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.

Background: Current guidelines recommend factor IIa- or Xa-specific inhibitors over warfarin analogs for preventing thromboembolic stroke in patients with atrial fibrillation (AF).However, their plasma concentrations in Korean patients are not well understood. Methods: We conducted a single-center laboratory study to determine the distribution ranges of peak and trough concentrations of three factor Xa inhibitors (apixaban, edoxaban, and rivaroxaban) prescribed for preventing strokes in patients with AF. Patients receiving one of these drugs and undergoing blood specimen collection for laboratory tests were screened. Blood specimens were obtained from patients who had adhered to the prescribed drug regimen consistently for at least 1 week. Drug plasma concentrations were measured using heparin liquid-reagent technology-based anti-Xa chromogenic assays. Results: We selected 459 patients who were taking standard or on-label-reduced doses of apixaban (N = 252), edoxaban (N = 182), or rivaroxaban (N = 25). The 5th–95th percentile ranges of the peak concentrations were 84–414 ng/mL (apixaban), 72–424 ng/mL (edoxaban), and 97–517 ng/mL (rivaroxaban). The respective 5th–95th percentile ranges of the trough concentrations were 44–237 ng/mL, 23–93 ng/mL, and 13–219 ng/mL. Approximately 19.6% (apixaban), 33.3% (edoxaban), and 64.0% (rivaroxaban) of patients in each group had peak concentrations out of the predicted distribution ranges based on pharmacokinetic data. Approximately 7.3%, 52.8%, and 8.3% of patients had trough concentrations out of the predicted distribution ranges. Conclusions A considerable proportion of Korean patients with AF taking factor Xa inhibitors may require population-specific reference ranges to guide therapeutic monitoring.

Purpose: Patient-derived cells (PDCs) and patient-derived organoids (PDOs) are complementary preclinical models widely used in translational cancer research. However, their molecular and functional differences have not been systematically characterized. This study established and analyzed paired PDC and PDO models derived from the same gastric cancer ascites to delineate platform-dependent molecular and functional profiles. Materials and Methods: Malignant ascites or pleural fluid obtained from 6 patients with advanced gastric cancer were used to establish paired PDC and PDO models. All pairs underwent comprehensive multi-omics profiling, integrating genomic, transcriptomic, and proteomic data. Phenotypic characterization included morphological, histological, proliferative, and cell cycle analyses. Drug sensitivity assays were performed using 4 chemotherapeutic agents commonly used to treat gastric cancer. Results: The 6 paired PDC and PDO models exhibited distinct morphological characteristics.Whole-genome analyses demonstrated high concordance among primary tumors, PDCs, and PDOs, confirming tumor representation across platforms. Multi-omics profiling identified platform-dependent molecular signatures; PDOs were enriched for extracellular matrix remodeling and stemness, whereas PDCs displayed proliferation- and immune-related signatures. Clinically relevant biomarkers, including HER2 and MET alterations, were concordant with primary tumors. Notably, drug responses differed between platforms and patients, indicating platform-dependent and patient-specific chemosensitivity. Conclusions Paired PDC and PDO models derived from the same patients preserved core patient-specific tumor characteristics while exhibiting distinct molecular and functional profiles. These findings underscore the culture platform as a critical determinant of experimental outcomes and therapeutic responses. Therefore, careful selection of an appropriate preclinical model is essential to accurately address biological questions and optimize precision oncology strategies.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: This study evaluated long-term trends in gastric cancer epidemiology and survival with a focus on conditional relative survival (CRS). Materials and Methods: Using the Korea Central Cancer Registry, we analyzed 665,184 patients who were newly diagnosed with gastric cancer between 1999 and 2022.The study period was divided into four intervals: Period I (1999–2005), Period II (2006–2011), Period III (2012–2017), and Period IV (2018–2022). Temporal trends in the incidence and mortality were assessed using crude and age-standardized rates. Relative survival was estimated using the Ederer II method, and the 5-year CRS was calculated according to the survival duration after diagnosis. Results: The incidence of gastric cancer increased until 2011 and subsequently declined, with a marked decrease observed in 2020. Individuals aged ≥70 years consistently had the highest incidence rates. Mortality rates showed a sustained decline throughout the study period. The overall 5-year relative survival improved from 69.8% in Period II to 78.4% in Period IV. The 5-year CRS increased from 86.1% at 1 year after diagnosis to 96.3% at 5 years.Patients with localized stage maintained a 5-year CRS above 95% at 1 year after diagnosis, whereas those with regional and distant stages showed 5-year CRS that consistently remained below 95%. Conclusions The incidence and mortality rates of gastric cancer in Korea have declined over the past two decades, accompanied by improved survival outcomes. The CRS analysis suggests that long-term follow-up is warranted, with the optimal duration varying according to patient characteristics.

