Citations

5073 Background: B7-H3 ( CD276 ) is an immunomodulatory protein overexpressed in prostate cancer (PC), representing a promising therapeutic target. However, expression of B7-H3 across PC disease states (hormone sensitive [HSPC], castration resistant [CRPC], neuroendocrine [NEPC]) and across races is poorly understood. We analyzed PC samples from a large clinico-genomic database to comprehensively characterize B7-H3 expression and elucidate its therapeutic potential in PC patients. Methods: We analyzed 7,682 PC samples with paired DNA/RNA profiling from Caris Life Sciences. Using CD276 mRNA expression measured by transcripts per million (TPM), samples were stratified into B7-H3-high (>75% centile) or low (<25% centile) groups. Annotations of HSPCs and CRPCs were based on time of biopsy collection relative to first use of androgen deprivation therapies. NEPC was defined histologically (Epstein, AJSP 2014). Transcriptomic alterations were compared using Mann-Whitney U tests. Overall survival (OS) was obtained from insurance claims data and assessed by Kaplan-Meier and Cox proportional hazards analyses. Results: B7-H3 was expressed at similar levels across specimen sites (prostate, lymph node, bone, liver, lung). HSPCs and CRPCs had similar levels of B7-H3 expression, but was reduced in NEPCs (TPM = 5.07, 4.96, 4.48; q<0.0001). While B7-H3-high was associated with worse OS in HSPCs (HR 1.32, 95CI 1.14-1.53, p=0.0002), it was associated with better OS in CRPC (HR 0.82, 95CI 0.69-0.97, p=0.018). B7-H3 expression was comparable in white, African American (AA), and Asian patients. However, Asian patients with high B7-H3 had worse outcomes (HR 4.08, 95CI 2.10-7.93, p<0.0001) while AA patients had improved outcomes (HR 0.74, 95CI 0.57-0.97, p=0.027). In co-expression analyses, B7-H3 was positively correlated with AR transcriptional co-factors ( HOXB13 , FOXA1 ) (R=0.59, 0.47; q<0.0001) but had weaker correlations with lineage plastic factors ( EZH2 , SOX2 , ASCL1 ) (R=0.26, 0.11, -0.02). Further, B7-H3-high correlated with high AR-score and low-NEPC. Given emergent bi-specific therapeutics in PC, we examined co-expression of B7-H3 with other cell surface targets. TROP2 ( TACSTD2 ) and NECTIN-4 ( PVRL4 ) exhibited the greatest correlation with B7-H3 (R=0.42, 0.40; q<0.0001); whereas PD-L1 ( CD274 ), CTLA4 , DLL3 , and CEACAM5 had weaker correlations (R=0.18, 0.08, 0.14, 0.09). Conclusions: High B7-H3 expression worsens prognosis in HSPC but improved prognosis in CRPC. Outcomes differed by race, with B7-H3-high Asian patients exhibiting worse OS while AA patients had better OS. The positive correlation between B7-H3 and AR co-factors suggests that B7-H3 is AR-regulated, at least in CRPC. Lastly, bi-specific approaches may be valuable against B7-H3-high tumors, with co-targeting of TROP2 and/or NECTIN-4.

9009 Background: International Medical Graduates (IMGs) are a vital component of the US oncology workforce, representing nearly half of practicing medical oncologists. However, systemic barriers may influence their career trajectories differently. Understanding these challenges is essential for addressing workforce disparities and optimizing cancer care delivery across diverse geographic regions. Methods: We conducted a cross-sectional study of 13,497 medical oncologists using the 2024 Dec CMS Provider Dataset linked with the 2023 Rural-Urban Continuum Codes (RUCC). Medical oncologists were identified by their self-reported primary specialties, including Hematology/Oncology, Medical Oncology, and Hematopoietic Cell Transplant. Physicians were categorized by graduation origin (based on their self-reported medical school), career stage (early: 0–10 years, mid: 11–30 years, late: >30 years post-medical school graduation). The primary outcomes included practice at Main Campus of NCI Designated Cancer Centers (as an indicator of academic practice) and the geographical location of their practice (Metro, Non-Metro, Mixed). We employed chi-squared tests for statistical comparisons and performed stratified analyses by career stage to evaluate transition patterns over time. Results: 6920 IMGs constituted 48.7% of the oncology workforce, with similar gender distributions between IMG and non-IMG oncologists (37.9% vs 36.5% female, p=0.068). Notably, early career oncologists were less likely to be IMGs (IMG vs non-IMGs: 8.2% vs 12.5%, p<0.001). Compared to Non-IMGs, IMG oncologists are less likely to practice at main campuses of NCI Center (19.9% vs. 27.7%, p<0.001), especially as their career advances (all p<0.01). (Table). IMGs had higher representation in non-metropolitan areas than non-IMGs (11.4% vs 9.1%, p<0.001), particularly in late-career stages (14.7% vs 12.3%, p=0.033), indicating their unique role in serving underserved regions. (Table). Conclusions: Our findings reveal that, IMGs are less likely to practice at main campuses of NCI-Cancer Center than their non-IMG colleagues. Meanwhile, IMG oncologists are disproportionately serving rural communities. Supporting IMG pathways in oncology is critical to ensure a balanced cancer care delivery across the United States. Practice setting distribution and academic affiliation among international medical graduates (IMGs) and US graduates (USGs) by career stage. IMG (N=6,577) Non-IMG (N=6,920) IMG (N=6,577) Non-IMG (N=6,920) NCI Center Other NCI Center Other Metro Non-Metro/Mixed Metro Non-Metro/Mixed Total 19.9% 80.1% 27.7% 72.3% 88.6% 11.4% 90.9% 9.1% Career Stage Early (0-10y) 29.1% 70.9% 36.1% 63.9% 91.1% 8.9% 95.4% 4.6% Mid (11-30y) 21.3% 78.7% 28.8% 71.2% 90.1% 9.9% 91.6% 8.4% Senior (30+y) 15.0% 85.0% 22.0% 78.0% 85.3% 14.7% 87.7% 12.3%

