Immune Checkpoint Blockade And Treatment For Mismatch Repair Deficient Cancers

At left, a possible mismatch repair cancer showing infiltrating  white blood cells. By Nephron - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=30309760

Interesting news on the cancer front: tumors exhibiting mismatch repair deficiency, in which DNA repair is aberrant and many mutations occur, produce many mutant proteins.  These can serve as “mutant neoantigens” - in theory recognized by the immune system. However, immune system checkpoint exists in cancer, preventing such recognition.  Therefore, immune therapy that targets and “blockades” such checkpoints, allowing for the recognition of these tumors and their mutant antigens, is a promising therapeutic approach.  The paper shows some positive results for colorectal cancers that are specifically exhibiting the mismatch repair problem.