Citations

Abstract Introduction: Ewing sarcoma (EwS) is a FET::ETS family member-driven primary bone cancer demonstrating vast heterogeneity. Between a patient’s primary diagnosis and disease progression, tumor cell state adaptation, microenvironment changes, and the landscape of evolving therapeutic vulnerabilities remain poorly understood. To address these gaps, the Sean Karl Cohort was established in 2025 to conduct the largest single-cell transcriptomic analysis of retrospective paired tumor samples from patients with EwS. Here, we present data from the five analytic teams, and through shared SOPs now expand this cohort to Europe. Methods: Common sample processing SOPs were established to isolate cells from FFPE material from paired patient EwS samples. Single-cell (sc) RNAseq was generated using the GEM-X Flex Gene Expression protocol (10x Genomics). Alex’s Lemonade Stand Foundation (ALSF) Data Lab established a common data processing and integration pipeline with an EwS-specific cell annotation workflow to create a harmonized dataset for downstream analyses. Analytic teams were created to define tumor cell subpopulations and their therapeutic vulnerabilities and to characterize the tumor microenvironment. Data: We demonstrate the feasibility of generating high-quality scRNAseq profiles from retrospective FFPE-preserved EwS tumors. To date, 116 samples have yielded ∼800,000 cells. Integrated analysis reveals reproducible EwS tumor cell states shared across patients with regulatory network analyses nominating candidate therapeutic vulnerabilities. The scale of this international cohort enables saturation analysis for rare cell populations. Paired and longitudinal samples further allow correlation of emergent cell states with therapy resistance and metastatic progression. For example, immune-focused analyses show increases in T cell and macrophage populations in post-therapy samples. A novel, standardized EwS-specific cell annotation workflow has been developed to harmonize analyses and findings. These data will be openly shared with the community through the ALSF Single-cell Pediatric Cancer Atlas Portal. Conclusion: Large-scale international collaborative sample sharing, standardized processing pipelines, and harmonized EwS-specific annotations now enable deep single-cell analyses to characterize tumor heterogeneity in this rare pediatric and adolescent cancer. An in vivo expansion of the Sean Karl Cohort is underway to assess conservation of EwS tumor cell states and regulatory vulnerabilities identified in human tumors pre- and post-therapy in preclinical models, further supporting translation of these findings toward therapeutic strategies. Citation Format: Abbe Pannucci, Elina Mukherjee, Jessica D. Daley, Shireen Sita Ganapathi, Elissa Boguslawski, Lea Surrey, Lauren Gutstein, Patrick Azar, Emily Stockfisch, Azfar Neyaz, Ivy John, Jennifer Picarsic, Yutaro Tanaka, Byron Butaney, Riaz Gillani, Brian D. Crompton, Katherine A. Janeway, Jaclyln Taroni, Jessica Davis, Damon Reed, Adam Shlien, Theodore W. Laetsch, Rajen Mody, Clémence Henon, Thomas G. Grünewald, Elizabeth R. Lawlor, Filemon Dela Cruz, Patrick J. Grohar, Jovana Pavisic, Ally Hawkins, Anthony R. Cillo, Kelly M. Bailey. The Sean Karl Cohort: An international single-cell RNAseq study of paired patient Ewing sarcoma specimens [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 643.

Abstract Background The incidence of gastroesophageal cancer diagnosed at ages younger than 50 years is increasing. Assessment of the clinicopathologic and molecular characteristics of these cancers is limited currently. Methods This analysis used Tempus’ clinicogenomic database to compare patients diagnosed with gastroesophageal cancer at ages younger than 50 vs 50 years and older who completed tumor molecular profiling between December 2017 and July 2024. The spectrum of biomarkers, somatic alterations, and germline alterations were compared between those diagnosed with gastroesophageal cancer at ages younger than 50 years and those aged 50 years and older, and a multivariate analysis was conducted to identify factors associated with longer survival. Results Among 5863 gastroesophageal cancer patients, 785 had gastroesophageal cancer diagnosed at ages younger than 50 years. There were more females (35% vs 25%, P < .001) and fewer White patients (69% vs 80%, P < .001) with gastroesophageal cancer at ages younger than 50 years. Fewer tumors of patients with gastroesophageal cancer at ages younger than 50 years had high tumor mutational burden (3.2% vs 10.2%, P < .001) or high microsatellite instability (1.7% vs 5.1%, P < .001), but there was no difference in PD-L1 positivity (49% vs 51%, P = .3). Higher incidence of somatic CDH1 mutations was seen in those with gastroesophageal cancer at ages younger than 50 years (16.1% vs 6.6%, q < 0.001) with lower incidence of TP53 (65.6% vs 74.1%), CDKN2A (12.5% vs 19.8%), and KRAS (11.7% vs 18.3%, P < .001 for all) alterations. The most statistically significant germline difference was higher incidence of CDH1 (2.2% vs 0.3%, q = 0.001) and TP53 (0.6% vs 0%, q = 0.039) alterations among those with gastroesophageal cancer at ages younger than 50 years. Median survival for patients with metastatic disease was longer for gastroesophageal cancer at ages younger than 50 years (11 vs 8.5 months, P = .002), and gastroesophageal cancer at ages younger than 50 years, ERBB2 amplification, and high microsatellite instability were associated with superior survival. Conclusions Unique molecular and germline profiles were seen in patients with gastroesophageal cancer at ages younger than 50 years, which may suggest differences in causal factors yet undiscovered.

