Abstract 5561: Whole slide Imaging Mass Cytometry allows the rapid profiling of the immune landscape of histopathologically aggressive prostate tumors

Abstract Patients with Gleason pattern 4 or 5 prostate tumors have a high risk of biochemical recurrence and worse survival. Affected by their local environment, dynamic immune cell phenotypes can both hinder or drive cancer progression. To understand the proteomic environments that facilitate specific immune cell responses and interactions in advanced prostate cancer, we have spatially resolved the immune cell content and metabolic features of Gleason pattern 4 and 5 and subpatterns of prostate tumors. To scale quantitative multiplexed histopathology measurements to human disease, we have applied a new high-throughput whole slide modality of high-plex Imaging Mass CytometryTM to simultaneously quantify immune cells, metabolic states, prostate specific pathways, and biomarkers in 125 whole slide sections from 42 patients over 100 cm2 of tissue. It is essential to image whole slide sections in order to fully evaluate the complete heterogeneity of these cancer samples. In parallel, multi-region macrodissection shotgun proteomics and both glycan and extracellular matrix MALDI imaging mass spectrometry have quantified the proteome associated with specific immune cell environments. Together, we identify localized proteomic microenvironments associated with specific tumor supportive or inhibitory immune cell content in human tumors that may help differentiate which high-risk patients will have a rapid biochemical recurrence following radical prostatectomy. Citation Format: Jennifer L. Gorman, Lydia Y. Liu, Jordan P. Hartig, Nikesh Parsotam, Amanda Khoo, Vladimir Ignatchenko, Sarah Asbury, Somi Afiuni, Ricardo Gonzalez, Michael J. Geuenich, Caitlin F. Harrigan, Yuju Lee, Jianan Chen, Liang Lim, Qanber Raza, Peggi M. Angel, Kieran Campbell, Stanley K. Liu, Michelle R. Downes, Richard R. Drake, Thomas Kislinger, David King, Hartland W. Jackson. Whole slide Imaging Mass Cytometry allows the rapid profiling of the immune landscape of histopathologically aggressive prostate tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5561.