New Therapeutic Opportunities Based on DNA Mismatch Repair and BRAF Status in Metastatic Colorectal Cancer

International audience; Recently, colorectal cancer (CRC) subtyping consortium identified four consensus molecular subtypes (CMS1–4). CMS1 is enriched for deficient mismatch repair (dMMR) and BRAF V600E tumors. Intriguingly, this subtype has better relapse-free survival but worse overall survival after relapse compared with the other subtypes. Growing evidence is accumulating on the benefit of specific therapeutic strategies such as immune checkpoint inhibition therapy in dMMR tumors and mitogen-activated protein kinase (MAPK) pathway targeted therapy in tumors harboring BRAF V600E mutation. After reviewing dMMR prognostic value, immune checkpoints as major targets for dMMR carcinomas will be highlighted. Following, BRAF V600E prognostic impact will be reviewed and therapeutic strategies with the combination of cytotoxic agents and especially the combinations of BRAF and MAPK inhibitors will be discussed.