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.

Purpose: This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments. Methods: A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed. Results: Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities. Conclusion The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.

Purpose: This study aimed to investigate the effects of postnatal systemic corticosteroids on neurodevelopment in very low birth weight (VLBW) preterm infants. Methods: This was a population-based study of the Korean Neonatal Network of VLBW infant born at 23+0 and 31+6 weeks of gestation between 2013 and 2020. VLBW preterm infants assessed using the Bayley Scales of Infant and Toddler Development, third edition (BSID-III) at 18–24 months of corrected age and 3 years of age were enrolled. The primary outcomes were BSID-III scores and neurodevelopmental delays, with scores of <85. Socioeconomic status and clinical variables were adjusted for using multivariate regression analyses. Results: In total, 517 infants were enrolled in this study. Among the 216 (41.8%) infants who received postnatal systemic corticosteroids, the rate of cognitive delay was significantly higher at 18–24 months of corrected age than at 3 years of age. The rates of language and motor delays were significantly higher both at 18–24 months of corrected age and at 3 years of age. When multivariate logistic regression was performed, postnatal systemic corticosteroid use was significantly associated with cognitive delay at 18–24 months of corrected age, but not at 3 years of age. There was no significant association between postnatal systemic corticosteroid use and language or motor delay at 18-24 months of corrected age or at 3 years of age after multivariate logistic regression. Conclusion Postnatal systemic corticosteroid use in VLBW preterm infants increased the risk of cognitive delay at 18–24 months of corrected age, but not at 3 years.

Objective: Apnea in newborns is defined as a respiratory pause of 20 seconds or longer, or apnea accompanied by bradycardia or cyanosis. To date, research on neonatal apnea has focused on premature infants born within 34 weeks of gestation. The aim of this study is to present clinical significance of apnea in full-term infants compared with late premature infants born over 34 weeks of gestation. Methods: In a retrospective study, we reviewed medical records of neonates born over 34 weeks of gestation hospitalized for apnea and their mothers from November 2020 to May 2024. A total of 124 neonates were collected and divided into full-term infants (n=54) and late preterm infants (n=70) groups. Results: The mean gestational age of full-term and late preterm infants was 38 +5 weeks and 35 +2weeks, and the mean birth weight was 3.16 kg and 2.14 kg. Apnea was associated with diseases in 44.4% of full-term infants and 38.6% of late preterm infants. The rates of multiple births, small for gestational age, and cesarean section deliveries were significantly higher in late preterm infants.Apnea occurred significantly earlier and recovered faster in full-term infants. Neurologic disease was significantly more occurred in full-term infants (P=0.021). Especially, cerebral infarction and seizure were diagnosed only in full-term infants. Conclusion Apnea occurred earlier in full-term infants and severe neurologic diseases were significantly more found in full-term infants compared with late preterm infants. A close examination is needed in full-term infants with apnea.

Purpose: This study aimed to investigate the effects of postnatal systemic corticosteroids on neurodevelopment in very low birth weight (VLBW) preterm infants. Methods: This was a population-based study of the Korean Neonatal Network of VLBW infant born at 23+0 and 31+6 weeks of gestation between 2013 and 2020. VLBW preterm infants assessed using the Bayley Scales of Infant and Toddler Development, third edition (BSID-III) at 18–24 months of corrected age and 3 years of age were enrolled. The primary outcomes were BSID-III scores and neurodevelopmental delays, with scores of <85. Socioeconomic status and clinical variables were adjusted for using multivariate regression analyses. Results: In total, 517 infants were enrolled in this study. Among the 216 (41.8%) infants who received postnatal systemic corticosteroids, the rate of cognitive delay was significantly higher at 18–24 months of corrected age than at 3 years of age. The rates of language and motor delays were significantly higher both at 18–24 months of corrected age and at 3 years of age. When multivariate logistic regression was performed, postnatal systemic corticosteroid use was significantly associated with cognitive delay at 18–24 months of corrected age, but not at 3 years of age. There was no significant association between postnatal systemic corticosteroid use and language or motor delay at 18-24 months of corrected age or at 3 years of age after multivariate logistic regression. Conclusion Postnatal systemic corticosteroid use in VLBW preterm infants increased the risk of cognitive delay at 18–24 months of corrected age, but not at 3 years.

Objective: Apnea in newborns is defined as a respiratory pause of 20 seconds or longer, or apnea accompanied by bradycardia or cyanosis. To date, research on neonatal apnea has focused on premature infants born within 34 weeks of gestation. The aim of this study is to present clinical significance of apnea in full-term infants compared with late premature infants born over 34 weeks of gestation. Methods: In a retrospective study, we reviewed medical records of neonates born over 34 weeks of gestation hospitalized for apnea and their mothers from November 2020 to May 2024. A total of 124 neonates were collected and divided into full-term infants (n=54) and late preterm infants (n=70) groups. Results: The mean gestational age of full-term and late preterm infants was 38 +5 weeks and 35 +2weeks, and the mean birth weight was 3.16 kg and 2.14 kg. Apnea was associated with diseases in 44.4% of full-term infants and 38.6% of late preterm infants. The rates of multiple births, small for gestational age, and cesarean section deliveries were significantly higher in late preterm infants.Apnea occurred significantly earlier and recovered faster in full-term infants. Neurologic disease was significantly more occurred in full-term infants (P=0.021). Especially, cerebral infarction and seizure were diagnosed only in full-term infants. Conclusion Apnea occurred earlier in full-term infants and severe neurologic diseases were significantly more found in full-term infants compared with late preterm infants. A close examination is needed in full-term infants with apnea.

Purpose: This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments. Methods: A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed. Results: Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities. Conclusion The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.

Purpose: This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments. Methods: A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed. Results: Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities. Conclusion The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.

Purpose: This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments. Methods: A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed. Results: Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities. Conclusion The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.

Purpose: This study investigated the impact of nusinersen on health-related quality of life (HRQoL), functional performance, and caregiver burden in patients with infantile-onset spinal muscular atrophy (SMA), addressing a growing interest in disease-modifying treatments. Methods: A 14-month observational study was conducted to evaluate changes in HRQoL and functional performance using the Pediatric Quality of Life Inventory (PedsQL) Infant Scales and the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). Caregiver burden was assessed through the Assessment of Caregiver Experience with Neuromuscular Disease (ACEND). Motor function was evaluated using the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). Correlations between CHOP INTEND scores, functional performance, and caregiver burden were analyzed. Results: Eight patients with infantile-onset SMA and their caregivers participated, with a median treatment initiation age of 4.6 months (range, 1.1 to 15.1). CHOP INTEND scores showed significant improvement (P<0.001), whereas all PedsQL Infant Scale scores declined. Conversely, the PEDI-CAT revealed significant enhancements in daily activities, mobility, and social-cognitive domains (all P<0.001). Caregiver burden lessened across most dimensions (P<0.001), with the exception of the time-related burden (P=0.731). Higher CHOP INTEND scores correlated with improvements in PEDI-CAT domains and a reduction in caregiver burden related to sitting/play and transfer activities. Conclusion The study demonstrates the positive effects of nusinersen on functional performance and caregiver burden in patients with infantile-onset SMA. However, discrepancies were observed in HRQoL outcomes, suggesting a need for further research that includes SMA-specific outcome measures to comprehensively assess the treatment's impact on patients' lives.