P-834. NO-CAP: Navigating Overdiagnosis of Community-Acquired Pneumonia in Hospitalized Patients

Low Incidence of Aerodigestive Cancers in Patients With Negative Results From Colonoscopies, Regardless of Findings From Multitarget Stool DNA Tests

Non-compliant Left Atrium Due to Scarring From Atrial Fibrillation Ablation Leads to Discordance of PAWP-LVEDP and Severe Post-Capillary Pulmonary Hypertension

e20522 Background: Tumor mutational burden (TMB) level is associated with response to immunotherapy in lung cancer. However, tissue TMB can be difficult to obtain, as tissue samples obtained from biopsies may be insufficient. Circulating tumor DNA-based TMB has been developed in order to complement or replace tissue TMB, but there is limited real-world data on their concordance. Here, we investigate the landscape and concordance between blood and tissue TMB, along with clinical traits of the concordant and discordant groups. Methods: Tumor mutational burden (TMB) was calculated using Tempus (tissue) and Guardant Health (blood) next generation sequencing (NGS) platforms from October 2020 to January 2021. There were 33 patients who had both Tempus and Guardant TMB data. Under the assumption that tissue TMB (tTMB) correlates with blood TMB (bTMB) at a ratio of 1:1.6, the patients were divided into concordant and discordant groups. The concordant group patients had bTMB/tTMB ratios between 1.3 and 1.9. The discordant group was divided into two subgroups: over 1.9 (Group B) and less than 1.3 (Group C). Among the 33 patients, 9 patients were excluded due to their non-evaluable bTMB levels. Treatment response was evaluated using RECIST criteria. Results: Of the remaining 24 patients, 7 patients in the concordant group and 21 patients in the discordant group were analyzed according to their clinical manifestations [Blood TMB (n = 24): range [1.46, 44.01], median = 9.57], [Tissue TMB (n = 24), range [1.3, 18.4], median = 4.5]. We compared the clinical presentations (number of metastatic organs and metastatic sites) between the two discordant groups (Groups B and C). Among the 24 patients, 13% (n = 3) had small cell lung cancer, 50% (n = 12) had adenocarcinoma, and 29% (n = 7) had squamous cell lung carcinoma. Patients with higher bTMB than tTMB (Group B) had more squamous cell carcinoma cases (71%, n = 5) compared to remaining groups (Groups A and C) (29%, n = 2). Among the discordant group, 6% of the patients (n = 1) had small cell lung cancer, 47% (n = 8) had adenocarcinoma, and 35% (n = 6) had squamous cell carcinoma. Further, 58% (n = 14) of the patients had higher bTMB than tTMB levels. Among the concordant and discordant groups, tumor burden as reflected by the number of metastatic sites and metastatic lesions and the sum of the largest diameters of tumor lesions using RECIST had no significant difference (p = 0.10, 0.68, 0.54, respectively). The concordant and discordant groups showed no significant difference in objective response (33% vs. 20%, p = 0.60) or clinical benefit rate (100% vs. 60%, p = 0.33). Conclusions: The majority of the patients had higher blood TMB than tissue TMB (Group A), with a concordance rate as low as 28%. Further studies are warranted to understand the biology behind the difference between blood and tissue TMB, including intertumoral heterogeneity.

