335 Identification of individuals with a genetic predisposition for colon cancer—HNPCC

Abstract

Individuals from families with an inherited predisposition for colorectal cancer comprise a high risk population which would benefit from screening with colonoscopy and/or profylactic surgery. Hereditary non polyposis colon cancer is one of the most common genetic diseases in the Western world. As much as 1 in 200 can be a gene carrier and this syndrome is estimated to account for 5–10% of all colon cancers. These families are identified by frequent cases affected with colon cancer, often early onset and right sided. The predisposition shows an autosomal dominant mode of inheritance. The predisposed individuals also have an increased risk for cancers in other sites such as uterus, stomach, ovary and breast. Individuals at 50% risk are offered screening with colonoscopy. In families with other frequent tumors available screening for these are offered as well. Gene carriers identified by mutation analysis in any of the genes known to cause disease in these families have almost 100% risk of developing cancer and are offered screening procedures or prophylactic surgery.