Citations

e16486 Background: Allele-specific KRAS G12C inhibitors have revolutionized lung and colorectal cancer treatment, yet the biology of G12C in other gastrointestinal (GI) malignancies remains undefined. We aimed to elucidate the clinicopathologic and genomic landscape of KRAS G12C-mutated tumors compared to other G12 variants in a large non-colorectal GI cohort. Methods: We queried cBioPortal for pancreatic, esophagogastric, hepatobiliary, ampullary, and appendiceal adenocarcinomas. Following data quality control, the final cohort (n = 6,352) was stratified into KRAS wild-type (n = 3,293), G12C (n = 63), and other G12 variants (n = 2,996). Clinicopathologic features, tumor mutational burden (TMB), microsatellite instability status, and co-alteration in 96 key genes across 11 signaling pathways were compared. Statistical significance was assessed using Fisher’s exact or Chi-square tests for categorical variables and Kruskal-Wallis tests for continuous variables. The Benjamini-Hochberg method was applied to correct for multiple hypothesis testing. Results: KRAS G12C prevalence was 1.0% overall, with significant heterogeneity across cancer subtypes (p < 0.001). Appendiceal adenocarcinoma demonstrated the highest G12C prevalence at 5.71% (10/175), followed by ampullary (1.44%, 2/139), pancreatic (1.17%, 34/2906), hepatobiliary (0.88%, 12/1360), and esophagogastric cancers (0.28%, 5/1772). G12C patients were significantly older than wild-type patients (64.8±11.2 vs 62.5±12.9 years, mean±SD, p < 0.001) but younger than other G12 variant carriers (65.8±10.4 years). G12C tumors demonstrated intermediate genomic instability, with a TMB of 4.82±6.17 compared to 4.98±10.55 in wild-type tumors and 3.67±10.12 in other G12 variants (p < 0.001). Notably, G12C tumors were universally microsatellite stable (0% MSI-H vs 4.0% wild-type vs 0.9% other G12, p < 0.001). Genomic analysis revealed that AKT1 mutations were significantly enriched in the G12C cohort (6.3% vs 0.4%; q = 0.025) as compared to other G12 variants. A trend of increased mutation frequency in HRAS was observed specifically in pancreatic cancers in G12C tumors as compared to other variants (8.8% vs 0.7%; q = 0.083). In pancreatic adenocarcinoma, G12C tumors were enriched for chromatin modifiers, notably ARID1A (17.6% vs 7.7%, p = 0.045) and SETD2 / SETD26 (8.8% vs 1.1%, p = 0.006), though these did not reach FDR significance. Notably, the immunotherapy-resistance drivers STK11 and KEAP1 were absent (0%) in the whole G12C cohort. Conclusions: KRAS G12C represents a biologically distinct subgroup of exon 2 KRAS mutations compared to other KRAS G12 pathogenic variants. The absence of resistance markers and enrichment of actionable AKT1 and chromatin-modifier mutations suggest distinct therapeutic vulnerabilities in non-colorectal KRAS G12C-mutated GI cancers.

Abstract The proliferation of advanced endoscopic resection techniques has provided a minimally invasive alternative to esophagectomy and revolutionized outcomes for patients with early-stage esophageal adenocarcinoma (EAC). This paradigm shift and the resulting research data on clinical and histologic determinants of treatment outcome have highlighted the heterogeneity of outcomes within EAC staged as T1 by invasion depth. Multidisciplinary cancer care teams are now routinely facing difficult decisions regarding the management of high-risk T1 EAC to balance the risk of long-term lymph node (LNM) or distant metastasis against the risks of surgical resection. In this review, we summarize the current state of knowledge regarding the staging and risk stratification of T1 EAC, with particular attention to features that contribute to a higher risk of LNM and cancer mortality. We review recent clinical trial data on positioning the use of endoscopic resection (cap-assisted or submucosal dissection) versus surgical resection in high-risk T1 EAC patients and describe adjunctive techniques to further improve risk stratification and treatment. Finally, we explore emerging and future directions, such as artificial intelligence and advanced biomarker analysis to further aid decision-making and enhance patient outcomes.

Background: The purpose of this study was to describe, and report the outcomes of, a surgical technique that combines reverse shoulder arthroplasty (RSA) using an allograft-prosthetic composite (APC) with a lower trapezius transfer (LTT) to the infraspinatus of the allograft extended with the inferior capsule. Methods: Between 2019 and 2023, 2 surgeons performed a total of 27 RSAs using an APC in conjunction with an LTT. Once the RSA APC reconstruction had been performed, cuff-capsule allograft tissue was passed posterior to the glenosphere and secured to the harvested lower trapezius. One shoulder was resected for periprosthetic joint infection; the remaining 26 shoulders were followed for a minimum of 2 years (mean, 2.7 years; range, 2 to 5 years). Results: The rate of revision or reoperation for humeral complications was 15% and included secondary bone grafting (2 shoulders), resection for infection (1 shoulder), and internal fixation of a periprosthetic fracture (1 shoulder). Other complications requiring surgery included hematoma treated with evacuation (2 shoulders), dislocation (1 shoulder), and glenosphere disassociation (1 shoulder). Preoperatively, 11 shoulders presented with pseudoparalysis, and the mean active elevation of the remaining 16 shoulders was 43°, with only 1 shoulder demonstrating >90° of active elevation. At the most recent follow-up, 3 shoulders were pseudoparalytic, 11 had <90° of active elevation, 8 had >90° of active elevation, and 3 had active elevation to 90°. The overall mean active elevation of the 25 shoulders that could be assessed was 79°. Preoperatively, only 4 (15%) of the 27 shoulders demonstrated active external rotation past neutral; at the most recent follow-up, 80% of surviving shoulders had active external rotation past neutral. Conclusions: LTT at the time of RSA using an APC has the potential to restore active external rotation in shoulders with proximal humeral bone loss and posterosuperior cuff deficiency. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

