Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Gastroesophageal reflux disease (GERD) is a chronic and relapsing gastrointestinal disorder characterized by the reflux of gastric contents into the esophagus, leading to troublesome symptoms and/or complications. Since the publication of the 2020 Seoul Consensus on GERD, significant new evidence has emerged, particularly regarding acid-suppressive therapies and diagnostic approaches. This 2025 focused update aims to refine GERD management strategies by incorporating the latest evidence on acid suppressive therapies and regional considerations in Asian populations. This study builds on the 2020 Seoul Consensus by integrating systematic reviews, meta-analyses, and expert consensuses to offer updated recommendations for the definition and medical treatment of GERD. These guidelines incorporate recent advances in acid-suppressive therapies, particularly potassium-competitive acid blockers, and adopt updated diagnostic frameworks in accordance with the Lyon Consensus 2.0. Key clinical questions were identified and structured using the following format: Population, Intervention, Comparator, Outcome. The resulting recommendations address the initial treatment, long-term maintenance strategies, and role of personalized therapy based on disease severity, such as the grade of reflux esophagitis. Six key statements are presented: updated definition and classification of GERD (Statement 1); initial and long-term treatment strategies tailored to GERD phenotypes, such as non-erosive reflux disease, mild erosive esophagitis, and severe erosive esophagitis (Statements 2-5); and dose optimization strategies for long-term safety (Statement 6). These guidelines aim to support gastroenterologists and general healthcare providers in making individualized evidence-based decisions for GERD management.

Korea’s healthcare system is at a critical juncture as rapid population aging, rising chronic disease burdens, and fragmented care expose the limits of a hospital-centered, fee-for-service model. Although policy discussions have long emphasized strengthening primary care and introducing a “family doctor” system, past reforms have focused mainly on expanding services or redefining professional roles, without establishing clear accountability, care continuity, or aligned payment mechanisms. Consequently, primary care remains weak and responsibility for comprehensive patient management is diffuse. This article argues that meaningful reform requires redefining the primary physician as an accountable manager of longitudinal, coordinated care within an integrated delivery and payment framework. Drawing on experiences from the United States, the United Kingdom, and several European countries, it identifies common features of successful primary care–oriented systems, including patient registration, team-based care, risk-adjusted payment, and explicit outcome accountability. Based on these insights, the authors propose a Korean primary physician model tailored to solo and small-group practices while fostering regional collaboration. Core elements include voluntary patient registration, multidisciplinary primary care teams, risk-stratified care management, regional care networks, and a mixed payment model combining per-member-per-month payments, shared savings, and performance-based incentives. The article emphasizes phased pilot testing focused on operational feasibility. Ultimately, transitioning to a primary care–centered system is presented as a strategic necessity for sustainability and improved care continuity.

The South Korean resident training system is currently at a critical turning point, facing structural crises characterized by excessive labor-intensive environments and deteriorating quality of education. Since the medical standoff in 2024, the limitations of relying on junior doctors’ labor for hospital operations have become increasingly apparent. This review examines the current status and problems of the resident training system, including long working hours exceeding Organisation for Economic Co-operation and Development (OECD) standards, lack of systematic competency-based education, and worsening regional and essential medical imbalances. By analyzing international cases from the United States, United Kingdom, Japan, and Australia, this article proposes four core strategies for reform: (1) establishing a sustainable working and educational environment through the expansion of hospitalist systems and legalizing physician assistant roles; (2) innovating the curriculum and evaluation systems based on entrustable professional activities and milestones; (3) implementing a network-based training model to bridge the gap between metropolitan and regional healthcare; and (4) securing stable financial support and strengthening governance through the establishment of an independent evaluation body (e.g., K-ACGME). Ultimately, reforming the training system is essential not only for the rights and professional growth of residents but also for ensuring patient safety and the long-term sustainability of the national healthcare system.

