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.

Sarcopenia is a major geriatric syndrome characterized by progressive loss of muscle mass and strength, resulting in disability and mortality. This narrative review synthesizes international consensus recommendations and Korean evidence to guide context-specific sarcopenia management strategies. PubMed, Embase, Cochrane Library, and KoreaMed (January 2000–November 2025) were searched, focusing on randomized trials, meta-analyses, systematic reviews, clinical practice guidelines, and large observational studies. Global diagnostic frameworks have evolved from muscle mass-based definitions toward multidimensional models that incorporate muscle strength and physical performance. Exercise and nutrition remain the mainstay treatments, with resistance-based training and adequate protein intake. Currently, pharmacologic options with proven clinical benefit are limited. In Korea, growing evidence supports the effectiveness of community-based sarcopenia interventions, underscoring the need for standardized, integrated delivery models that bridge the fragmented healthcare system and enable sustainable implementation.

Purpose: This study explored the experiences of physicians and nurses providing end-oflife care in Korean acute care hospitals. It aimed to identify the challenges faced in caring for dying patients and to suggest strategies for improving hospital-based end-of-life care. Methods: A qualitative exploratory design was employed using focus group interviews.Eleven healthcare professionals (five physicians and six nurses) working in tertiary or general hospitals participated in the study between July and August 2018. The interviews were conducted using a semi-structured guide covering seven thematic areas. All sessions were audio-recorded, transcribed verbatim, and analyzed thematically following Braun and Clarke’s framework. Results: Six major themes emerged: (1) communication with patients and families, (2) physical care for dying patients, (3) psychological and spiritual support, (4) hospital environment and system constraints, (5) moral distress and emotional burden on healthcare providers, and (6) suggestions for improvement. The participants described difficulties in open communication, limited resources for comfort care, emotional strain from invasive treatment at the end of life, and the absence of standardized institutional protocols.They emphasized the need for structured communication training, multidisciplinary collaboration, and integration of palliative care principles into acute care practice. Conclusion Physicians and nurses play a pivotal yet emotionally demanding role in providing end-oflife care in acute hospitals. Institutional reforms, including education, protocol development, and supportive environments, are essential to ensuring dignified, patient-centered care and sustain healthcare providers in their professional roles.

Purpose: This study aimed to develop and test a structural equation model of respiratory infection prevention behaviors among elementary school teachers based on the Information–Motivation–Behavioral Skills model. Methods: This study included 250 teachers who were currently working in elementary schools and had experience as homeroom teachers. Data were collected from December 18 to December 31, 2023 using self-reported questionnaires. The proposed model included school organizational culture as the exogenous variable and respiratory infection prevention knowledge, respiratory infection prevention attitude, social support, self-efficacy, and respiratory infection prevention behavior as endogenous variables. Data were analyzed using IBM SPSS for Windows ver. 24.0 and Smart PLS ver. 4.1. Results: Of the 19 hypothesized paths in the research model, five were statistically significant. School organizational culture had a significant direct effect on respiratory infection prevention knowledge (β=.20, p=.041), social support had a significant direct effect on self-efficacy (β=.33, p=.001), and self-efficacy had a significant direct effect on respiratory infection prevention behaviors (β=.22, p=.021). Respiratory infection prevention attitude (direct: β=.23, p=.029; total: β=.26, p=.008) and school organizational culture (direct: β=.22, p=.017; total: β=.30, p=.002) had significant direct and total effects on respiratory infection prevention behaviors. Conclusion To enhance respiratory infection prevention behaviors among elementary school teachers, interventions should focus on strengthening positive attitudes toward infection prevention and improving self-efficacy. Organizational-level strategies, including establishing supportive school organizational cultures, promoting peer support among teachers, and sharing infection prevention practices within schools, are also needed to facilitate and sustain preventive behaviors.