ABSTRACT The most common infectious disease responsible for paediatric developmental disability is congenital infection with human cytomegalovirus (cCMV). Many serious sequelae are caused by cCMV, including microcephaly, intracranial calcifications, neuronal migration defects, seizure disorders, developmental delay, and sensorineural hearing loss (SNHL). Although long‐term neurodevelopmental impairment is clearly more common in newborns with clinically apparent disease at birth, more knowledge is needed about management in the era of universal cCMV screening, since screening identifies infants that, in the past, would not have been discovered during routine newborn care—infants that we reference in this review as having clinically inapparent cCMV (CICMV) infections. For newborns identified with CICMV infections by universal cCMV screening, longitudinal audiologic assessment is needed, but other necessary laboratory and neuroimaging studies, as well as indications for antiviral therapy, are uncertain. This review summarises current concepts about the approach to cCMV infections identified by universal screening, with emphasis on the CICMV infant. We identify areas for future research that should inform and direct future evaluation and management of these infants.

ABSTRACT Electrocardiography (ECG) is a critical diagnostic tool for identifying cardiac conditions. While standard lead positions are widely used to ensure diagnostic accuracy, alternative lead placements have been developed to address specific clinical scenarios. These alternative configurations can overcome physical or technical challenges, enhance rhythm assessment, improve signal quality, and provide greater specificity for certain conditions, ultimately enabling more personalized diagnostic strategies. This paper examines the clinical significance of alternative ECG lead positions, highlighting their advantages, limitations, and potential applications in various clinical settings.

ABSTRACT Purpose Malignant rhabdoid tumor of the kidney (MRTK) is a rare, aggressive tumor seen in young children. The optimal timing of resection for locally advanced tumors is not well‐defined. The purpose of this study is to evaluate modern oncologic outcomes and the impact of surgical timing. Methods A multicenter retrospective review was performed by institutions participating in the Pediatric Surgical Oncology Research Collaborative. Children younger than 21 years old with MRTK diagnosed between 2000 and 2022 were included. Results Sixty‐nine patients were identified with MRTK and met the inclusion criteria. Median age of diagnosis was 10.1 months. Overall survival (OS) at 1, 5, and 10 years was 49%, 32%, and 19%, respectively. Patients with local Stage III disease who underwent upfront resection ( n = 18) compared to those who had delayed resection after NAT ( n = 15) had a similar OS, median OS greater than 60 months versus 14.6 months, respectively; p = 0.396. The surgical timing groups were balanced in terms of the presence of metastasis, length of follow‐up, and tumor characteristics. There was one occurrence of primary intraoperative tumor spill and two occurrences of organ injury in the upfront resection group compared to none in the delayed resection group. Conclusion MRTK carries a poor prognosis despite multimodal treatment. Histologic diagnosis may not be confirmed at presentation, and MRTK cannot be reliably distinguished from Wilms tumor on imaging alone. As overall survival is similar, the decision regarding surgical timing in locally advanced tumors should be individualized based on perceived resectability, balancing the risk of intraoperative complications against the possibility of tumor progression during neoadjuvant therapy.

