HNPCC cancer risks (updated 2005) - now known as the Lynch Syndrome

People with an HNPCC gene mutation have greater than a 90 percent lifetime risk of developing some type of cancer.28 These individuals not only have an increased risk of colorectal and endometrial cancers, but also other cancers listed below: Cancer Type Mutation Carrier Risk1, 35 General Population Risk Colorectal Up to 82% 2% Endometrial Up to 71% 1.5% Stomach Up to 13% <1% Ovarian Up to 12% 1% * Patients with HNPCC may also have a slightly elevated risk of the following cancers when compared to the general population: ureter/renal pelvis, biliary tract, small bowel, pancreas, brain and sebaceous adenomas. Individuals with HNPCC who have already been diagnosed with cancer also have an increased risk of developing a second cancer. In these patients, there is a 30 percent risk of a second cancer developing within 10 years of initial diagnosis and a 50 percent chance of a second cancer developing within 15 years of initial diagnosis.