Abstract P056: Rapid serial immunoprofiling of the tumor immune microenvironment by fine needle sampling

Abstract

Abstract As the field of cancer immunotherapy brings forth novel and combinatorial agents, there is increasing effort to discover and integrate predictive and/or prognostic biomarkers into treatment algorithms in order to optimize cancer care. While tissue-based methods can elucidate tumor-immune cell compositions at a single time point, serial assessment of the tumor immune microenvironment (TME) can provide unique insight into how various therapies may modulate target tumor and/or immune cell populations over time. We propose that single-cell sampling via fine needle aspirates (FNA) can facilitate such analyses with a favorable risk-benefit profile. Thus, we developed and optimized a multiplexed bioorthogonal approach (FAST-FNA) which has been coupled with a deep learning algorithm that allows for comprehensive cellular analyses of FNA samples. We demonstrate that the FAST-FNA assay reproducibly captures the TME profile as compared to standard labor-intensive flow cytometry and immunohistochemical assays, and, furthermore, allows for time course analysis of the evolving TME in mouse and human cancers in vivo. The translational significance of the FNA-based technology is highlighted in the ability to rapidly assess PD-L1 expression within the TME and is further extended through the serial quantitation of both tumor and immune cell markers in cancer patients treated with immunotherapy. Collectively, these data indicate that FAST-FNA can serve as a robust and versatile clinical tool to monitor the evolving TME and has the potential to provide early insight into treatment response. Citation Format: Juhyun Oh, Jonathan C. T. Carlson, Christian Landeros, Hakho Lee, Scott Ferguson, William C. Faquin, John R. Clark, Mikael J. Pittet, Sara I. Pai, Ralph Weissleder. Rapid serial immunoprofiling of the tumor immune microenvironment by fine needle sampling [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P056.