PD-008Molecular characterization of immune microenvironment in colorectal cancers with microsatellite instability by digital RNA counting

Introduction: Alterations in the mismatch repair (MMR) mechanism in colorectal cancers (CRCs) lead to high levels of microsatellite instability (MSI-h) causing considerable endogenous immune anti-tumor response, counterbalanced by immune inhibitory signals. We evaluated the mRNA immune-profile of a series of MSI-h CRCs to identify new potential targets for future CRC immunotherapy trials by combining an extensive gene expression analysis and the clinicopathological characteristics such as presence of metastases, staging, genotype and primary tumor sidedness.