Background: Impulse oscillometry (IOS) provides an effort-independent assessment of respiratory mechanics and is particularly sensitive to small airway dysfunction. Although IOS has been shown to complement spirometry in asthma, its association with exacerbation risk and its relationship with type 2 inflammatory biomarkers remain incompletely understood. Methods: In this retrospective cross-sectional study, 128 adult patients with physician-diagnosed asthma who underwent both spirometry and IOS at a tertiary hospital between January 2023 and July 2024 were analyzed. Exacerbation events during 1-year follow-up were identified from medical records. IOS parameters included resistance at 5 and 20 Hz (R5 and R20), reactance at 5 Hz (X5), resonant frequency (Fres), area under the reactance curve (AX), and frequency dependence of resistance between R5 and R20 (R5–R20). Correlations between spirometric indices and IOS parameters were assessed. Diagnostic performance for exacerbation events was evaluated using receiver operating characteristic (ROC) analysis. Exploratory analyses examined associations between IOS indices, fractional exhaled nitric oxide (FeNO), and blood eosinophil counts. Results: Thirty-three patients (25.8%) experienced exacerbations. AX showed the strongest correlations with forced expiratory volume in 1 second (FEV₁)% predicted (r=−0.51, p<0.001) and FEF25–75% predicted (r=−0.42, p<0.001). Patients with exacerbations exhibited significantly higher R5, Fres, AX, and R5–R20 compared with those without exacerbations, with AX demonstrating the largest effect size (Cohen’s d=0.91). In ROC analysis, AX showed the highest discriminative ability for exacerbation events (area under the curve=0.673). FeNO and blood eosinophil counts were not significantly correlated with IOS parameters and showed limited predictive performance when used alone; however, inclusion of AX significantly improved model discrimination. Conclusion IOS parameters, particularly AX, are significantly associated with asthma exacerbations and capture mechanical aspects of small airway dysfunction that are not fully reflected by spirometry or type 2 inflammatory biomarkers. IOS may provide clinically meaningful complementary information for risk stratification in asthma.

Purpose: While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer. Methods: Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses. Results: Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups. Conclusion This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.

Purpose: Lobular carcinoma In Situ (LCIS) is a noninvasive lesion associated with an increased risk of invasive cancer. Since its removal from the tumor, node, metastasis classification in the 8th edition of the American Joint Committee on Cancer (AJCC) guidelines, the clinical management of LCIS has shifted from surgery to surveillance. However, studies focusing on the risk and associated factors for invasive cancer development in pure LCIS without ductal carcinoma In Situ (DCIS) or invasive cancer remain limited. Methods: We retrospectively analyzed 106 patients diagnosed with pure LCIS between 2008 and 2018. This study evaluated the effect of tamoxifen use and histologic type on the development of invasive cancer. Results: All 106 patients underwent surgery, and nine (8.5%) developed invasive cancer over a median follow-up of 67.5 months. The incidence of invasive cancer was lower in the tamoxifen group (6.3%, n = 4) than in the non-tamoxifen group (11.9%, n = 5), although this difference was not statistically significant (p = 0.266). Pleomorphic LCIS had a significantly higher incidence of invasive cancer (30.0%, n = 3) than classic LCIS (6.3%, n = 6) (p = 0.045).Multivariable Cox regression analysis showed no significant difference in the risk of invasive cancer according to tamoxifen use (hazard ratio [HR], 2.031; 95% confidence interval [CI], 0.544–7.579; p = 0.292). However, pleomorphic LCIS showed a trend toward an increased risk of invasive cancer compared to classic LCIS (HR, 3.856; 95% CI, 0.922–16.126; p = 0.064). Conclusion Postoperative tamoxifen did not significantly lower invasive cancer development in patients with pure LCIS. Pleomorphic LCIS may carry a higher risk than classic LCIS. These findings require tailored follow-up and treatment strategies based on the histologic subtype of LCIS.

Purpose: This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control. Methods: We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR. Results: Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37). Conclusion Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.

Purpose: Finasteride and dutasteride are used to treat benign prostatic hyperplasia (BPH) and reduce the risk of developing prostate cancer. Finasteride blocks only the type 2 form of 5-alpha-reductase, whereas dutasteride blocks both type 1 and 2 forms of the enzyme. Previous studies suggest the possibility that dutasteride may be superior to finasteride in preventing prostate cancer. We directly compared the effects of finasteride and dutasteride on the risk of prostate cancer in patients with BPH using a pooled analysis of 15 real-world databases. Materials and Methods: We conducted a multicenter, cohort study of new-users of finasteride and dutasteride. We include patients who were prescribed 5 mg finasteride or dutasteride for the first time to treat BPH and had at least 180 days of prescription. We excluded patients with a history of prostate cancer or a prostate-specific antigen level ≥ 4 ng/mL before the study drug prescription. Cox regression analysis was performed to examine the hazard ratio (HR) for prostate cancer after propensity score (PS) matching. Results: A total of 8,284 patients of new-users of finasteride and 8,670 patients of new-users of dutasteride were included across the 15 databases. In the overall population, compared to dutasteride, finasteride was associated with a lower risk of prostate cancer in both on-treatment and intent-to-treat time-at-risk periods. After 1:1 PS matching, 4,897 patients using finasteride and 4,897 patients using dutasteride were enrolled in the present study. No significant differences were observed for risk of prostate cancer between finasteride and dutasteride both on-treatment (HR=0.66, 95% confidence interval [CI]: 0.44–1.00; p=0.051) and intent-to-treat time-at-risk periods (HR=0.87, 95% CI: 0.67–1.14; p=0.310). Conclusions Using real-world databases, the present study demonstrated that dutasteride was not associated with a lower risk of prostate cancer than finasteride in patients with BPH.