Purpose: We aimed to compare broad-spectrum antibiotic use between hospice and nonhospice patients with cancer at the end of life using nationwide data from Korea. Methods: In this retrospective cohort study, we analyzed the Korean National Health Insurance Service data of adult patients with cancer who died between 2018 and 2021. Hospice users were defined as patients who received inpatient, home-based, or consultation-based hospice care before death. We applied propensity score matching (1:2) to balance the baseline characteristics of the hospice and non-hospice groups. Broad-spectrum antibiotic use, including anti-pseudomonal penicillins, anti-pseudomonal cephalosporins, carbapenems, and glycopeptides, was assessed during the last 3 months of life using prescription proportions and days of therapy per 1,000 patient-days. Results: After matching, 38,102 hospice and 75,736 non-hospice users were analyzed. During the last 3 months of life, 74.6% of hospiceand 79.0% of non-hospice users received at least one broad-spectrum antibiotic (P＜0.001).The proportion of patients receiving broad-spectrum antibiotics was generally lower amonghospice users across all time intervals (P＜0.001), and the number of days of therapy wasalso lower, with the largest differences observed during the final week and last 3 days of life.Subgroup analyses showed the highest antibiotic exposure among patients with hematologic and pancreatobiliary cancers, particularly in the non-hospice group. Conclusion Hospice involvement was associated with lower use and reduced exposure to broad-spectrum antibiotics among patients with cancer near the end of life. These findings support the alignment of end-of-life treatment decisions with the comfort-oriented goals of hospice care.

Severe midfoot Charcot neuroarthropathy (CN) presents a significant surgical challenge because of extensive bone loss and poor bone quality. This report presents the outcome of a case treated with realignment arthrodesis using a superconstruct technique, supplemented by the postoperative use of denosumab. A patient with Eichenholtz Stage III CN (Brodsky Type 1 and 2) underwent a single-stage surgical reconstruction. Postoperatively, denosumab was administered to enhance bone stability. The 1-year and 1-month follow-up showed that the severe deformity had been successfully corrected to a stable, plantigrade foot, confirmed by radiographic and clinical evaluation.This case suggests that a combined surgical approach using a superconstruct with adjuvant denosumab can be an effective treatment for severe midfoot CN.

Legal risks and liability issues in medical practice serve as a primary catalyst for the current collapse of essential healthcare services in Korea. Currently, medical disputes in Korea are disproportionately focused on criminal prosecutions and high-damages civil litigation. This punitive approach fosters a culture of concealment, encourages defensive medicine, and accelerates the exodus of medical professionals from essential fields. Ultimately, this cycle deprives the system of opportunities for improvement and poses a significant threat to patient safety. In contrast, many advanced nations have adopted principles of “Just Culture” and “Safe Space,” prioritizing non-punitive reporting and systemic root-cause analysis over individual retribution. To address these issues, this paper proposes four key strategies: First, the establishment of an independent “Patient Safety Investigation Agency” to objectively investigate incidents and identify systemic flaws. Second, a transition from criminal punishment to licensing board-led management, focusing on re-education and counseling to maintain quality of care. Third, the enactment of “Apology Laws” to ensure that expressions of regret or apologies cannot be used as legal evidence of liability, thereby fostering trust and psychological recovery. Finally, the creation of a “Patient Safety Fund” to provide prompt and sufficient public compensation to victims regardless of proven negligence. In conclusion, it is imperative to shift the paradigm by defining medical accidents as “system failures” rather than individual faults. Strengthening the social safety net will encourage medical professionals to return to essential care and build a sustainable healthcare environment centered on patient safety.

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.

Objective: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy (ET) constitute the standard systemic treatment for estrogen receptor-positive, human epidermal growth factor 2-negative (ER+/HER2-) metastatic breast cancer (MBC). However, treatment responses remain heterogeneous, highlighting the need for reliable prognostic markers. This study aimed to evaluate the prognostic significance of 18F-fluorodeoxyglucose (FDG) PET/CT findings in this setting. Materials and Methods: This retrospective single-center cohort study included patients with ER+/HER2- MBC who underwent18F-FDG PET/CT before initiating CDK4/6 inhibitors plus ET between 2018 and 2023. Maximum standardized uptake value(SUVmax), whole-body metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. Progression-free survival (PFS) and overall survival (OS) were evaluated as the primary and secondary outcomes, respectively, using multivariable Cox models. PET parameters (SUVmax, MTV, and TLG) were analyzed as both continuous and dichotomized variables based on median values, adjusting for relevant clinical covariates. Results: Among the 374 patients, 82 (21.9%) presented with de novo metastatic disease, and 357 (95.5%) received CDK4/6 inhibitors as first-line therapy. In multivariable Cox analysis, all continuous PET parameters were independently associated with PFS (adjusted hazard ratio for SUVmax 1.05 [95% confidence interval 1.02–1.08]; log-transformed MTV 1.16 [1.08–1.25]; and log-transformed TLG 1.14 [1.07–1.23]) and OS (SUVmax 1.08 [1.04–1.11]; log-transformed MTV 1.24 [1.12–1.38]; and log-transformed TLG 1.22 [1.11–1.34]) with all P < 0.001. Results based on dichotomized PET parameters were similar to those obtained with continuous values: PFS (adjusted hazard ratio for SUVmax ≥ 7.6, 1.41 [1.08–1.85]; MTV ≥ 21.2 cm 3 , 1.41 [1.08–1.86]; and TLG ≥ 78.9, 1.51 [1.14–1.99]) with P ≤ 0.013 and OS (1.43 [1.01–2.04]; 1.84 [1.28– 2.66]; and 1.73 [1.20–2.50], respectively) with P ≤ 0.046. Conclusion Pretreatment 18F-FDG PET/CT parameters are independent prognostic markers in patients with ER+/HER2- MBC receiving CDK4/6 inhibitors with ET, supporting their potential utility in risk stratification.