committee and Development Working Group for Korean Practice Guidelines prepared preformulated topics and 9 clinical statements for conversion therapy.The Delphi method was applied to a panel of 17 experts for consensus and opinions. The final comments were announced after the statement presentation and discussed during the consensus meeting session of KINGCA WEEK 2024. Most experts agreed that conversion herapy provides a survival benefit for selected patients who respond to systemic therapy and undergo R0 resection (88.3%). Patients with limited metastases were considered good candidates (94.2%). The optimal timing was based on the response to systemic therapy (70.6%). The regimen was recommended to be individualized (100%) and the duration to be at least 6 months (88.3%). A minimally invasive approach (82.3%) and D2 lymph node dissection (82.4%) were considered for surgery. However, resection for metastases with a complete clinical response after systemic therapy was not advocated (41.2%). All experts agreed on the need for large-scale randomized-controlled trials for further evidence (100%).Recent advancements in treatment may facilitate radical surgery for patients with stage IV GC. Further evidence is warranted to establish the safety and efficacy of conversion therapy.