Importance Nontraumatic subarachnoid hemorrhage (SAH) represents the third most common stroke type with unique etiologies, risk factors, diagnostics, and treatments. Nevertheless, epidemiological studies often cluster SAH with other stroke types leaving its distinct burden estimates obscure. Objective To estimate the worldwide burden of SAH. Design, Setting, and Participants Based on the repeated cross-sectional Global Burden of Disease (GBD) 2021 study, the global burden of SAH in 1990 to 2021 was estimated. Moreover, the SAH burden was compared with other diseases, and its associations with 14 individual risk factors were investigated with available data in the GBD 2021 study. The GBD study included the burden estimates of nontraumatic SAH among all ages in 204 countries and territories between 1990 and 2021. Exposures SAH and 14 modifiable risk factors. Main Outcomes and Measures Absolute numbers and age-standardized rates with 95% uncertainty intervals (UIs) of SAH incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) as well as risk factor–specific population attributable fractions (PAFs). Results In 2021, the global age-standardized SAH incidence was 8.3 (95% UI, 7.3-9.5), prevalence was 92.2 (95% UI, 84.1-100.6), mortality was 4.2 (95% UI, 3.7-4.8), and DALY rate was 125.2 (95% UI, 110.5-142.6) per 100 000 people. The highest burden estimates were found in Latin America, the Caribbean, Oceania, and high-income Asia Pacific. Although the absolute number of SAH cases increased, especially in regions with a low sociodemographic index, all age-standardized burden rates decreased between 1990 and 2021: the incidence by 28.8% (95% UI, 25.7%-31.6%), prevalence by 16.1% (95% UI, 14.8%-17.7%), mortality by 56.1% (95% UI, 40.7%-64.3%), and DALY rate by 54.6% (95% UI, 42.8%-61.9%). Of 300 diseases, SAH ranked as the 36th most common cause of death and 59th most common cause of DALY in the world. Of all worldwide SAH-related DALYs, 71.6% (95% UI, 63.8%-78.6%) were associated with the 14 modeled risk factors of which high systolic blood pressure (population attributable fraction [PAF] = 51.6%; 95% UI, 38.0%-62.6%) and smoking (PAF = 14.4%; 95% UI, 12.4%-16.5%) had the highest attribution. Conclusions and Relevance Although the global age-standardized burden rates of SAH more than halved over the last 3 decades, SAH remained one of the most common cardiovascular and neurological causes of death and disabilities in the world, with increasing absolute case numbers. These findings suggest evidence for the potential health benefits of proactive public health planning and resource allocation toward the prevention of SAH.

Abstract The complementarity and clinical utility of combining liquid biopsies and radiomic image analysis has not been demonstrated. ctDNA minimal residual disease after chemoradiotherapy (CRT) for non–small cell lung cancer (NSCLC) is highly prognostic, but on-treatment biomarkers are needed to enable response-adapted therapies. In this study, we analyzed 418 patients with NSCLC undergoing CRT to develop and validate a novel dynamic risk model that accurately predicts ultimate progression-free survival during treatment. We optimize tissue-free variant calling from plasma samples to facilitate ctDNA monitoring and demonstrate the importance of accounting for persistent clonal hematopoiesis variants. We show that mid-CRT ctDNA concentration is prognostic for disease progression and integrate additional pre-CRT risk factors, including radiomics, into a combined model that improves outcome prediction. Our results suggest that tumor features, radiomics, and mid-CRT ctDNA analysis are complementary and can identify patients at high and low risk of progression to potentially enable response-adapted therapies. Significance: This study demonstrates that combining tumor features, radiomics, and ctDNA analysis improves outcome prediction in NSCLC treated with CRT therapy. Our integrated model could enable personalized and response-adapted therapies to reduce toxicity and improve outcomes in patients. See related commentary by Anagnostou and Aggarwal, p. 1534

Abstract Oncogenic translocations involving the MET gene have been reported in several cancer types, but detailed clinicogenomic characterization of these cancers is not well defined. In addition, prospective clinical trials evaluating the antitumor activity of MET inhibitors in MET rearrangement–positive cancers are limited. In this study, in a pan-cancer analysis of &gt;46,000 solid tumors with comprehensive genomic profiling, we identified oncogenic MET rearrangements in ∼0.04% of cancers. Preliminary analysis from a phase II clinical trial of the type I MET tyrosine kinase inhibitor (TKI) vebreltinib in MET fusion–positive solid tumors demonstrated an objective response rate of 50% and disease control rate of 79%, with antitumor activity seen in diverse cancer types, including lung adenocarcinoma and intrahepatic cholangiocarcinoma, among others. Similar to MET exon 14–altered lung cancer, secondary mutations in the kinase domain can confer resistance to MET TKIs in MET fusion–positive cancers. Overall, these data categorize MET rearrangements as actionable targets in solid tumors. Significance: MET rearrangement–positive cancers are not well-characterized, and optimal treatment strategies are yet to be defined. Through comprehensive genomic analysis, preclinical modeling, and preliminary results of a phase II clinical trial, we demonstrate that MET fusions are a unique molecular subtype of cancers targetable with vebreltinib, a TKI in development.