Abstract 6355: Building the first comprehensive research ecosystem and preclinical model platform for myoepithelial carcinoma

Abstract Myoepithelial carcinoma (MEC) is an ultra-rare, clinically aggressive malignancy (incidence 0.013/100,000) that affects both children and adults and arises in diverse anatomic sites, most commonly the salivary gland and soft tissues. Despite its severity, MEC remains profoundly understudied, with no established therapeutic standards and historically limited access to biospecimens, molecular data, or disease-relevant models. Although recurrent gene fusions, most frequently involving EWSR1 with partners such as ATF1, KLF15, KLF17, PBX1, and POU5F1, define a subset of pediatric and young adult cases, MEC overall exhibits substantial biological heterogeneity that has yet to be systematically characterized. To address longstanding barriers to progress, cureMEC: The Myoepithelial Carcinoma Project was launched in 2022 as a patient-driven research initiative dedicated to building the foundational infrastructure required to study MEC across molecular subtypes. In partnership with the Rare Cancer Research Foundation (RCRF) and Pattern.org, cureMEC has established the first dedicated MEC biorepository and integrated clinical-molecular data platform, supporting systematic specimen acquisition, multiomic profiling, and open-access research engagement. MEC biospecimens are now incorporated into large-scale programs spanning transcriptomics, proteomics, and high-throughput drug-screening pipelines. Early achievements include creation of the first coordinated MEC biobanking network and establishment of two novel MEC cell lines have been developed and identification of a patient-derived xenograft (PDX) molecularly confirmed to harbor EWSR1-KLF15. These models will support mechanistic studies of EWSR1-driven oncogenesis, surface-protein mapping to identify therapeutic targets, and high-throughput drug-repurposing screens across fusion-defined contexts. Together, these efforts establish the first integrated research ecosystem for MEC, combining patient partnership, biospecimen infrastructure, and proteogenomic discovery. This model demonstrates how patient-driven collaborations can rapidly build foundational scientific resources for ultra-rare cancers, creating the tools necessary to elucidate disease mechanisms and accelerate the development of targeted therapies. Citation Format: Jamie Barber, Naomi Natale, Michael Casaus. Building the first comprehensive research ecosystem and preclinical model platform for myoepithelial carcinoma [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 6355.