Citations

ABSTRACT Introduction It is controversial whether surgical correction of tethered spinal cord in non‐myelomeningocele tethered cord patients results in reversal versus stabilization of urologic (GU), gastrointestinal (GI), and musculoskeletal (MSK) symptoms. Objective To determine factors associated with clinical improvement in symptoms after spinal cord de‐tethering, and evaluate whether pre‐operative urodynamic testing predicts post‐operative clinical outcomes. Methods 213 non‐myelomeningocele children who underwent primary spinal cord de‐tethering at a quaternary children's hospital from 2012 to 2020 were retrospectively reviewed. Age at surgery, gender, and presence of GU symptoms, constipation, MSK symptoms, and urodynamic studies were collected. Pre‐operative symptoms and demographics were compared between patients with and without resolution of GU symptoms after surgery. Results Mean age at surgery was 5.36 years, 48% were female, and mean length of follow up was 1.8 years. Before surgery, 133/213 (62%) experienced a GU symptom. 105/213 (49%) patients were potty‐trained. Of 105 potty‐trained patients, 50 (48%) had daytime incontinence and 55 (52%) had nocturnal enuresis. Of 88 potty‐trained patients with urinary symptoms, 22 (25%) had resolution of and 59 (67%) had improvement following surgery. Of the 102 with constipation, 45 (44%) had improvement. Of the 116 with musculoskeletal symptoms, 60 (52%) had improvement. Patients with resolution of GU symptoms were younger (4.97 vs. 8 years, p = 0.0019). Patients with daytime urinary incontinence ( p = 0.0119) were less likely to have resolution of GU symptoms. There was no difference in urodynamic findings between patients with and without improvement or resolution of urologic symptoms. Conclusion Younger age at de‐tethering surgery is associated with improvement in genitourinary symptoms. Preoperative urodynamic studies may not be predictive of postoperative outcomes.

Abstract Introduction The evaluation of diastolic function in diabesity patients undergoing incretin-based therapy could facilitate early detection and help prevent progression to heart failure. Methodology A group of 15 diabesity cases with chest x-ray examinations (< 1 month) before and after ≥ 12 months of incretin-based therapy (absent ventricular/valvular dysfunction) were identified. Standard diabesity descriptors and predictions of pulmonary venous hypertension (aka “pulmonary congestion”) [None; Stage 1: vascular distention/redistribution but minimal interstitial edema; or Stage ≥ 2: vascular congestion with ≥ mild interstitial or alveolar edema] by validated AI-enabled chest x-ray staging, representing mean left atrial pressure in diastolic dysfunction, were evaluated pre- and post-therapy. Results By weight loss, cases clustered into equal-sized subgroups: 1. Significant Responders (9–30% decreases); 2. Insignificant Responders (0–2% decreases); and 3. Non-Responders (2–12% increases). Regarding hemoglobin A1c changes: 1. Significant Responders collectively decreased; 2. Insignificant Responders varied; and 3. Non-Responders were largely stable. Pre-therapy, all 15 cases demonstrated AI-enabled chest x-ray evidence of diastolic dysfunction; post-therapy, 4 improved (especially cases of greatest weight loss or hemoglobin A1c reduction), 5 were stable, and 6 worsened. Per subgroup, AI-enabled chest x-ray indications therapeutic response were: 1. Significant Responders (all demonstrating unequivocally decreased obesity and improved diabetes) collectively showed stable-decreased dysfunction; 2. Insignificant Responders (all demonstrating minimally decreased obesity but stable-worsening diabetes in most) reflected stable-increased dysfunction in 60%; and 3. Non-Responders (all demonstrating increased obesity but stable-improved diabetes) showed increased dysfunction in 80%. Conclusion AI-enabled CXR staging detects background subclinical diastolic dysfunction in diabesity and monitors its response to incretin-based therapy.

