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.

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.

Acute peritonitis is a life-threatening condition that, if left untreated, can rapidly progress to death owing to intra-abdominal sepsis. Here, we report an autopsy case of a 46-year-old Uzbek man who had experienced abdominal pain for about a month but died without timely medical intervention due to barriers to accessing care associated with his undocumented status. Autopsy revealed more than 1,600 mL of purulent ascites in the peritoneal cavity and localized purulent collection in the omentum. Culture of ascitic fluid collected at autopsy yielded bacterial growth, and subsequent 16S rRNA gene sequencing identified Klebsiella variicola, an emerging pathogen frequently misidentified as K. pneumoniae and associated with higher mortality in bloodstream infections, together with Phytobacter massiliensis (formerly Metakosakonia massiliensis), a recently reclassified taxon rarely reported as a cause of human intra-abdominal infection. This case highlights the forensic value of molecular diagnostics for accurate pathogen identification in postmortem investigations, with social barriers contributing to delayed presentation, which allows the infection to progress to a fatal outcome.

Purpose: This study investigated the risk of radiation-associated heart disease (RAHD) in Korean women treated with radiotherapy (RT) for breast cancer (BC) using data from the National Health Insurance Service database. Materials and Methods: A retrospective cohort analysis was conducted on 65,188 patients with BC treated with RT between 2009 and 2014 and 325,940 controls without BC or prior coronary artery disease (CAD), with 1:5 exact matching by age, type 2 diabetes mellitus, hypertension, and dyslipidemia status. CAD encompassed both incident events and fatal events. Competing risk analysis was conducted to estimate subdistribution hazard ratio (HR) with 95% confidence interval (CI) for CAD, setting mortality from non-CAD causes as a competing risk. Results: During the mean 9.9 years of follow-up period, 3,852 (1.0%) CAD and 20,999 (5.4%) death from non-CAD causes were reported. Compared to controls, participants with BC who received RT had a significantly lower risk of CAD incidence. HR (95% CI) for CAD in the BC with RT group was 0.66 (0.60-0.73, p < 0.001). On the other hand, HR (95% CI) for mortality from non-CAD causes was 3.57 (3.48-3.67, p < 0.001). Conclusion In this large population-based cohort study, breast cancer patients who received RT did not show an increased incidence of CAD compared with the general population without breast cancer. Individual-level dosimetric data and longer follow-up are needed to clarify the independent risk.

Purpose: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Limb salvage surgery using a tumor prosthesis for the treatment of malignant bone tumors in the proximal femur is an effective method for preserving hip joint function. On the other hand, maintaining hip joint stability can be challenging because of the extensive resection of the bone and surrounding soft tissue. This paper reports an unusual case of hip dislocation in a patient with a proximal femoral osteosarcoma who underwent limb salvage surgery. Over six years, the tumor prosthesis gradually migrated posterosuperiorly above the iliac crest, resulting in 14 cm of lower limb shortening. The acetabular reconstruction was performed using an allograft, and the middle segment of the tumor prosthesis was removed to allow for hip reduction. Concurrent reconstruction of the hip abductor muscles was also carried out. No recurrence of the dislocation was observed during follow-up, and the patient could walk independently with the aid of an orthopedic brace, despite an 8 cm leg length discrepancy.

Background: Cisplatin-based chemotherapy is a mainstay treatment for head and neck squamous cell carcinoma (HNSC); however, resistance to cisplatin contributes substantially to poor clinical outcomes. Identifying biomarkers associated with cisplatin response may improve prognostic assessment and treatment selection. Methods: We retrospectively analyzed The Cancer Genome Atlas (TCGA)-HNSC dataset to evaluate the association between microtubule associated scaffold protein 1 (MTUS1) expression and clinical outcomes, with particular emphasis on patients who were cisplatin-treated. Survival analysis was performed using the Kaplan-Meier curves, and differential expression analysis was conducted separately by comparing patients in disease-specific survival (DSS)-living and DSS-deceased groups. MTUS1 messenger RNA and protein levels were examined in cisplatin-sensitive oral cancer cell lines and their paired cisplatin-resistant counterparts using quantitative reverse transcription polymerase chain reaction and western blotting. Functional relevance was assessed by small interfering RNA-mediated MTUS1 knockdown in primary oral squamous cell carcinoma organoids. Results: MTUS1 protein expression was significantly lower in HNSC tumors than in non-tumor tissues. In the overall TCGA-HNSC cohort, MTUS1 expression was not significantly associated with survival. However, in patients who were cisplatin-treated, higher MTUS1 expression was significantly associated with more favorable DSS. MTUS1 expression was consistently lower in cisplatin-resistant oral cancer cell lines than in their paired cisplatin-sensitive counterparts. Functional experiments further suggested that reduced MTUS1 expression is associated with decreased cisplatin sensitivity and a resistant phenotype. Conclusion MTUS1 expression may be associated with clinical outcomes in patients with cisplatin-treated HNSC and is related to cisplatin responsiveness. These findings suggest a role for MTUS1 as a candidate treatment-relevant biomarker and highlight the value of integrating public omics data with experimental validation.

Purpose: Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing. Methods: A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs. Results: The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066). Conclusion Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.

Purpose: This study aimed to develop and implement an antimicrobial stewardship education program for physician assistant nurses and to evaluate its effects on their knowledge and clinical performance. Methods: A quasi-experimental, single-group pre-post design was conducted with 50 physician assistant nurses at a university hospital in Seoul, Republic of Korea. The antimicrobial stewardship education program, developed using the ADDIE model, consisted of 12 sessions including lectures and case-based learning (CBL)-based discussions.Knowledge was measured before and immediately after the intervention, while performance was assessed pre-intervention and four weeks post-program. Data were analyzed using paired t-tests, Wilcoxon signed-rank tests, and analysis of covariance (ANCOVA). Results: Knowledge scores significantly improved from 44.65±7.45 to 58.50±10.11 (p<.001), and all subdomains showed significant increases (p<.001). Performance scores increased from 3.68±0.77 to 4.28±0.68 (p<.001). Knowledge gain did not differ significantly between the medical and surgical departments (p=.710). Likewise, after adjusting for pre-test scores, no significant difference in performance improvement was observed between the two departments (ANCOVA, p=.170). These results indicate that the program was effective across both departments regardless of their characteristics. Conclusion The antimicrobial stewardship education program improved both knowledge and performance among physician assistant nurses. This program may contribute to the standardization of antimicrobial stewardship education and to appropriate antimicrobial use and the reduction of antimicrobial resistance.