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 aimed to report the real-world outcomes of intravesical gemcitabine for bacillus Calmette–Guérin (BCG)–unresponsive, high-risk, non–muscle-invasive bladder cancer (HR-NMIBC) in Korean patients who were unable or unwilling to undergo radical cystectomy (RC). Materials and Methods: This retrospective study included 131 patients (median age, 69 years; 88.5% men) treated with intravesical gemcitabine for BCG-unresponsive HR-NMIBC at nine centers between May 2019 and April 2022. The primary endpoint was 1-year recurrence-free survival (RFS). The secondary endpoints included factors influencing RFS, progression-free survival (PFS), cystectomy- free survival, cancer-specific survival (CSS), overall survival (OS), and safety. Survival analysis was performed using the Kaplan-Meier method, and risk factors for recurrence were assessed using Cox regression models. Results: Patients were followed up for a median duration of 25 months, with carcinoma in situ (CIS) in 41.9% of the patients. The 1-year and 2-year RFS rates were 68% and 42%, while the 1-year and 2-year PFS rates were 87% and 77%, respectively. No significant factors influencing RFS were identified. Seventeen patients underwent RC during a median follow-up of 16 months, with the condition in three patients progressing to muscle-invasive disease on final pathological analysis. The 2-year CSS and OS rates were 98% and 97%, respectively. Intravesical gemcitabine was well-tolerated, with only seven patients (5.3%) unable to complete the full induction course. Conclusion Our research highlights the potential of intravesical gemcitabine as a viable bladder-sparing treatment option for BCG-unresponsive HR-NMIBC, providing real-world evidence on its safety, efficacy, and tolerability.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Background: Hypercalcemia of malignancy (HCM), a major metabolic complication of cancer, is often managed with bisphosphonates (BP) and, increasingly, with denosumab. We aimed to compare the effectiveness and safety of denosumab with that of BP, with or without calcitonin, in treating HCM. Methods: This retrospective cohort study was conducted at a tertiary hospital from 2017 to 2022 and included 317 patients treated for HCM. Participants were divided into three treatment groups: denosumab, intravenous (IV) BP only, and IV BP combined with calcitonin. The primary outcomes measured were changes in calcium levels and the incidence of hypocalcemia. Analysis of covariance was used to adjust for age, sex, body mass index, creatinine level, type of malignancy, and the use of furosemide and steroids. Results: The mean participant age was 65 years, and 37.5% were female. After adjustment, both denosumab and IV BPs were found to effectively lower calcium levels. Denosumab led to a decrease of 2.0 mg/dL (−15.9%), while IV BP alone resulted in a reduction of 1.8 mg/dL (−13.9%). The largest reduction, of 2.7 mg/dL (−20.9%), occurred with IV BP and calcitonin. Both denosumab and IV BP+calcitonin yielded their lowest calcium levels within 48 hours, whereas the IV BP only group reached a nadir within 72 hours. Despite these differences in treatment effectiveness, hypocalcemia occurred significantly less frequently in the denosumab group compared to the other groups. Conclusion Denosumab and IV BP were similarly effective in reducing calcium levels. However, IV BP combined with calcitonin yielded a more rapid and pronounced decrease.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Background: Hypercalcemia of malignancy (HCM), a major metabolic complication of cancer, is often managed with bisphosphonates (BP) and, increasingly, with denosumab. We aimed to compare the effectiveness and safety of denosumab with that of BP, with or without calcitonin, in treating HCM. Methods: This retrospective cohort study was conducted at a tertiary hospital from 2017 to 2022 and included 317 patients treated for HCM. Participants were divided into three treatment groups: denosumab, intravenous (IV) BP only, and IV BP combined with calcitonin. The primary outcomes measured were changes in calcium levels and the incidence of hypocalcemia. Analysis of covariance was used to adjust for age, sex, body mass index, creatinine level, type of malignancy, and the use of furosemide and steroids. Results: The mean participant age was 65 years, and 37.5% were female. After adjustment, both denosumab and IV BPs were found to effectively lower calcium levels. Denosumab led to a decrease of 2.0 mg/dL (−15.9%), while IV BP alone resulted in a reduction of 1.8 mg/dL (−13.9%). The largest reduction, of 2.7 mg/dL (−20.9%), occurred with IV BP and calcitonin. Both denosumab and IV BP+calcitonin yielded their lowest calcium levels within 48 hours, whereas the IV BP only group reached a nadir within 72 hours. Despite these differences in treatment effectiveness, hypocalcemia occurred significantly less frequently in the denosumab group compared to the other groups. Conclusion Denosumab and IV BP were similarly effective in reducing calcium levels. However, IV BP combined with calcitonin yielded a more rapid and pronounced decrease.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Background: Hypercalcemia of malignancy (HCM), a major metabolic complication of cancer, is often managed with bisphosphonates (BP) and, increasingly, with denosumab. We aimed to compare the effectiveness and safety of denosumab with that of BP, with or without calcitonin, in treating HCM. Methods: This retrospective cohort study was conducted at a tertiary hospital from 2017 to 2022 and included 317 patients treated for HCM. Participants were divided into three treatment groups: denosumab, intravenous (IV) BP only, and IV BP combined with calcitonin. The primary outcomes measured were changes in calcium levels and the incidence of hypocalcemia. Analysis of covariance was used to adjust for age, sex, body mass index, creatinine level, type of malignancy, and the use of furosemide and steroids. Results: The mean participant age was 65 years, and 37.5% were female. After adjustment, both denosumab and IV BPs were found to effectively lower calcium levels. Denosumab led to a decrease of 2.0 mg/dL (−15.9%), while IV BP alone resulted in a reduction of 1.8 mg/dL (−13.9%). The largest reduction, of 2.7 mg/dL (−20.9%), occurred with IV BP and calcitonin. Both denosumab and IV BP+calcitonin yielded their lowest calcium levels within 48 hours, whereas the IV BP only group reached a nadir within 72 hours. Despite these differences in treatment effectiveness, hypocalcemia occurred significantly less frequently in the denosumab group compared to the other groups. Conclusion Denosumab and IV BP were similarly effective in reducing calcium levels. However, IV BP combined with calcitonin yielded a more rapid and pronounced decrease.