Mutations in NTHL1 often lead to increased polyps in the colon. Although research is still ongoing, there is thought to be a high risk associated with colorectal cancer and mutations in NTHL1. The National Comprehensive Cancer Network recommends that those with mutations in this gene get a colonoscopy every two to three years starting between the ages of 25-30. If polyps are found, colonoscopy frequency should be increased to every one to two years. If polyps become uncontrollable by colonoscopy, surgical measures should be considered.