359P Analysis of TMB and tumor microenvironment in Polymerase epsilon (POLE) deficient colorectal cancer

Abstract

POLE (DNA Polymerase Epsilon, Catalytic Subunit) is a protein coding gene. This gene encodes the catalytic subunit of DNA polymerase epsilon, involved in DNA repair and chromosomal DNA replication. Mutations in this gene, especially related to proofreading defects in the POLE polymerase (POLE pd), have been associated with hypermutated genomes and sensitive response by checkpoint blocking immunotherapies for colorectal cancer (CRC). The profile of Tumor mutation burden (TMB) and tumor microenvironment between POLE mutation(POLEmut) and POLE wildtype(POLEwt) CRC is not clearly elaborated.