This review summarizes the establishment of the 2025 Dietary Reference Intakes for Koreans (KDRIs), the third national standard for nutrient reference values in Korea. The 2025KDRIs build on lessons from revisions in 2010, 2015, and 2020, and chart a path forward by addressing 4 priorities: upgrading the scientific evidence base through systematic evaluation, strengthening intake monitoring using national survey data, advancing international harmonization, and responding to changes in the nutrition and health environment, including those associated with the coronavirus disease 2019 (COVID-19) pandemic. The scientific basis of the KDRIs was advanced by systematically evaluating the findings across exposure indicators, health assessment indicators, and the health outcomes, and reorganizing the indicators to estimate the nutrient requirements. Adequate Intake was set using explicit criteria when an Estimated Average Requirement could not be derived, data gaps, uncertain outcomes, and limited representativeness were documented. Key inputs, including coefficients of variation and uncertainty factors, as well as life stage estimation procedures, were re-evaluated in alignment with current evidence and international standards. The 2025 KDRIs incorporate intake evidence from the Korea National Health and Nutrition Examination Survey to inform policy and practice and support intake monitoring. For international harmonization, the NUQUEST-based literature framework was updated, and recent DRIs from other countries were compared. The shifts in anthropometric characteristics and dietary intake patterns observed during the COVID-19 pandemic were considered to reflect a changing context. The review identified remaining challenges for future revisions, including validating Koreanspecific indicators, developing evidence for infants and older adults, stronger translation of reference values into policy and practice, prioritizing of nutrients for future review within the 5-year revision cycle. Together, these advances will position the 2025 KDRIs as a science-based national reference integrating policy, practice, and evidence to support implementation aimed at improving nutritional status and healthy life expectancy in Korea.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Background: This study aimed to investigate the effects of upper-extremity heat stress combined with resistance training and resistance training alone on body composition, skill and basal fitness, isokinetic muscle strength, and anabolic hormone levels in wheelchair rugby athletes with spinal cord injury. Methods: Fourteen male national wheelchair rugby athletes with cervical-level spinal cord injury were randomly assigned to the heat stress combined with resistance training (n=7) or resistance training group (n=7). Both groups completed a 10-week upper-extremity resistance training program. Additionally, heat stress was applied to the upper-extremity of the heat stress combined with resistance training group using steam-generating thermal sheets three times per week. Measurements conducted pre- and post-intervention included body composition, skill and basal fitness (one-hand throw, chest throw, 28 m shuttle sprint, and 20 m sprint), isokinetic strength (using the Cybex system at 60°/sec and 180°/sec), and anabolic hormones (growth hormone and insulin-like growth factor). Non-parametric tests (Wilcoxon signed-rank and Mann-Whitney U test) were used for statistical analysis (α=0.05). Results: The heat stress combined with resistance training group showed significant increases in skeletal muscle mass and upper-extremity isokinetic elbow joint strength, particularly in flexion (%BW) and extension (%BW) at 60°/sec. Growth hormone levels increased significantly only in this group, while insulin-like growth factor levels showed marginal improvement. Both groups improved in 28 m shuttle sprint and one-hand throw; however, the heat stress combined group showed a greater effect size in the 20 m sprint. No significant changes were observed in body mass index or body fat percentage. Conclusions The combination of heat stress and resistance training may provide additional benefits in enhancing upper-extremity muscle strength and stimulating anabolic hormone responses in wheelchair rugby athletes with spinal cord injury. These findings suggest a promising and practical strategy for optimizing training adaptations in this athletic population.

Objective: To evaluate the performance of supplemental automated breast ultrasound (ABUS) added to mammography-based breast cancer screening for women with nondense breasts. Materials and Methods: A retrospective search of radiology databases at two tertiary institutions identified asymptomatic women with nondense breasts who underwent breast cancer screening using both digital mammography (DM) and supplemental ABUS between January 2020 and December 2023. We excluded women without sufficient follow-up data or those without an established final diagnosis, including histopathologic results. The performance measures of DM alone and ABUS combined with DM (ABUS plus DM) were compared. The primary outcome was the cancer detection rate (CDR), and the secondary outcomes were sensitivity and specificity. Subgroup analyses were performed for women with scattered fibroglandular density and almost entirely fatty breasts. Results: A total of 2,904 pairs of screening examinations were performed in 1,683 women (59 ± 10 years), detecting 26 cancers. In comparison with DM alone, ABUS plus DM showed higher CDR (9.0 vs. 7.9 per 1,000 examinations, P < 0.001), higher sensitivity (100% [26/26] vs. 88.5% [23/26], P < 0.001), and lower specificity (95.0% [2,735/2,878] vs. 97.9% [2,817/2,878], P < 0.001). In women with scattered fibroglandular density, ABUS increased the CDR from 7.4 to 8.5 per 1,000 examinations and improved the sensitivity from 87.0% [20/23] to 100% [23/23] (P < 0.001). In women with almost entirely fatty breasts, ABUS plus DM showed the same CDR (16.4 per 1,000 examinations) and sensitivity (100% [3/3]) as DM alone. Three cancers (11.5% [3/26]), all of which were stage T1N0, were detected only by supplemental ABUS. Conclusion Supplemental ABUS improved cancer detection and sensitivity in women with nondense breasts, with the benefits primarily observed in those with scattered fibroglandular density.