Background: Breast cancer is a highly heterogeneous disease, and there is a biological diversity. Biological factors such as estrogen receptor, progesterone receptor, and HER2 receptor may vary between primary and metastatic sites in breast cancer. This variation could influence treatment responses in stage IV breast cancer. This exploratory analysis aims to differentiate drug efficacy and long-term prognosis between primary and metastatic sites in patients with de novo stage IV breast cancer. Methods: In JCOG1017, patients diagnosed with de novo stage IV breast cancer received primary systemic therapy (PST) according to subtypes after first registration. In this analysis, the efficacy of PST was evaluated prior to second registration (about 3 months post-initiation of systemic therapy), using both JCOG1017 criteria (progressive disease [PD] defined as a 10% or greater increase in long diameter) and additionally RECIST v1.1 criteria. In addition, the efficacy at about 6 months of PST in only patients with non-PD response at the second registration and assigned systemic therapy alone group was evaluated. Patients were categorized based on their treatment responses at primary versus metastatic sites into four groups: discordant group I (primary non-PD and metastatic PD), concordant group I (both primary and metastatic PD), discordant group II (primary PD and metastatic non-PD), and concordant group II (both primary and metastatic non-PD). We assessed clinicopathologic characteristics, including subtype of primary tumor and menopausal status, and overall survival (OS). Results: Of 570 patients who enrolled in JCOG1017, 315 patients were included in this analysis. In the evaluation at second registration using JCOG1017 criteria, the proportions of each group were 21.3% (67/315) for discordant group I, 8.3% (26/315) for concordant group I, 0.3% (1/315) for discordant group II, and 56.2% (177/315) for concordant group II. There were 14.0% (44/315) of patients with not evaluable. The overall discordance proportion of treatment effect between primary and metastatic sites was 25.1%. Subtype-specific discordance proportions were notably higher in luminal (28.9%) and triple-negative (25.0%) subtypes compared to HER2-enriched (11.1%). Menopausal status did not significantly impact discordance proportions (pre: 25.3% (24/95): post: 25.0% (44/176)). However, among the triple-negative subtype, the discordance proportion is much higher in the premenopausal population (45.5%:5/11) than in the postmenopausal population (7.7%:1/13). Median survival times were 3.8 years for discordant group I, 4.6 years for concordant group I, 1.7 years for discordant group II, and 5.7 years for concordant group II. No differences in prognosis were observed between discordant and concordant groups I. However, differences in prognosis between discordant and concordant groups II tended to be observed. The Kaplan-Meier curve for OS is similar based on both evaluation by JCOG1017 criteria and RECIST v1.1. Conclusions: We found a difference in the treatment efficacy of PST between primary and metastatic sites in the early phase of treatment for stage IV breast cancer, and most cases were primary non-PD and metastatic PD. In the early phase of PST for de novo stage IV breast cancer, not only primary tumors but also metastatic sites need to be examined. Citation Format: Kiyo Tanaka, Akihiko Shimomura, Makoto Ishitobi, Takashi Yamanaka, Takahiro Tsukioki, Hiroji Iwata, Fumikata Hara, Tomomi Fujisawa, Keita Sasaki, Ryo Sadachi, Riku Kajikawa, Takehiko Sakai, Yasuaki Sagara, Hideo Shigematsu, Yukinori Ozaki, Kazuki Nozawa, Kazuki Sudo, Yoichi Naito, Kaori Terada, Toshiyuki Ishiba, Haruhiko Fukuda, Tadahiko Shien. Differences in drug efficacy between primary and metastatic sites and their prognosis for de novo stage IV breast cancer: an exploratory analysis of a phase III trial, JCOG1017 [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P5-10-05.

Introduction: Guidelines have advocated use of scoring schemes such as CHADS 2 to assess stroke risk for patients with atrial fibrillation (AF). However, recent studies had demonstrated poor agreement between physician-reported and scoring-derived stroke risk. From a national registry, we assessed if rates of oral anticoagulant (OAC) use differ between patients whose stroke risks are concordantly or discordantly categorized. Methods: From December 2012 to July 2013, a cross-sectional analysis of 936 consecutive AF patients was performed, enrolled from 109 primary care and specialty practices in 10 Canadian provinces. Based on clinical judgment, physicians categorized each patient as low, moderate, or high risk for stroke. We categorized patients’ stroke risk based on their CHADS 2 score (low: 0; moderate: 1, high: ≥2). Agreement between physician-reported and CHADS 2 risk was reported by the weighted kappa. We compared rates of OAC use between patients whose stroke risk was concordantly or discordantly categorized by clinicians, relative to those derived from CHADS 2 . Results: Complete data were available in 929 (98.8%) patients for analysis. The weighted kappa between physician-reported and CHADS 2 -derived stroke risk was 0.41 (95% CI: 0.34 to 0.48). Physician-determined stroke risk was concordantly categorized to CHADS 2 scores in 544 (58.6%) patients. Among patients with CHADS 2 ≥2, rates of OAC use were similar between the concordant and discordant groups (91.7% vs. 90.4%, p=0.66). For patients with CHADS 2 =1, rates of OAC use were higher in the concordant group (84.2% vs. 66.4%, p<0.01). For patients with CHADS 2 =0, rates of OAC use were lower in the concordant group (43.5% vs. 80.0%, p<0.01). Conclusions: In this contemporary AF registry, the agreement between physician-reported and CHADS 2 -derived stroke risk was only modest. Despite this, the rate of OAC use in patients at high risk (CHADS 2 ≥2) was similarly high between the concordant and discordant groups. However, rates of OAC use between the 2 groups differed among patients at lower stroke risk. Our results suggest that discrepancy in stroke risk categorization is associated with guideline-discordant OAC use, particularly for patients with lower CHADS 2 scores.

