Abstract LB_C17: Spatial tumor immune microenvironment analysis of KRAS-mutated Non-Small Cell Lung Cancer and immunotherapy outcome

Abstract

Abstract Targeting KRAS in lung cancer is promising and the immune modulatory effects of KRAS inhibition is interesting. Understanding the local tumor immune architectures are important to overcome the treatment resistance of immunotherapy and targeted therapy. We conducted spatial immune tumor microenvironment (iTME) profiling using FFPE samples of 25 KRAS mutated non-small cell lung cancer patients treated with immune checkpoint inhibitors (ICIs), which included 12 responders and 13 non-responders. We used an eleven-markers panel (CD3, CD4, CD8, Foxp3, CD68, Arginase-1, CD33, HLA-DR, Pan-Keratin (PanCK), PD-1 and PD-L1). We studied the tumor and immune cell compositions and spatial features at single cell level with cellular neighborhood and fractal analysis. We found spatial features and the different subgroups of CD68 positive cells and Foxp3+ cells associated with responses and resistance to ICIs. We found that CD68+ cells, CD33+ cells and Foxp3+ cells are associated with resistance to ICIs of KRAS mutated lung cancer. Interestingly, we found that cells had non-nuclear expression of Foxp3 were associated with ICIs resistance. We identified a population of CD68 weakly positive cells in the tumor tissues were associated with responses to ICIs. We identified two different groups of non-responders: one with high diversity of cells and one with low diversity, while all the responders had high diversity. We identified nine cellular neighborhoods (C0-C8) with C0 in majority of non-responders, which was enriched with PanCK+, CD33+, and Foxp3+ T regulartory cells. Conversely, most responders were enriched with C3 and C6-C7, which contained CD8+ T cells and CD68 weakly positive cells. Our study had revealed the spatial immune features of KRAS mutated lung cancer and their association with immunotherapy outcome which could be helpful for KRAS targeting and immunotherapy. Citation Format: Dan Zhao, Haiqing Li, Isa Mambetsariev, Tamara Mirzapoiazova, Chen Chen, Jeremy Fricke, Deric Wheeler, Leonidas Arvanitis, Raju Pillai, Michelle Afkhami, Bihong T. Chen, Martin Sattler, Loretta Erhunmwunsee, Erminia Massarelli, Prakash Kulkarni, Arya Amini, Brian Armstrong, Ravi Salgi. Spatial tumor immune microenvironment analysis of KRAS-mutated Non-Small Cell Lung Cancer and immunotherapy outcome [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_C17.