Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Objectives: This study aimed to develop a NOVA-based scoring approach for evaluating ultra- processed food (UPF) intake among Korean adults and to examine its performance. Previous studies have reported that young adults have the highest levels of UPF consumption. Accordingly, this study focused on adults aged 19–40 years and developed scoring components reflecting dietary patterns specific to Korean eating habits. Methods: Using 24-hour dietary recall data from adults aged 19–40 years in the Korea National Health and Nutrition Examination Survey (2021–2023), foods were classified according to the Korean-adapted NOVA system. The top 10 food groups accounting for ≥ 80% of cumulative UPF-derived energy were selected to construct the scoring components. The tool was operationalized using food frequency questionnaire (FFQ) data from the Gangwon cohort study (2022–2024). Intake frequencies were converted into scores ranging from 0 (“rarely or never”) to 5 (“≥ 1 time/day”), and summed to generate the NOVA–UPF score (range: 0–50). Results: Among 237 young adults (aged 20–49 years), the mean NOVA–UPF score was 22.9 ± 8.3. A positive association was observed between the NOVA–UPF score and FFQbased UPF energy intake (Spearman’s ρ = 0.629, P < 0.001). Cross-classification showed that 51.9% were classified into the same tertile and 94.9% into the same or adjacent tertiles, with a weighted kappa coefficient of 0.279. Conclusion This NOVA-based scoring approach may serve as a preliminary tool for assessing UPF intake in Korean young adults. Further refinement and rigorous validation using quantitative dietary assessment methods and more diverse populations are required before broader application.

Background: Menopausal status can increase the risk of cardiocerebrovascular diseases (CCVDs) in women with type 2 diabetes mellitus (T2DM). Regular exercise is well-known to reduce this risk. This study explored the impact of exercise on CCVD and mortality in women with T2DM according to their menopausal status. Methods: A total of 32,477 premenopausal and 53,690 postmenopausal Korean women with T2DM aged 40 to 60 years from a national health examination cohort (2009 to 2018) were included. We evaluated risks for stroke, myocardial infarction (MI), and mortality based on exercise intensity. Cox proportional hazard regression analyses were performed to obtain the adjusted hazard ratio (aHR) and 95% confidence interval. Results: Exercise reduced stroke, MI, and mortality risks in women with T2DM, regardless of menopausal status. The highest effects of aHR compared to the sedentary group were 0.68 for stroke, 0.66 for MI, and 0.81 for mortality. Postmenopausal women experienced significant MI risk reductions at most exercise intensities, with the greatest reduction in the ≥1,500 metabolic equivalent of task score group unlike premenopausal women. However, stroke and mortality risk reductions in postmenopausal women were less pronounced compared to premenopausal women. Conclusion Exercise reduces CCVD risk in women with T2DM across menopausal status. Postmenopausal women with T2DM had more benefits from exercise on MI but fewer benefits on stroke and mortality than premenopausal women. In premenopausal women with T2DM, exercise was not associated with a lower MI risk.

Objective: : This study aimed to identify risk factors predicting the loss of cervical lordosis (LCL) in patients with multilevel ossification of the posterior longitudinal ligament (OPLL) after laminoplasty. Additionally, we evaluated the impact of these factors on health-related quality of life (HRQOL). Methods: : We retrospectively analyzed data from patients who underwent laminoplasty at Chonnam National University Hospital between January 2013 and December 2022. A range of radiological parameters and clinical outcome measures were collected perioperatively. Patients were divided into two groups based on the severity of LCL. We then evaluated preoperative radiological parameters associated with LCL and clinical outcomes, including HRQOL. Results: : A total of 110 patients (93 men and 17 women; mean age, 61.31±10.80 years) were included in the analysis. A higher T1 slope (T1S) (β=-0.412; p=0.004) and a lower extension ratio (β=0.107; p=0.006) were associated with an increased risk of LCL. T1S proved to be an excellent predictor of LCL, with a cutoff value of 28° (p<0.001; area under the curve, 0.918). Furthermore, T1S was the only factor significantly correlated with HRQOL after laminoplasty (r=-0.330; p<0.001). Conclusion : T1S was significantly associated not only with LCL but also with HRQOL among patients with multilevel OPLL after laminoplasty. With a T1S cutoff of 28°, a T1S exceeding this threshold can be considered an important prognostic factor when planning laminoplasty in these patients.

Background: Despite the rising incidence of end-stage renal disease (ESRD) among individuals with type 2 diabetes mellitus (T2DM) in Korea, no predictive model or nomogram has been developed using a nationwide cohort. In this study, we developed a nomogram to predict the long-term risk of ESRD in patients with T2DM using a large-scale, population-based Korean database. Methods: Using the Korean National Health Insurance Database, patients with T2DM who underwent health examinations between 2015 and 2016 were assigned as development (n=1,744,277) and validation (n=747,407) cohorts. New ESRD cases were identified using codes for renal replacement therapy. A Cox proportional hazards regression model was used to derive a risk-scoring system, and 13 variables were selected. A risk score nomogram was then created to estimate the risk of ESRD. Results: In the development cohort, 8,631 patients with T2DM developed ESRD during a follow-up period of 4.8±0.9 years. After multivariable adjustment, significant predictors of ESRD included male sex, current smoking, physical inactivity, low income, low body mass index, hypertension, low-density lipoprotein cholesterol ≥160 mg/dL, chronic kidney disease, insulin use, and longer duration of T2DM. A final nomogram incorporating 13 variables was developed to estimate the individual probability of ESRD. The concordance index for ESRD prediction in the validation cohort was 0.906 (95% confidence interval, 0.9 to 0.912). Conclusion This 13-variable nomogram provides a simple tool for identifying patients with T2DM at high risk of ESRD and may aid in early intervention.