Birth weight discordance and adverse neonatal outcomes in appropriately grown premature twins

Determination of appropriate operative methods for primary hyperparathyroidism (PHPT) is difficult when localisation results are discordant between imaging studies. The aim of this study was to compare the efficacy of focused parathyroidectomy (FP) and bilateral neck exploration (BNE) according to the concordance in localisation results. One hundred and ninety-one patients who underwent a PHPT operation at Asan Medical Center between 2000 and 2010 were divided into two groups according to the concordance in findings between neck ultrasonography (USG) and sestamibi (MIBI) scan. Differences in clinicopathological features and surgical outcomes between the concordant (n=137) and discordant (n=54) groups were analysed. FP and BNE did not show significant differences in postoperative persistent hyperparathyroidism rates. Although intraoperative parathyroid hormone (IOPTH) monitoring was not performed in this study, the cure rates of PHPT using only USG and MIBI scans were satisfactorily high, at 98.5% in the concordant group and 96.3% in the discordant group. The cure rates of FP and Unilateral exploration in single-negative USG and MIBI scans were 100%. Multiple lesions and hyperplasia were more common in the discordant group. In cases where it is difficult to apply IOPTH, FP without IOPTH is feasible in patients showing concordant or single-negative detection on USG and MIBI scans, whereas BNE is recommended in cases of discordance or double-negative results on imaging studies, to prevent recurrence or persistent disease. Appropriate selection of parathyroidectomy methods according to the concordance in USG and MIBI scans might produce good results without any difference in recurrence.

BackgroundThe emergence of antimicrobial resistance has complicated management of infections. We investigated whether empirical therapy discordant for chromosomal AmpC-Producing Enterobacterales (AmpC-E) had a clinical impact before switching to definitive therapy in pediatric urinary tract infections (UTIs).MethodsA retrospective study was conducted at Tokyo Metropolitan Children’s Medical Center from July 2010 to January 2024. Inclusion criteria were patients aged < 16 years with fever ≥ 38.0℃ and ≥ 10⁴ CFU/mL of AmpC-E in urine cultures. Exclusion criteria were pre-antibiotic defervescence, alternative diagnoses, or polymicrobial growth ( ≥ 3 species). Patients were classified into two groups. The discordant group received initial antibiotics considered ineffective for AmpC-E, such as penicillins or first to third generation cephalosporins. The concordant group received antibiotics generally recommended for AmpC-E, such as aminoglycosides or fourth generation cephalosporins or carbapenems. The primary outcome was time to defervescence. The secondary outcome was 30-day culture confirmed recurrence. Time to defervescence was analyzed by Kaplan–Meier curves.ResultsOf 135 cases identified, 76 met the inclusion criteria. The discordant and the concordant groups were 41 and 35, respectively. Median age was 6 months (IQR 4.8–16.8) in the discordant group and 8.4 months (IQR 4.8-33.6) in the concordant group. Common pathogens included Enterobacter cloacae (30%) and Klebsiella aerogenes (26%). Catheter-associated UTIs were 33%. Median time to defervescence was 16.9 hours (95% CI 5.8–28.0) in the discordant group and 20.5 hours (95% CI 17.1–23.9) in the concordant group, with no significant difference (p = 0.998) (Figure 1). 30-day culture confirmed recurrence occurred in one case each group.ConclusionIn pediatric UTIs caused by AmpC-E, initial discordant therapy was not associated with adverse clinical outcomes, suggesting that unnecessary use of broad-spectrum antibiotics may be avoided in empirical treatment.DisclosuresAll Authors: No reported disclosures