BACKGROUND AND OBJECTIVES: The Congress of Neurological Surgeons (CNS) Leadership Institute developed the first structured leadership program designed specifically for neurosurgeons. Led by the experts in neurosurgery, health care administration, and business, the program provides formal leadership training and mentorship aimed at advancing neurosurgeons' professional development at local, regional, national, and international levels. METHODS: The CNS Leadership Institute offers 2 curricula tailored for junior and senior faculty. Training begins with assigned readings, webinars, and online lectures that establish essential leadership principles. Core learning occurs during 2 in-person courses featuring interactive lectures, feedback sessions, and a longitudinal leadership project guided by national mentors. Program outcomes were assessed through a 40-question survey of alumni evaluating training effectiveness, skill application, and career advancement. RESULTS: Since 2016, 195 neurosurgeons have completed the CNS Leadership Institute. Among the 77 survey respondents, 70.1% reported significant professional advancement (new leadership role or job transition), and 64.8% directly attributed their advancement in skills and insights acquired through the program. Overall program effectiveness was rated 4.4 of 5, and the mean likelihood-to-recommend was 8.95 (95% CI: 8.70-9.20), yielding a Net Promoter Score of +63 (95% CI: +49 to +77). Alumni have assumed prominent roles including 16 Residency Program Directors, 3 Department Chairs, 1 Vice Dean, 4 Service Line Leaders, 13 CNS Executive Committee members, and over 100 committee or editorial board appointments critical to the specialty. CONCLUSION: The CNS Leadership Institute equips neurosurgeons with structured leadership training, mentorship, and practical tools to enhance their effectiveness as leaders. Survey results confirm that the program has a measurable impact on participants' career trajectories and professional growth. This initiative provides a reproducible model for cultivating the next generation of neurosurgical leaders and advancing the specialty's capacity for strategic, transformational leadership.

Abstract Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults with a poor prognosis of 15 months despite aggressive therapies. GBM malignancy is often driven by a high degree of inter- and intra-tumoral heterogeneity that is dynamic through time and regulated by interactions between tumor cells and their neural microenvironment. For instance, GBM tumors located near the lateral ventricles (LV) of the brain grow more aggressively and result in significantly worse patient survival, compared to tumors that grow far from the LV. This suggests that interactions between GBM and cells in the LV microenvironment may regulate tumor malignancy. Understanding the mechanisms underlying GBM malignancy near the LV is essential to determine if regulation of tumor biology is driven by the presence of healthy neural cells, and to ultimately develop therapeutic approaches that target GBM-LV interactions. Here, we tested the hypothesis that region-specific cellular identities and activation of unique transcriptional programs regulate GBM malignancy near the LV. Paired primary biopsies were collected from 14 GBM patients. Image-guided biopsies proximal and distal to the brain’s LV (LV-proximal GBM and LV-distal GBM, respectively) were processed for bulk RNA sequencing, single-nucleus RNA sequencing, and in situ spatial transcriptomic (Xenium) analyses. We found significant inter-patient and intra-tumoral transcriptional heterogeneity in GBM samples collected proximal and distal to the LV. After accounting for tumoral and patient heterogeneity, we found that proximal GBM tumors exhibit an increased immune-related gene signature, compared with tumors distal to the LV. Single-nucleus RNA sequencing and in situ spatial transcriptomic analyses showed no significant differences in the proportion of cellular states or identities between proximal and distal GBM samples. However, within each cellular identity, significant differences in gene expression were identified between proximal and distal GBM, suggesting that distinct cell-specific transcriptional pathways characterize regional differences in GBM biology. Our results suggest that GBM tumors near the LV have increased interactions with immune cells that lead to the enrichment of immune-related transcriptional pathways, compared to tumors growing far from the LV. This work will inform the development of therapies that target GBM-immune cell interactions to decrease tumor malignancy and improve individual patient outcomes. Citation Format: Maria F. Gonzalez-Aponte, Jhan C. Salazar, Aura Figueroa-Gonzalez, Emily S. Norton, Paola Suarez-Meade, Hugo Guerrero-Cazares. Integrating RNA sequencing and spatial transcriptomic analyses reveals drivers of glioblastoma malignancy near the brains’ lateral ventricles [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Brain Cancer; 2026 Mar 23-25; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86(6_Suppl):Abstract nr B035.

Hospice and palliative medicine (HPM) simulation training primarily focuses on communication skills, rather than symptom management. Simulation can be an effective educational tool in high stakes clinical settings and provides a safe environment to improve skills in crisis management. HPM providers are often called to manage refractory symptoms in emotionally charged situations, especially at end-of-life care. These scenarios may present infrequently during their 1-year fellowship training. We describe a novel two-part simulation series ‘End of Life Symptom Management: Emergencies in Palliative Medicine’ that we have developed for our interdisciplinary HPM Fellowship. Our simulation series is conducted at our institution’s simulation centre and includes scenarios of (1) refractory pain, (2) palliative sedation, (3) initiation of buprenorphine-naloxone for cancer-associated pain in a patient with opioid use disorder (OUD), (4) acute pain crisis in a hospice patient with OUD on buprenorphine-naloxone, (5) terminal delirium, (6) compassionate extubation/respiratory distress, (7) status epilepticus and (8) terminal haemorrhage. Pre and postsession data collected from our HPM fellows reflect an increase in confidence levels after participating in the sessions. This simulation curriculum has allowed our fellows the opportunity to encounter and navigate these scenarios in a safe and controlled learning environment before encountering them in practice.