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: Persistent hypercalcemia after parathyroidectomy (PTx) remains a significant concern in patients with tertiary hyperparathyroidism (THPT) following kidney transplant (KT). Complete resection of hyperfunctioning glands is challenging due to ectopic or intrathyroidal glands. This study evaluated whether intraoperative parathyroid hormone (ioPTH) monitoring during PTx in KT patients with THPT reduces the surgical failure rate. Methods: We retrospectively analyzed 111 patients with THPT who underwent PTx at a single tertiary center. Patients were divided into 2 groups: those without ioPTH monitoring (n=98) and those with ioPTH monitoring (n=13). Surgical procedures included less than subtotal, subtotal, or total PTx with autotransplantation. Surgical failure was defined as persistent hypercalcemia (serum calcium ≥10.3 mg/dL and intact parathyroid hormone [PTH] >65 pg/mL) on postoperative day 1 (POD1) or at ≥6 months postoperatively. Results: The ioPTH group demonstrated a significantly lower mean PTH level on POD1 (21±15.3 pg/mL vs. 39±39 pg/mL; P=0.006). Although not statistically significant, the ioPTH group showed a higher biochemical cure rate at 3 months (53.8% vs. 30.6%) and no cases of persistent hyperparathyroidism, compared to 15.3% in the non-ioPTH group.Despite adequate intraoperative PTH reduction, some patients in both groups exhibited isolated PTH elevation without hypercalcemia. Conclusion Although ioPTH monitoring did not significantly reduce the surgical failure rate in PTx for THPT, the use of ioPTH may meaningfully improve surgical completeness and reduce the risk of persistent or recurrent hyperparathyroidism, suggesting its substantial potential value as an intraoperative.

Purpose: Hungry bone syndrome (HBS) is a common and critical postoperative complication in patients undergoing parathyroidectomy (PTX) for secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT). We aimed to identify clinical predictors of HBS and assess its impact on bone mineral density (BMD) after PTX. Methods: We retrospectively analyzed data of patients with SHPT and THPT who underwent PTX at Asan Medical Center (2010–2022). Clinical characteristics, including biochemical markers and BMD, were investigated. HBS was defined as profound hypocalcemia of less than 8.4 mg/dL (2.1 mmol/L) or prolonged hypocalcemia for more than 4 days after PTX. Results: A total of 91 patients were included: 18 (19.8%) with SHPT and 73 (80.2%) with THPT. Subtotal PTX was performed in 80 patients (87.9%), while 11 patients (12.1%) underwent total PTX with autotransplantation (TPTX + AT). HBS occurred in 31 patients (34.1%), with a higher incidence in patients with SHPT (72.2%) and all patients who underwent TPTX + AT.Patients with HBS required more calcium supplementation and had higher ALP levels at all timepoints (P < 0.001). In the HBS group, BMD improved more significantly in the femur (P = 0.005) and showed a trend towards improvement in the spine (P = 0.059). Risk factors for HBS included younger age, SHPT, and elevated preoperative ALP and intact parathyroid hormone levels. Conclusion HBS is characterized by severe hypocalcemia due to calcium reabsorption into bone after PTX. Identifying risk factors for HBS may promote early risk stratification and tailored perioperative management, including surgical approach, especially for high-risk patients.

The comprehensive in vitro proarrhythmia assay (CiPA) initiative, led by the U.S. Food and Drug Administration (FDA), provides a framework for predicting drug-induced arrhythmia risk. To support domestic CiPA implementation, we evaluated the proarrhythmic risk of sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor. Sildenafil has been misused recreationally, with reports of highdose non-medical intake. To simulate misuse, in vitro assays were conducted using concentrations up to 100× the maximum therapeutic plasma concentration (Cmax). The assessment followed the three core components of the CiPA paradigm. Patch clamp assays were conducted in Human Embryonic Kidney 293 (HEK293) and Chinese hamster ovary (CHO) cells transiently expressing Nav1.5, Cav1.2, and hERG ion channels. In silico modeling was performed using the CiPAORdv1.0 model based on IC₅₀ and Hill coefficient values. Functional evaluation included multi-electrode array (MEA) recordings in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and in vivo electrocardiography (ECG) analysis in rats was performed to observe QT interval prolongation. Sildenafil significantly inhibited hERG currents by 40.5% at 100× Cmax. In silico modeling predicted a low Torsades de Pointes (TdP) risk based on qNet biomarkers. In contrast, MEA recordings showed a concentration-dependent prolongation of corrected field potential duration (FPDc), with a significant 13.3% increase at 100× Cmax. The TdP risk estimated from MEA modeling was 64%. In vivo ECG analysis revealed significant QT prolongation at 50× Cmax. Despite low in silico TdP predictions, functional assays suggest that high concentrations of sildenafil as in misuse may pose a clinically relevant risk of QT prolongation and arrhythmia.

Objective: To classify life stages for companion dogs and cats by identifying clusters in age-specific disease proportions derived from medical records, providing a data-driven foundation for health examination programs. Methods: We collected 505,667 medical records from 82 veterinary facilities in South Korea between 2020 and 2023. Diagnoses were standardized using GPT-4o and S-BioBERT. Following preprocessing, data from 27 facilities yielded 222,706 canine and 39,910 feline records for the final analysis. Principal component analysis and K-means clustering (K = 4) were applied to age-specific disease proportions to identify life stages.The 10 most highest-proportion diagnoses diseases were determined for each cluster. Results: Canine life stages were classified as ≤ 1 year, 2–5 years, 6–10 years, and 11–15+ years.Feline life stages were 1–2 years, 3–8 years, 9–12 years, and 13–15+ years. In dogs, developmental diseases were common in the youngest age group, while chronic diseases were more prevalent in older groups. In cats, oral and urinary diseases were high-ranking, conjunctivitis was most common in the early stage, and chronic diseases increased with age. Conclusions and Relevance: Age-specific diagnosis patterns support four practical life stages for dogs and cats in South Korea. These boundaries can inform evidence-based preventive examination schedules, animal health policy, and pet insurance product design.

Purpose: Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN. Materials and Methods: Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods. Results: The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%). Conclusions EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.

Purpose: Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN. Materials and Methods: Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods. Results: The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%). Conclusions EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.

Purpose: Pediatric papillary thyroid cancer (PTC) is recommended to perform aggressive surgery to reduce the risk of recurrence.This study was designed to evaluate the concurrent association between multifocality, bilaterality, and the risk of recurrence in pediatric PTC. Materials and Methods: This retrospective cohort study included pediatric patients (age <19 years) who underwent total thyroidectomy for PTC between 1996 and 2014 in a single tertiary center. Clinicopathological parameters were analyzed to evaluate the prevalence of multifocality, bilaterality, recurrence, and their association. Results: We analyzed 58 pediatric patients with PTC. There was no factor related to the presence of multifocality or bilaterality in multivariate analysis. Also, in univariate analysis, multifocality and bilaterality were not independent risk factors of each other’s presentation (p=0.061 and p=0.061, respectively). Recurrence was observed in 19 (32.8%) patients. In multivariate analysis of recurrence, clear cell subtype, multifocality, and gross extrathyroidal extension (ETE) were independent risk factors (p=0.027, p=0.035, and p=0.038, respectively). Most recurrences (68.4%) happened during the first 4 years of follow-up after the initial thyroidectomy. Conclusion Multifocality and bilaterality were not independent risk factors of each other’s presentation; however, multifocality was the risk factor for recurrence in pediatric PTC. For pediatric PTC, close monitoring for recurrence within the initial 4 years is recommended, particularly in patients with clear cell subtype, multifocality, and gross ETE.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.