ABSTRACT Richter transformation of Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) into classic Hodgkin lymphoma (CHL-RT) is rare and remains incompletely understood. Two histologic subtypes are recognized: type 1 (CLL/SLL with scattered Hodgkin/Reed-Sternberg (HRS) cells) and type 2 (HRS cells within a polymorphous inflammatory background). In this multi-institutional study of 77 patients with CHL-RT (27 type 1 and 50 type 2), we characterized immune evasion markers, PD-L1 / PD-L2 copy number alterations, tumor microenvironment, and performed targeted next-generation sequencing on 37 CLL/SLL samples. HRS cells in CHL-RT displayed immune-evasion phenotypes similar to de novo CHL, though PD-L1 expression was lower in type 1 cases. PD-L1/PD-L2 gain/polysomy were frequent (83.3%). CLL/SLL with CHL-RT harbored increased mutations in XPO1, FBXW7, BIRC3, TRAF3 , and HLA-A versus reference CLL/SLL. Similar mutational profiles, demographics, and survival outcomes support a biological continuum between type 1 and type 2 CHL-RT, with distinct genetic features in CLL/SLL predisposing to CHL transformation. STATEMENT OF SIGNIFICANCE Classic Hodgkin lymphoma-type Richter transformation arises from convergent Hodgkin-like immune evasion on a genetically primed CLL/SLL background. Through integrated genomic and tumor microenvironment analyses in a large multicenter cohort, we establish this as a biologically coherent entity and provide rationale for PD-L1/PD-L2-directed therapeutic strategies.

Abstract Members of the Transient Receptor Potential (TRP) family of ion channels have a nearly ubiquitous role in human physiology, tuning cell signaling to remarkably diverse physical and chemical stimuli. Although there is extensive structural data on TRP channels, a systematic and unbiased interrogation of structure-function relations in these proteins is required to fully elucidate their mechanisms of function. By focusing on a critical pore region of the TRPM8 channel, which is the main detector of cold and cooling agents in sensory neurons, we show how deep mutational scanning can be used in combination with the available structural data to understand how TRP channels respond to stimuli. We define a novel mechanism whereby the extracellular pore loop, which has only been resolved in structures representing desensitized states of the channel, plays an essential role in the response of TRPM8 to menthol or cold by coordinating the movement of the S6 helices that line and gate the pore, and the ion-selectivity filter that binds permeant cations. Moreover, our screen reveals sequence determinants along the S6 helices that explain how their architecture sustains gating and, together, provide strong support for a structural mechanism of TRPM8 pore opening in response to menthol and cold.

Background: The timing of coronary artery bypass grafting (CABG) in patients with non-ST-elevation myocardial infarction (NSTEMI) may critically impact clinical outcomes, yet the ideal surgical window remains unclear. We aimed to evaluate the association between time-to-CABG and in-hospital outcomes among NSTEMI admissions undergoing CABG. Methods: This retrospective cohort study utilized the US National Inpatient Sample database from 2017 to 2021 to evaluate the association between time-to-CABG and key in-hospital outcomes, including mortality, cardiac arrest, cardiogenic shock, ischemic stroke, acute kidney injury, and blood transfusion rates, while assessing length of stay (LOS) and hospital charges exclusively among survivors. Adult admissions with principal diagnosis of NSTEMI who underwent CABG without prior interhospital transfer were grouped by the calendar day of CABG from admission (0, 1, 2, 3, 4, 5, 6, and ≥7). Multivariate regression models were used to assess the outcomes across these eight groups. Results: Of 142,200 included admissions, same-day CABG (hospital day 0) was associated with the highest rates of in-hospital mortality, cardiac arrest, cardiogenic shock, and ischemic stroke. The adjusted odds of mortality, cardiac arrest, and cardiogenic shock were lower among admissions undergoing CABG between days 2 and 5. Likewise, the adjusted odds of ischemic stroke were lowest when CABG occurred on days 2 to 4. The odds of AKI increased when CABG was delayed beyond day 6, whereas blood transfusion rates showed no statistically significant association with time-to-CABG. Among survivors, LOS and hospital charges progressively increased with delayed CABGs. Conclusions: Among NSTEMI admissions undergoing CABG, CABG performed on hospital days 2 to 4 was associated with lower adjusted odds of several adverse in-hospital outcomes compared with same-day CABG. Further prospective studies are needed to validate these results and guide clinical decision-making.

