Colonoscopic screening and subsequent removal of polyps at a 3-year interval in asymptomatic at-risk members of LS families has shown to reduce the incidence of colorectal cancer and improve overall survival. However, within such an interval in surveillance programs, interval cancers have been observed. It is therefore currently recommended that MMR gene mutation carriers should be kept under surveillance by regular colonoscopy every 1-2 years beginning at the age of 20-25 or 5-10 years younger than the earliest affected family member.