Abstract Gastrointestinal (GI) cancers are rising in people &lt; 50 and remain major causes of cancer mortality despite therapeutic advances. Chimeric antigen receptor T (CART) cell therapy has transformed treatment of hematological cancers. However, its efficacy in GI cancers has been hindered by antigen heterogeneity and immunosuppressive cancer associated fibroblasts (CAFs) in the tumor microenvironment (TME.) Here we aimed to 1) study CART-CAF interactions and 2) engineer CART cells capable of eliminating CAFs to overcome their inhibitory role and enhance their antitumor activity in GI cancers. We first analyzed primary CAFs from 20 GI cancer patients. CAFs showed high fibroblast activation protein (FAP) expression and significantly suppressed T cells proliferation (26-77%, p≤0.0001). We next generated CART cells capable of safely eliminating both GI cancer cells and CAFs. To target cancer cells, we developed a novel nanobody (VHH)-based CAR against Claudin18.2, a GI cancer specific target. To avoid off-tumor toxicity in healthy FAP+ tissues, we incorporated an inducible FAP-CAR using the synNotch platform, enabling conditional targeting upon engagement with Claudin18.2+ cells, restricting FAP targeting within the TME. VHH Claudin18.2 CART cells showed superior specificity and efficacy vs scFv-based CART cells (hu8E85 or zolbetuximab). In Claudin18.2+ SNU-C2B xenografts, tumors were 92mm3 (VHH) vs 48mm3 (huE85) vs 211mm3 (zolbetuximab) on day 23 post-CART, median survival undefined vs 17 days vs 23 days respectively; p=0005. In Claudin18.2+ LS411N xenografts, tumors were 315mm3 vs 106mm3 vs 382 mm3 respectively at 23 days post-CART, median survival undefined vs 19 days vs undefined respectively; p=0004. VHH Claudin18.2 CART cells showed no off-tumor effects, while hu8E85 CART induced significant toxicity. We next established a co-engraftment model. NSG mice received 1x106 SNU-C2B and 6x106 CAFs from a GI cancer patient. At 500 mm3 tumors, mice received 5x106 VHH Claudin18.2 or inducible Claudin18.2/FAP CART. Dual-targeting CART cells showed greater antitumor response (728mm3 vs 320mm3, p=0.0011 at day 20 post-CART), expansion (61 vs 2,350 CART/µl of blood, p=0.0037), and tumor infiltration (8.71 x 105 vs 1.03 x 106 CART/g of tumor, p&lt;0.0001). This was also observed in gastric, colon, and pancreatic PDX models, with no observable off-tumor cytotoxic effects with inducible dual-targeting Claudin18.2/FAP CART. Our findings demonstrate that our novel VHH-based Claudin18.2 CART cells are highly specific and effective against GI malignancies, and that inducible Claudin18.2/FAP dual-targeting CART cells safely remodel the TME into an immune-permissive state. This approach represents a mechanistically innovative and translationally relevant strategy to overcome CAF-mediated immunosuppression, enhance CART cell efficacy, and improve clinical outcomes in refractory solid tumors. Citation Format: Omar L. Gutierrez Ruiz, Jennifer Feigin, Brooke Kimball, R. Leo Sakemura, Elizabeth L. Siegler, Dominic A. Skeele, Ateka Saleh, Claudia Manriquez Roman, Ismail Can, Olivia Sirpilla, Kun Yun, Carli M. Stewart, Mehrdad Hefazi, Yoh Yamaguchi, Lionel Aurelien Kankeu Fonkoua, Long K. Mai, Truc Huynh, Sophia Y. Goldberg, Grace E. DeFranco, Sara Foote, Ekene Johnkennedy Newton Ogbodo, Hong Xia, Michael Redig, Matthew L. Matthew, Tamiel Nichole Turley, Skyeler Klinge, John Alton Copland, Saad J. Kenderian. Optimized CART cell therapy to remodel the tumor microenvironment and eliminate GI malignancies [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 1525.

Abstract Background: Endometrial cancer (EC) remains a major gynecologic malignancy driven in part by aberrant estrogen receptor (ER) signaling. The active tamoxifen metabolite (Z)-endoxifen exhibits dual SERM/SERD-like activity, modulating ER function while exerting additional noncanonical antiproliferative effects. Understanding (Z)-endoxifen’s mechanisms of action and its interaction with cell-cycle regulators is critical to optimizing targeted therapy in EC. This study investigated the molecular and functional effects of (Z)-endoxifen, alone and in combination with the CDK4/6 inhibitor abemaciclib, across diverse EC models to define mechanistic activity and translational potential. Methods: ER+ (Ishikawa, HCI-EC23, patient derived organoid U1561.005) and ER-variable (ARK1, ARK2) EC models were treated with estrogen (0-10 nM), (Z)-endoxifen (125 nM-10 µM) or fulvestrant (0-2.5 μM), and abemaciclib (0-10 μM), as single agents or in combination. Cell viability was assessed using luminescence-based assays. Dose-response analyses and combinatorial synergy were evaluated to determine endocrine sensitivity, ER dependency, and downstream cell-cycle effects. Results: Estrogen induced biphasic proliferative responses in ER+ models, confirming ligand-driven mitogenic signaling. (Z)-Endoxifen monotherapy suppressed viability across all cell lines, demonstrating superior potency to fulvestrant and activity independent of ER expression status. Mechanistically, (Z)-endoxifen abrogated estrogen-induced proliferative peaks, consistent with ER antagonism and potential receptor degradation, while also exerting ER-independent effects suggestive of cell-cycle modulation. Abemaciclib monotherapy inhibited viability in both ER+ and ER− models, and its combination with (Z)-endoxifen yielded strong synergistic activity (Chou-Talalay combination index &lt; 1), including in ER-negative ARK2 and the ER+ U1561.005 organoid. This synergy likely arises from concurrent disruption of ER signaling and CDK4/6-cyclin D regulatory pathways. Conclusions: (Z)-Endoxifen demonstrates dual ER-dependent and ER-independent activity in EC preclinical models. Synergy was observed in combination a CDK 4/6 inhibitor. These findings broaden the current understanding of (Z)-endoxifen’s efficacy and support further exploration of its potential therapeutic role in ER-driven and mixed-phenotype EC, including evaluation of responses across ER expression levels. Citation Format: Grace Choong, Xiaonan Hou, Sandra Suarez Hammer, Scott M. Blackburn, John Weroha, Steven C. Quay. (Z)-endoxifen modulates estrogen receptor and cell-cycle signaling to induce synergistic antiproliferative effects with CDK4/6 inhibition in endometrial cancer models [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 405.

