Abstract 5693: Tumor whole-transcriptome sequencing and multiplex immunohistochemistry of immune cell populations in 158 Asian colorectal cancers

Background: Colorectal cancer (CRC) is a cancer largely refractory to immune checkpoint inhibition. There is substantial interpatient molecular heterogeneity in colorectal cancer reported from studies on tumor RNA and studies on immunohistochemical analyses of fixed tumor tissue. Several major transcriptomic analyses from microarrays and RNA-seq data have identified major transcriptomic subtypes and major activated pathways and deconvoluted cell-type enrichments. Immunohistochemical (IHC) analyses of formalin-fixed, paraffin-embedded (FFPE) tissue microarrays have identified several different histomorphologic/spatial patterns of immune infiltrates in the tumor microenvironment. Here, we perform large-scale -omic analyses on tumor RNA and multiplex IHC simultaneously on 158 Asian colorectal cancers. Methods: We performed whole-genome sequencing (WGS) (60x tumor, 30x normal) and deep whole-transcriptomic sequencing (RNA-seq) (∼200x10 6 reads per tumor) on 158 colorectal cancers. To evaluate the spatial patterns of the tumor microenvironment, we constructed a tissue microarray comprising the tumor core, tumor edge and normal adjacent tissue of these 158 CRCs. We performed HE 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5693.