ABSTRACT In 2018, the International Niemann‐Pick Disease Alliance (INPDA) and the International Niemann‐Pick Disease Registry (INPDR) developed and published comprehensive clinical management guidelines to support inclusive and standardized care pathways in Niemann‐Pick disease type C (NPC)—an ultra‐rare, autosomal recessive, neurovisceral lysosomal disorder. Since then, advances in diagnostics, care, and the approval of two novel disease‐modifying agents have underscored the need to revise these guidelines to ensure safe, consistent, and high‐quality care for those affected by NPC. In response, the INPDA and INPDR convened a multidisciplinary Guidelines Development Group (GDG) comprising individuals with NPC expertise from 14 countries across five continents, representing a broad range of specialties, as well as patients and families involved in NPC care. Informed by a comprehensive literature review and two meetings, the GDG systematically reviewed, revised, and updated the 2018 guideline statements, re‐evaluating the level of evidence, strength of recommendations, and expert agreement for each. The resulting 2025 consensus clinical management guidelines constitute a timely, up‐to‐date, and internationally applicable resource for the diagnosis, treatment, and holistic management of individuals with NPC. These guidelines serve as a critical resource for specialist centers, hospital‐based medical teams, staff involved in NPC patient care, family physicians and other primary caregivers, and, importantly, patients and their families.

Background The PREPARE trial (Pragmatic Randomized trial Evaluating Pre-operative Alcohol skin solutions in Fractured Extremities), published in February 2024, demonstrated that 0.7% iodine povacrylex in 74% isopropyl alcohol reduced surgical site infections in patients with closed fractures compared with chlorhexidine gluconate in 70% isopropyl alcohol. Prior studies have shown that the translation of clinical trial findings into routine clinical practice and surgical procedures frequently takes longer than a decade, and strategies to accelerate implementation in orthopaedic surgery remain poorly defined. Engaging in a multifaceted implementation strategy with minimal barriers to entry for providers may be able to reduce this time to widespread adoption. Questions/purposes (1) Can the low-cost single-center dissemination efforts of the PREPARE trial results change antiseptic usage? (2) If a true practice change occurs, can the change be sustained over time without additional dissemination efforts? (3) Does the adoption of new evidence vary between fellowship-trained orthopaedic trauma surgeons and orthopaedic trauma surgeons who are not fellowship-trained? (4) What is the economic impact of a practice change to iodine povacrylex on hospital purchasing costs? Methods This was a retrospective, historically controlled comparative study of patients who underwent operative treatment of an extremity fracture at a single, urban, Level I academic trauma center before and after a dissemination effort aimed at increasing PREPARE trial awareness. A multifaceted dissemination strategy consisting of surgeon and nursing education, posted reminders, and supply chain support was implemented at the study site in February 2024. Patients were analyzed across three time periods: before dissemination (January 2020 to January 2024), during the transition (February 2024), and after dissemination (March 2024 to July 2025). An electronic medical record query identified patients with operative fracture management procedural codes who had a recorded antiseptic skin prep in the surgical flow sheet between January 2020 and July 2025. A total of 4822 patients were identified, and 222 duplicate entries were excluded, leaving 4600 patients for analysis (3351 before dissemination, 49 transitional, and 1200 after dissemination). To validate the completeness of our electronic health record query, we performed manual random sampling of monthly operative case logs, confirming that this query strategy successfully identified all patients with the relevant Current Procedural Terminology codes (that is, there were no exclusions for lack of antiseptic documentation). There were no differences in patient demographics, including sex, ethnicity, open fractures, or the distribution of upper and lower extremity fractures. Choice of surgical skin antiseptic was compared before and after dissemination using a log-binomial model. Results Dissemination efforts changed antiseptic use patterns with an immediate increase in iodine povacrylex use from 0.8% (27 of 3351) before intervention to 86% (1033 of 1200) after intervention (OR 765 [95% confidence interval 488 to 1197]; p < 0.001). This high level of use remained stable throughout the 17-month postintervention period without any additional dissemination efforts (p = 0.20 for trend). Adoption was higher among fellowship-trained trauma surgeons (94.8% increase) compared with surgeons without trauma fellowship training (34.7% increase). Hospital antiseptic product purchasing data, which reflect usage and restocking and were used as a secondary metric of practice change, also demonstrated an increase in iodine povacrylex demand and decline in chlorhexidine demand. Conclusion A targeted and multifaceted dissemination strategy led to rapid adoption of iodine povacrylex for use as the preferred surgical skin antisepsis in fracture surgery at our institution, which was sustained over the 17-month postintervention period. This finding contrasts with a historically slow uptake of surgical trial evidence into clinical practice. Pragmatic, low-cost approaches such as surgeon leadership, team-based multidisciplinary education, workflow reminders, and supply chain readiness may help to accelerate translation of evidence into orthopaedic practice. Future studies should evaluate the long-term sustainability of practice changes, surgical site infection outcomes, and generalizability across institutions. Level of Evidence Level III, therapeutic study.

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.