Background: The prevalence of diabetes mellitus and early-onset dementia (EOD), defined as dementia diagnosed at an age <65 years, is increasing worldwide, with significant socioeconomic implications. We investigated the association between diabetes, prediabetes, and EOD, focusing on the influence of diabetes duration on EOD risk. Methods: Using the Korean National Health Insurance Service database, we analyzed data from 1,979,509 patients aged 40–60 years who underwent health checkups in 2009. Patients were categorized into five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes duration <5 years, and diabetes duration ≥5 years. Cox proportional hazard models were used to estimate the adjusted hazard ratios (aHRs) for EOD after adjusting for demographic and clinical covariates. Results: During the observation period (mean 7.75 years), 8,921 patients with EOD were identified. The diabetes group demonstrated a significantly higher incidence of EOD compared to the normal group (aHR, 1.334; 95% confidence interval [CI], 1.226 to 1.451). EOD risk increased with longer diabetes duration, with the highest risk observed in patients with diabetes ≥5 years (aHR, 1.543; 95% CI, 1.368 to 1.741). No significant difference was observed between the IFG and normal groups (aHR, 0.989; 95% CI, 0.938 to 1.043). Additionally, the hypertension group exhibited a significantly higher incidence of EOD compared to the non-hypertension group (aHR, 1.364; 95% CI, 1.291 to 1.442). Conclusion Diabetes is independently associated with increased risk of EOD, and this risk increases with longer diabetes duration. This association remained significant regardless of the presence and duration of hypertension.

Purpose: Langer's axillary arch (LAA) is a common muscular variant that may affect the assessment of axillary lymph nodes in breast cancer. We investigated whether the presence of the LAA had a meaningful clinical impact in a large cohort of Korean patients with breast cancer. Methods: The medical records and imaging of 2,904 patients (2,953 cases) who underwent axillary surgery for breast cancer were reviewed. The presence of LAA was determined using chest computed tomography scans. The number of retrieved lymph nodes, the accuracy of axillary ultrasonography, and survival outcomes were compared between the LAA and nonLAA groups. Results: The LAA muscle was identified in 301 patients (10.2%). Preoperative ultrasound evaluation showed a lower specificity in the LAA group (77.9% vs. 83.6%, p = 0.031).Additionally, invasive disease-free survival (iDFS) was significantly worse in the ‘LAA-positive patients’ after adjusting for stage, histologic grade, and treatment (adjusted hazard ratio, 2.00; 95% confidence interval, 1.00–4.01; p = 0.048), with regional axillary recurrence being notably more frequent in patients with the LAA muscle (p = 0.005). Conclusion The presence of the LAA muscle was associated with reduced specificity on preoperative ultrasound. Patients with LAA muscle-associated tumors had worse iDFS, with regional axillary recurrence occurring more frequently. Recognition of the LAA muscle during axillary staging and surgery may improve nodal assessment accuracy and outcomes, especially in the era of axillary surgery de-escalation.

Purpose: Declines in masticatory function have been reported to be closely associated with cognitive impairment and reduced brain activity in older adults. This study aimed to investigate the effects of intraoral vibratory stimulation on masticatory function, cognitive performance, and brain activity in elderly individuals and to evaluate its potential efficacy. Materials and Methods: Participants were divided into a vibration-stimulation group (n=9) and a non-vibration control group (n=7). Baseline assessments were conducted at the first visit. Participants then received either vibratory stimulation or a wash-out (control) condition for two weeks, followed by the same assessments at the final visit. Evaluation measures were dental assessments (maximum bite force, masticatory performance, and salivary flow rate), cognitive tests (CANTAB, paper-based and computerized tests), quantitative electroencephalography (qEEG), and functional magnetic resonance imaging (fMRI) during a short-term memory task. Results: No significant long-term effects or statistically meaningful differences were observed between the two groups in cognitive performance or brain activity. Similarly, no pre- to post-intervention differences were found between groups in dental measures related to masticatory function (maximum bite force, masticatory performance, and salivary flow rate). Due to the limited sample size, this study functioned as a pilot study focusing on descriptive rather than inferential statistical analysis. Conclusion Intraoral vibratory stimulation did not demonstrate immediate or clear effects on cognitive function or brain activity in older adults, suggesting the need for optimization of stimulation parameters such as location and intensity. Future studies with larger sample sizes and improved stimulation methods replicating masticatory function are warranted to further explore the potential cognitive benefits.