Background: Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD. Methods: This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests. Results: Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030). Conclusion This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.

Background: Strain elastography (SE) and shear wave elastography (SWE) are emerging techniques for evaluating the elasticity of soft tissue. This study aimed to determine interobserver and intraobserver reliability for elasticity measurements of different tissues and anatomic locations using SE and SWE. Methods: Ten healthy adult male individuals with 20 upper extremities participated in this study. The elasticities of the wrist extensor muscle, the common extensor tendon, and supraspinatus tendon were measured. Strain ratio and shear wave velocity were measured twice by 2 different examiners (examiner 1 with over 20 years of experience in musculoskeletal sonography and examiner 2 with 1 year of experience). Interobserver and intraobserver reliability was assessed using the intraclass correlation coefficient (ICC). Results: The 10 individuals’ age ranged from 28 to 35 years. In SE, interobserver reliabilities at the 3 anatomic locations (wrist extensor muscle, common extensor tendon, and supraspinatus tendon) showed fair to moderate agreement (ICC = 0.489, p = 0.076;ICC = 0.408, p = 0.131; and ICC = 0.296, p = 0.711, respectively). The intraobserver reliabilities of examiner 1 were moderate to substantial only at the wrist extensor muscle and the common extensor tendon (ICC = 0.563, p = 0.039 and ICC = 0.702, p = 0.006, respectively). In SWE, interobserver reliabilities for the wrist extensor muscle and the supraspinatus tendon were moderate to substantial (ICC = 0.756, p = 0.002 and ICC = 0.565, p = 0.039, respectively). The intraobserver reliabilities of examiner 1 at the 3 anatomic locations were almost perfect (ICC = 0.843, p = 0.001; ICC = 0.800, p = 0.001; and ICC = 0.825, p = 0.001, respectively).The results of examiner 2 showed almost perfect agreement at the wrist extensor muscle (ICC = 0.886, p = 0.001) and moderate to substantial agreement at the tendons of the common extensor and supraspinatus (ICC = 0.592, p = 0.029 and ICC = 0.682, p = 0.008, respectively). Conclusions SWE is a reliable method for assessing the flexibility of soft tissue, but it is affected by expertise and the specific anatomical site.

Background: Strain elastography (SE) and shear wave elastography (SWE) are emerging techniques for evaluating the elasticity of soft tissue. This study aimed to determine interobserver and intraobserver reliability for elasticity measurements of different tissues and anatomic locations using SE and SWE. Methods: Ten healthy adult male individuals with 20 upper extremities participated in this study. The elasticities of the wrist extensor muscle, the common extensor tendon, and supraspinatus tendon were measured. Strain ratio and shear wave velocity were measured twice by 2 different examiners (examiner 1 with over 20 years of experience in musculoskeletal sonography and examiner 2 with 1 year of experience). Interobserver and intraobserver reliability was assessed using the intraclass correlation coefficient (ICC). Results: The 10 individuals’ age ranged from 28 to 35 years. In SE, interobserver reliabilities at the 3 anatomic locations (wrist extensor muscle, common extensor tendon, and supraspinatus tendon) showed fair to moderate agreement (ICC = 0.489, p = 0.076;ICC = 0.408, p = 0.131; and ICC = 0.296, p = 0.711, respectively). The intraobserver reliabilities of examiner 1 were moderate to substantial only at the wrist extensor muscle and the common extensor tendon (ICC = 0.563, p = 0.039 and ICC = 0.702, p = 0.006, respectively). In SWE, interobserver reliabilities for the wrist extensor muscle and the supraspinatus tendon were moderate to substantial (ICC = 0.756, p = 0.002 and ICC = 0.565, p = 0.039, respectively). The intraobserver reliabilities of examiner 1 at the 3 anatomic locations were almost perfect (ICC = 0.843, p = 0.001; ICC = 0.800, p = 0.001; and ICC = 0.825, p = 0.001, respectively).The results of examiner 2 showed almost perfect agreement at the wrist extensor muscle (ICC = 0.886, p = 0.001) and moderate to substantial agreement at the tendons of the common extensor and supraspinatus (ICC = 0.592, p = 0.029 and ICC = 0.682, p = 0.008, respectively). Conclusions SWE is a reliable method for assessing the flexibility of soft tissue, but it is affected by expertise and the specific anatomical site.

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.