Patient derived xenografts (PDX) are valuable, clinically-relevant models of cancer. Their close genomic, phenotypic, and temporal association with patient tumors makes them well-suited for pre-clinical and co-clinical studies that assess the potential of new therapeutics. However, PDX models are not amenable to large-scale drug sensitivity studies or real-time precision oncology due to their relatively slow growth, high cost, and low throughput. To address this, we established and characterized organoid lines from breast cancer patient tumors and PDXs and evaluated their fidelity to the original tumors and their utility in high-throughput therapeutic studies. Results of comparisons between in vitro and in vivo patient-derived models of breast cancer will be presented, along with extension of this technology to inform patient care in an IRB-approved study of precision oncology. Our work demonstrates that breast cancer organoid models are a powerful parallel resource to PDX models, especially useful for efficient determination of drug responses, and are amenable to informing real-time patient care in a functional precision oncology setting.

Citation Format: Alana L. Welm. Using patient-derived models for functional precision oncology in advanced breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr SY16-02.