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: As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea. Methods: A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC. Results: The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%). Conclusions Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.

Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

Background: The discovery and evaluation of reliable biomarkers of vitiligo are important;however, no clinically established serological markers exist for predicting the clinical prognosis of vitiligo. Objective: To investigate the levels of SOX10 and lamin A/C antibodies in the serum of patients diagnosed with vitiligo. Methods: In this multicenter prospective study, blood serum samples were collected from adult vitiligo patients. The levels of SOX10 and lamin A/C antibodies were analyzed by direct sandwich enzyme-linked immunosorbent assay. Antibody levels between the groups were compared according to disease activity and subtype. Results: A total of 80 patients (46 females; median age 60 years) were enrolled, including 56 (70%) with nonsegmental vitiligo and 27 (33.7%) with active disease. Positivity for SOX10 and lamin A/C antibodies was observed in 35.0% and 71.3% of patients, respectively. SOX10 positivity was significantly higher in active vitiligo than in stable vitiligo (59.3% vs. 24.5%; p=0.003), whereas lamin A/C positivity did not show significant difference (77.8% vs. 69.8%; p=0.60).No significant associations were found between SOX10 or lamin A/C status and the subtype, extent, or the presence of antinuclear antibody, anti-thyroid peroxidase, or anti-thyroglobulin (all p>0.05). Conclusion SOX10 antibody could be a potential marker for assessing disease activity in vitiligo. The increased production of SOX10 antibodies in the serum may be due to the underlying death or turnover of SOX10 containing cells under active autoimmune response.

Background: A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period. Methods: We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression. Results: Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated. Conclusion In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.

Buttock augmentation is an increasingly popular cosmetic procedure designed to enhance buttock contour, size, and shape. However, the safety profile of this procedure remains insufficiently established, and it carries risks of complications, including foreign body reactions and infections. These complications may be exacerbated by filler migration, resulting in large soft-tissue cavities that resemble pseudocysts. In this study, we describe two patients who developed severe complications following massive filler injections to the buttocks. A 56-year-old female patient presented with a 6×5 cm soft-tissue defect associated with an extensive underlying dead space, sinus tract formation, and a large pocket extending across the buttock. Additionally, a 50-year-old female patient developed diffuse cellulitis and multiple abscesses secondary to migration of an infected filler-related pseudocyst. Both patients underwent successful en bloc capsulectomy, resulting in marked clinical improvement without recurrence or postoperative complications. These cases underscore the serious complications associated with large-volume filler injections and highlight the importance of comprehensive surgical management in addressing late-stage adverse outcomes.

Skeletal muscle atrophy is a major complication associated with aging, chronic disease, and chemotherapy. Doxorubicin (Dox), a widely used anticancer agent, accelerates muscle wasting; however, the underlying cellular mechanisms remain poorly understood. In this study, we examined the effects of Dox on myogenic differentiation, senescence, and lipid metabolism using C2C12 myoblasts. Dox exposure impaired myotube formation without causing overt cytotoxicity. Mechanistically, Dox disrupted myogenic differentiation by inhibiting protein kinase B/mammalian target of rapamycin (AKT/mTOR) signaling, thereby de-repressing forkhead box O1/3 (FOXO1/3) and upregulating the muscle-specific ubiquitin ligases muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1), which promote proteolysis. Dox also decreased glycogen synthase kinase 3β (GSK3β) phosphorylation while paradoxically increasing total and phosphorylated β-catenin, indicating dysregulated Wnt/β-catenin signaling. These alterations were accompanied by a senescence-like phenotype, characterized by elevated senescence-associated β-galactosidase (SA-β-gal) activity, increased phosphorylated histone variant γH2AX, and activation of the p53–p21 axis. Notably, cellular senescence coincided with excessive lipid accumulation in myotubes. Dox reduced phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) while enhancing expression of key lipogenic regulators, thereby creating a metabolic environment favoring lipid storage. Collectively, these findings demonstrate that Dox not only suppresses myogenic differentiation but also induces premature senescence and metabolic reprogramming toward lipid accumulation. Targeting these pathways through AMPK activation, FOXO inhibition, or senolytic interventions may offer therapeutic strategies to preserve skeletal muscle integrity in patients undergoing chemotherapy.

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.

Purpose: There have been efforts to find alternative samples other than standard samples of tissue or plasma for mutational analyses for lung cancer patients. However, no other sample or technique has replaced the mutational analyses using standard samples. In this prospective study, we assessed a novel bronchoscopy method, named as targeted washing technique, for detecting the epidermal growth factor receptor (EGFR) mutation. Materials and Methods: A 3.0-mm ultrathin bronchoscope was precisely navigated to the target lung lesion with the assistance of virtual bronchoscopic navigation and fluoroscopy. Once the bronchoscope is placed in front of target lung lesion, 0.9% normal saline was instilled for targeted washing. EGFR testing using targeted washing fluid (TWF) was compared to standard methods using plasma or tumor tissue. Results: In 41 TWF samples, the T790M mutation was detected in tissue, plasma, and TWF samples at rates of 22.0%, 9.8%, and 29.3%, respectively. The overall EGFR T790M detection rate using tissue, plasma, or TWF samples was 36.6%, with TWF samples increasing the T790M mutation detection rate by up to 10%. The accuracy of T790M mutation detection using TWF sample was 82.9% compared with standard samples. Four patients were found to have the EGFR T790M mutation solely through EGFR testing using TWF, which repeated rebiopsies using either plasma or tissue finally confirmed to have the T790M mutation. Conclusion We demonstrated the clinical potential of targeted washing technique for molecular testing, which can be a good option to overcome spatial heterogeneity, low sensitivity of plasma sample or technical limitations in collecting tumor tissues.

Purpose: This study evaluates the Korean Cancer Study Group Geriatric Score-7 (KG-7) frailty screening tool’s effectiveness in elderly multiple myeloma (MM) patients to prevent under and overtreatment. Materials and Methods: This prospective pilot cohort study included 100 elderly patients aged 70 and older with newly diagnosed MM who had not undergone transplantation from August 2020 to January 2022. Results: The median age was 77 years, and 73.0% of patients were classified at International Staging System stages 2 or 3. Using a 5-point cutoff on the KG-7 index (non-frail, score ≥ 5; frail, score < 5), 31% were categorized as frail. After a median follow-up of 26.8 months, the 3-year overall survival rate was 73.0%. There was no statistically significant association between any frailty index and the risk of death. However, frail patients defined by the simplified frailty index (hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.09 to 5.95; p=0.030) and by KG-7 (HR, 2.43; 95% CI, 1.03 to 5.86; p=0.043) had a significantly higher risk of grade 3-4 non-hematologic toxicity, whereas the International Myeloma Working Group definition did not. Over a 24-month tracking period, vulnerability as measured by KG-7 either improved or deteriorated. Conclusion The pilot study, which had a limited number of participants, did not demonstrate KG-7’s effectiveness in predicting survival; however, it successfully predicted severe non-hematologic toxicities. We plan to conduct larger studies in elderly MM patients to determine whether KG-7 can help tailor their treatment regimens.