Purpose: Although host body composition, nutritional and systemic inflammatory status have been suggested to have an impact on prognosis in patients with colorectal cancer (CRC), their impact on patients with stage IV CRC remains unclear.This study investigated the prognostic effects of those parameters in patients initially diagnosed with stage IV CRC who underwent surgery. Methods: Patients with stage IV CRC who underwent surgery were selected. Preoperative computed tomography images were evaluated for skeletal muscle index, skeletal muscle density (SMD), visceral fat area (VFA), and subcutaneous fat area (SFA). For nutritional status and systemic inflammation, prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) were used. The Cox proportional hazard model was used to evaluate the prognostic significance of progression-free survival (PFS) after adjustment for the other covariates in the model. Results: Data of 134 patients with stage IV CRC who underwent surgery between January 2005 and February 2014 were included. SMD, VFA, SFA, PNI, NLR, LMR, and PLR were associated with PFS in the univariable analysis. In the multivariable analysis, SFA (hazard ratio [HR], 0.612; 95% confidence interval [CI], 0.389–0.961; P = 0.033), and PNI (HR, 0.536; 95% CI, 0.345–0.832; P = 0.005) were identified to be independent prognostic factors for PFS. Conclusion SFA and PNI both demonstrated prognostic significance in patients with stage IV CRC. Accordingly, we believe further studies are warranted to determine whether incorporating these factors can aid in surgical decision-making for stage IV CRC patients.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine that selectively targets cancer cells and induces apoptosis. However, many cancers, including bladder cancer, develop resistance to TRAIL, limiting the efficacy of TRAIL-based therapies. This study investigated whether betulinic acid (BA), a pentacyclic triterpenoid with anticancer and chemosensitizing properties, increases TRAIL-mediated apoptosis in TRAIL-resistant human bladder cancer cells. Combination treatment with BA and TRAIL significantly increased cytotoxicity and apoptosis compared to either treatment alone. This combination treatment also increased reactive oxygen species (ROS) production, increased Bax expression and Bid cleavage (tBid formation), and downregulated Bcl-2 levels. These effects were accompanied by caspase activation via extrinsic and intrinsic pathways, leading to cytochrome c release via mitochondrial membrane destabilization, thereby contributing to increased apoptosis. Furthermore, the combination treatment inhibited phosphoinositide 3-kinase (PI3K) and Akt phosphorylation; this effect was amplified by a PI3K inhibitor but abrogated by ROS inhibition. Collectively, our results suggest that BA sensitizes bladder cancer cells to TRAILinduced apoptosis via ROS-dependent activation of the apoptotic pathway and inhibition of PI3K/Akt signaling. Therefore, the BA and TRAIL combination exhibits potential to overcome TRAIL resistance in human bladder cancer.

Objective: : A twig-like middle cerebral artery (T-MCA) is a rare condition characterized by steno-occlusion of the M1 segment of the middle cerebral artery (MCA) with nearby collateral arterial networks. Despite unclear pathophysiology, it is often classified as a congenital anomaly caused by failure of fusion of the plexiform MCA arterial plexus. We aimed to improve understanding of the pathophysiology of T-MCAs by analyzing incidental T-MCA findings and their natural history. Methods: : A retrospective chart review was performed between January 2011 and December 2023 at three medical centers treating both ischemic and hemorrhagic strokes. Patients with suspected MCA lesions were selected through radiology reports from computed tomography, magnetic resonance angiography, and digital subtraction imaging. Results: : We identified 51 T-MCA cases from a radiology report search spanning 13 years across three medical centers. The study included 9875 patients with ischemic stroke and 2097 with hemorrhagic stroke. Of the 51 T-MCA cases, incidental findings accounted for 25 (49.0%), ischemic stroke for 18 (35.3%), and hemorrhagic strokes accounted for eight cases (15.7%). T-MCA related ischemic and hemorrhagic strokes accounted for 0.18–0.38% of all strokes. The RNF213.R4810K mutation was identified in seven of 15 patients (46.7%) tested. We found three cases of a de-novo T-MCA that progressed from a normal MCA architecture. Conclusion : T-MCAs may represent an acquired secondary anomaly rather than a congenital lesion, followed by steno-occlusion of the focal MCA with new arterial network formation. Both Moyamoya angiopathy and chronic atherosclerosis likely contributed to disease progression. Formation of a microaneurysm, dilatation of the lenticulostriate artery, and hemodynamic stress can lead to stroke.

Objective: To investigate the longitudinal association between sarcopenia and depressive symptoms in community-dwellingolder adults, focusing on sex-specific differences. Methods: This 2-year prospective study utilized data from the Korean Frailty and Aging Cohort Study. We included 1,366participants (700 men, 666 women) aged 70-84 years who were free of depressive symptoms (Short Geriatric Depression Scale-Korean [SGDS-K]<8) at baseline. Sarcopenia status (no sarcopenia, sarcopenia, severe sarcopenia) was defined by the AsianWorking Group for Sarcopenia 2019 criteria. Multivariate logistic regression analysis was performed to assess the association be-tween baseline sarcopenia and incident depressive symptoms (SGDS-K≥8) at follow-up, adjusting for covariates. Results: After adjustment, baseline severe sarcopenia was significantly associated with a higher risk of incident depression (adjusted odds ratio [aOR]=3.040, 95% confidence interval [CI]=1.494-6.188). In the sex-stratified analysis, this association remained robust only in men (aOR=3.344, 95% CI=1.332-8.395), but was not statistically significant in women (aOR=2.490, 95% CI=0.699-8.872, p=0.159). Conclusion Severe sarcopenia independently predicts for 2-year development of depressive symptoms, particularly amongolder Korean men. These findings highlight a significant sex difference in the temporal relationship between sarcopenia and de-pression for older men.

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.