Intro: While thrombolysis in stroke mimics (SM) is considered safe, recent data highlights the excess cost associated with treatment of these patients. Several studies have identified common demographic features of SM, however less is known about whether language barriers between patient and physician influence SM treatment rates. We sought to evaluate the role of physician-patient language discordance on the rate of SM treatment at a single center serving a large Spanish-speaking population. Hypothesis: Stroke mimic treatment rates are higher when there are language barriers between physician and patient due to greater diagnostic uncertainty Methods: We reviewed the electronic medical record (EMR) for all patients who received tPA in the ED from 7/2011 to 7/2015. Patient’s primary language was obtained from the EMR; language fluency of treating neurologists was obtained via questionnaire; final diagnosis (SM, imaging negative, imaging confirmed) was the attending physician’s impression at discharge. We compared baseline characteristics and SM rates between encounters where the treating neurologist and patient spoke the same language (concordant group) versus those where they did not (discordant group). Means were compared via t test, medians via Mann Whitney U test and dichotomized variables via chi square test. Results: During this period 311 patients received tPA. English was the primary language for 158 (51%), Spanish for 144 (46%), and other languages for 9 (3%); 183 (59%) encounters were classified as concordant and 128 (41%) as discordant. Final diagnosis was SM for 37 (12%); among those with a final diagnosis of stroke, 65 (24%) were imaging negative. There were no significant differences in mean age (67 vs. 70, p=0.1), male sex (38% vs. 32%, p=0.3), and median NIHSS (7 vs. 7, p=0.4) between concordant and discordant groups. We found higher rates of SM in the concordant group (16% vs. 6%, p=0.01). When imaging negative strokes were included with SM, these differences were no longer significant (33% vs. 32%, p=0.9). Conclusion: At our institution, language discordancy does not contribute to higher rates of SM treatment. Careful observation of how language discordant pairs communicate is needed to understand the role of interpreters in these findings

Although endoscopic forceps biopsy is the gold standard for early gastric cancer (EGC) diagnosis, the method can cause endoscopic resection of specimens and histological discrepancies. This study aims to examine the risk factors for histological discrepancies in EGC and long-term clinical outcomes.This retrospective study included patients diagnosed with differentiated-type EGC using forceps biopsy. Patients without histological discrepancies and with undifferentiated types in endoscopic resection histology were categorized into the concordant and discordant groups, respectively. Clinical characteristics and long-term outcomes related to histological discrepancies were analyzed.A total of 957 lesions from 936 patients were enrolled. An overall discrepancy rate of 8.7% was confirmed, with an undifferentiated-type discrepancy of 5.5%. The discordant group showed a higher tendency for lesions to be located in the upper third region, to have whitish discoloration, and to undergo a greater number of biopsies compared with the concordant group. Multivariate analysis confirmed that lesion location in the upper third region (odds ratio [OR]: 2.125; 95% confidence interval [CI]: 1.032–5.277; P = .041) and whitish surface discoloration (OR: 13.615; 95% CI: 6.028–28.728; P = .001) were significantly correlated with histologic discrepancy. Compared with the concordant group, the discordant group had a lower curative resection rate, but no differences were observed in complications, local recurrence, or survival rates.Upper third location and whitish discoloration were risk factors for the histologic discrepancy between differentiated and undifferentiated types in patients with EGC. For curative resections performed in patients with EGC and histologic discrepancies and without additional treatment, careful follow-up is possible.

Abdominal ultrasound-guided transvaginal myometrial core needle biopsy for the definitive diagnosis of suspected adenomyosis in 1032 patients: a retrospective study.

