Immune Checkpoint Inhibition in Metastatic Colorectal Cancer Harboring Microsatellite Instability or Mismatch Repair Deficiency
Romain Cohen, Raphaël Colle, T. Pudlarz, Maximilien Heran, Alex Duval, Magali Svrcek, Thierry André
Abstract
Microsatellite instability (MSI) is a tumor phenotype related to a deficient DNA mismatch repair system (dMMR). This phenotype, observed in 5% of metastatic mCRC but 10-18% of localized CRC, is associated with high tumor mutational burden with highly immunogenic neoantigens. It has emerged as a major predictive biomarker for the efficacy of ICIs. In this review, we will present a comprehensive overview of the literature concerning the efficacy of ICIs in MSI/dMMR mCRC, with a focus on new developments in first-line metastatic setting. Then, we will present current and future challenges of immuno-oncology for patients with MSI/dMMR metastatic CRC.