Immunotherapy has a established role in the treatment of metastatic colorectal cancer in patients with microsatellite instability/ deficiency in mismatch repair genes accounting for roughly 5% of all metastatic colorectal cancers. Data from smaller studies also strongly support similarly good efficacy in tumors with the POLE1/POLD1 mutation.
Intensive research is underway to break down the resistance to immunotherapy observed in microsatellite stable colorectal cancers. Some smaller non-randomized studies suggest a possible benefit of combining immunotherapy with multikinase inhibitors or chemotherapy and targeted treatment in the population of microsatellite stable tumors, but negative results from several recently published studies indicate the need for further research before implementation into clinical praxis.
Promising results were seen with novel generation of immunotherapy agents.