Immunotherapy and metastatic colorectal cancers with microsatellite instability or mismatch repair deficiency

Abstract

Microsatellite instability (MSI) is a molecular indicator of defective DNA mismatch repair (dMMR) and is observed in approximately 5% of metastatic colorectal cancers (mCRC). MSI is a major predictive biomarker for the efficacy of immune checkpoint inhibitors (ICKi) amongst mCRC patients. After summarizing the literature about the efficacy of conventional cytotoxic regimens, we will highlight studies that have demonstrated the clinical activity of ICKi for patients with chemoresistant MSI/dMMR mCRC. Then we will focus on ongoing clinical trials and emerging challenges for the treatment of patients with MSI/dMMR mCRC.

Keywords: BRAF; Colorectal cancer; Immune checkpoint; Lynch syndrome; Microsatellite instability; Mismatch repair.