Validity of the Global Vascular Guidelines in Predicting Outcomes Based on First-Time Revascularization Strategy

Introduction: Shorter door-to-needle time (DNT) is associated with better outcomes in acute ischemic stroke. Reducing door-to-CT time is a major focus of national quality improvement initiatives designed to reduce DNT, however time from CT-to-tPA administration has received far less attention. Recent data suggests that the CT-to-tPA interval contributes to significant delays in DNT. We hypothesized that language barriers between patients and treating neurologists would lead to longer CT-to-tPA times at a single stroke center serving a large Spanish-speaking population. Methods: We retrospectively reviewed the electronic medical record (EMR) on all patients who received IV-tPA in the emergency department over 2.5 years (July 2011 to December 2013). Patient’s primary language was obtained from the EMR; language fluency of treating neurologists was self-reported via standardized questionnaire. We compared baseline characteristics and relevant time intervals between encounters where the treating neurologist and patient spoke the same language (concordant group) versus those where they spoke a different language (discordant group). Means were compared with t-tests, medians with Mann-Whitney U tests, and dichotomized variables with Fisher exact tests. Results: A total of 199 patients received IV-tPA during the study period. English was the primary language for 110, Spanish for 83, and other languages for 6; of these, 120 cases were classified as concordant and 79 as discordant. There were no significant differences in mean age (67 vs. 69, p=0.3), male sex (37.5% vs. 24.1%, p=0.06), and median NIHSS (7 vs. 6, p=0.9) between concordant and discordant groups. We found no differences between median onset-to-arrival (68 vs. 71, p=0.3), door-to-CT (25 vs. 25, p=0.8), CT-to-tPA (33 vs. 29, p=0.2) and DNT (61 vs. 60, p=0.3) in minutes. There was a trend towards a greater proportion of patients with CT-to-tPA time under 30 minutes in the discordant group (52% vs. 38%, p=0.08). Conclusion: At our institution, language discordancy did not contribute to delays in CT-to-tPA nor overall DNT. CT-to-tPA time represents a largely unexplored contributor to overall delays in DNT that warrants further investigation.

Computed tomography (CT) and nuclear renography are used to determine kidney procurement in living kidney donors (LKDs). The present study investigated which modality better predicts kidney function after donation. This study included 835 LKDs and they were divided into two subgroups based on whether the left–right dominance of kidney volume was concordant with kidney function (concordant group) or not (discordant group). The predictive value for post-donation kidney function between the two imaging modalities was compared at 1 month, 6 months, and > 1 year in total cohort, concordant, and discordant groups. Split kidney function (SKF) measured by both modalities showed significant correlation with each other at baseline. SKFs of remaining kidney measured using both modalities before donation showed significant correlation with eGFR (estimated glomerular filtration rate) after donation in the total cohort group and two subgroups, respectively. CT volumetry was superior to nuclear renography for predicting post-donation kidney function in the total cohort group and both subgroups. In the discordant subgroup, a higher tendency of kidney function recovery was observed when kidney procurement was determined based on CT volumetry. In conclusion, CT volumetry is preferred when determining procurement strategy especially when discordance is found between the two imaging modalities.

The Fracture Risk Assessment Tool (FRAX) is used to calculate the 10-year probability of fracture using important clinical factors, with bone mineral density (BMD) as an optional input variable. We aimed to determine the rate of concordance between treatment recommendations of osteoporosis with 10-year probability of hip fracture calculated using FRAX scores with and without BMD and to identify relevant clinical risk factors associated with discordance. This was a cross-sectional study conducted in patients between 40 and 90 years of age who were screened for osteoporosis by BMD measurement using dual energy X-ray absorptiometry (DXA) from 2010 to 2018 at a university hospital in Thailand. A FRAX questionnaire was administered to determine demographic data and osteoporotic risk factors. FRAX scores with and without BMD were calculated for each participant using the Thai reference, and patients were categorized into either the treatment or non-treatment group based on a cut-off of 3% 10-year probability of hip fracture. When FRAX scores with and without BMD results were consistent, they were considered concordant. Otherwise, they were deemed discordant. Clinical risk factors were compared between the concordant and discordant groups. A total of 3545 participants were included in the study. The majority (83.8%) were in the concordant group. However, older age, lower BMD, and FRAX without BMD around the intervention threshold were significantly associated with discordant results. In the discordant group, FRAX with BMD suggested treatment in more participants with lower age, higher BMI, and lower BMD when compared with FRAX without BMD. FRAX scores with and without BMD yielded concordant predictions regarding the 10-year probability of hip fracture suggesting pharmacological treatment. However, this concordance declined in elderly and osteoporotic participants and in those with FRAX without BMD around intervention threshold. BMD data may be required in these populations in order to facilitate accurate risk assessment.