Pembrolizumab in MSI-H–dMMR Advanced Colorectal Cancer — A New Standard of Care

Nothing has changed cancer therapy more in the past 5 to 10 years than the introduction of immune checkpoint inhibitors. In solid tumors, the activity of these agents is commonly linked to the presence of a hypermutated phenotype with the expression of tumor-specific neoantigens at the surface of cancer cells that can serve as targets for T cells. A higher tumor mutation burden can be the result of exogenous, DNA-damaging carcinogens, such as ultraviolet light and smoking, or linked to cell-intrinsic deficiencies in DNA repair mechanisms. Germline mutations in genes encoding mismatch repair proteins are the hallmarks of the Lynch . . .