Cancer prevention by aspirin in children with Constitutional Mismatch Repair Deficiency (CMMRD).

Constitutional MisMatch Repair Deficiency (CMMRD) is caused by homozygous or compound heterozygous germline variants in one of the mismatch repair (MMR) genes (MSH2, MSH6, PMS2, MLH1). This syndrome results in early onset colorectal cancer, leukemia and lymphoma, brain tumors and other malignancies. Children with CMMRD are at high risk of developing multiple cancers and cancer surveillance does not guarantee detection of cancer at a curable stage. The development of a preventive treatment strategy would be a major step forward. Long-term daily use of acetylsalicylic acid (ASA) has been shown to reduce cancer risk in individuals with Lynch syndrome (LS). LS is caused by heterozygous germline variants of MSH2, MSH6, PMS2 and MLH1 and characterized by an increased risk of developing colorectal and endometrial cancer at adult age. Here we discuss the potential use of ASA for cancer prevention in patients with CMMRD.