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.

Abstract Glioblastoma (GBM) remains the most common and lethal adult malignant primary brain cancer with few treatment options. A significant issue hindering GBM therapeutic development is intratumor heterogeneity and plasticity. GBM tumors contain neoplastic cells within a fluid spectrum of diverse transcriptional states. Identifying effective therapeutics requires a platform that predicts the differential sensitivity and resistance of these states to various treatments. Here, we develop scFOCAL (Single-Cell Framework for -Omics Connectivity and Analysis via L1000), to quantify the cellular drug sensitivity and resistance landscape. Using single-cell RNA sequencing of newly diagnosed and recurrent GBM tumors, we identify compounds from the LINCS L1000 database with transcriptional response signatures selectively discordant with distinct GBM cell states, and leverage this capability to predict combination synergy. We validate the significance of these findings in vitro, ex vivo, and in vivo, and use the Olig2 inhibitor CT-179 as a reference drug to identify additional small molecules that would maximize the cell-drug discordance across the GBM transcriptional landscape. Our analysis leads to the combination of Olig2 inhibition with treatment with Depatux-M, of with which we demonstrate synergy in vivo. Our studies suggest that scFOCAL identifies cell states that are sensitive and resistant to targeted therapies in GBM using a measure of cell and drug connectivity, which can be applied to identify new synergistic combinations. Citation Format: Robert K. Suter, Anna M. Jermakowicz, Rithvik Veeramachaneni, Matthew D'Antuono, Longwei Zhang, Rishika Chowdary, Simon Kaeppeli, Madison Sharp, Pravallika Palwai, Vasileios Stathias, Grace Baker, Luz Ruiz, Winston Walters, Maria Cepero, Danielle Burgenske, Edward B. Reilly, Anatol Oleksijew, Mark G. Anderson, Sion Ll. Williams, Michael E. Ivan, Ricardo J. Komotar, Macarena I. De La Fuente, Gregory Stein, Alexandre Wojcinski, Santosh Kesari, Jann N. Sarkaria, Stephan C. Schürer, Nagi G. Ayad. Drug and single-cell gene expression integration identifies heterogeneity-aware synergistic combinations for glioblastoma [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 B032.

Abstract Chimeric antigen receptor T (CAR T)-cell therapy is revolutionizing cancer treatment in hematologic malignancies, but challenges related to the tumor microenvironment have hindered CAR T success, especially in solid tumors. Myeloid cells in particular have been implicated in CAR T efficacy. In this review, we discuss the roles of myeloid cells in CAR T–associated toxicities, including cytokine release syndrome, immune effector cell–associated neurotoxicity syndrome, and immune effector cell–associated hemophagocytic lymphohistiocytosis–like syndrome, along with strategies to treat these toxicities by modulating myeloid cells. The review also explores myeloid cell–mediated suppression or enhancement of CAR T function. Finally, strategies used to target myeloid cells in combination with CAR T-cell therapy will be investigated.

Introduction As part of the Society of Critical Care Medicine's Pediatric ICU Liberation Campaign Collaborative, Mayo Clinic developed a daily physician-led rounding checklist to promote timely de-escalation of ICU support and proactive measures to prevent iatrogenic conditions. We hypothesized that implementing this checklist would be feasible and would reduce missed opportunities to optimize care through both de-escalation and initiation of key preventive tasks. Methods We conducted a prospective study in a 16-bed medical/surgical PICU at a quaternary academic center over a 300-day period from May 2017 to March 2018. A 15-task daily rounding checklist was integrated into standard patient-centered rounds for every admitted patient to prompt physicians to address common de-escalation and preventive care tasks. For each task, physicians documented whether it had already been addressed during rounds, was not applicable to the patient, or the checklist directly prompted a plan modification. Trends in checklist compliance and the frequency/type of plan modifications were assessed in 60-day intervals to evaluate sustainability over time. Results 1,710 rounding checklists were completed across 2,424 patient-days (71% compliance). The checklist prompted 198 documented plan modifications from 9% of all completed checklists. The most frequent modifications involved initiating a bowel regimen ( n = 47), converting intravenous to enteral medications ( n = 32), initiating gastrointestinal prophylaxis ( n = 30), consulting rehabilitation services ( n = 18), and restarting home medications ( n = 18), which together accounted for 73% (145/198) of all modifications. Discussion Implementation of a daily rounding checklist was feasible, achieved acceptable compliance, and identified 198 opportunities for timely de-escalation and proactive care in a complex PICU environment. Although overall compliance did not meet the a priori &gt;75% target across the entire study period, early adoption exceeded this threshold and later decline highlighted sustainability challenges. This initiative demonstrates the potential of structured physician-led checklists to standardize care and reduce iatrogenic risk in pediatric critical care.