Abstract B022: A Living Biobank and Functional Precision Oncology Platform for Rare Cancers

Abstract

Rare cancers collectively account for ∼25% of all cancer diagnoses, yet they remain disproportionately understudied due to limited patient numbers, biological heterogeneity, and a lack of robust preclinical models. This gap has constrained mechanistic understanding and slowed the development of effective therapies, leaving many patients with limited treatment options. To address these challenges, we established a living biobank of 247 rare tumor specimens with banked materials (e.g., RNA, DNA, FFPE tissue) and associated molecular data, including RNAseq profiles. The collection also includes 112 cryopreserved microtumor or tissue fragments and 11 patient-derived xenograft (PDX) models, complemented by integrated multi-omic datasets from over 1000 additional rare tumors curated from public repositories. Building on this foundation, we developed patient-derived microtumor cultures as a central functional platform. These three-dimensional tissues preserve native tumor architecture and key components of the tumor microenvironment (TME), including stromal and immune elements, enabling more physiologically relevant modeling than conventional systems. This approach bridges ex vivo and in vivo models, supporting rapid drug sensitivity testing, efficient generation of PDX models, and capturing therapeutic responses often missed in standard cell culture. Using this integrated platform, we have identified novel and potentially actionable therapeutic vulnerabilities across multiple rare cancers, including sensitivity to CDK4/6 inhibition in rare bladder cancer, PLK1 inhibition in fibrolamellar carcinoma, and synergistic targeting of MEK and YAP signaling in solitary fibrous tumors. Together, this combined biobanking and functional precision oncology framework provides a scalable and translationally relevant approach to accelerate therapeutic discovery and expand treatment opportunities for patients with rare cancers. Songli Zhu, Joel Vaz, Deanna Mische, Marina Chan, Taran Gujral. A Living Biobank and Functional Precision Oncology Platform for Rare Cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Breaking Barriers in the Fight against Rare Cancers; 2026 Jul 18-20; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86(14_Suppl):Abstract nr B022.