Up to 3-5% of all colorectal cancer is due to Lynch syndrome. People with Lynch syndrome have a 10-60% lifetime risk of developing colorectal cancer (compared to a 4% risk for people with average risk).

The average age of a colorectal cancer diagnosis for someone with Lynch syndrome can occur decades below the screening age of 45. Lynch syndrome is a common cause of colorectal cancer in young adults.

Colorectal cancer in Lynch syndrome patients may form quicker than in average-risk patients, and colorectal cancer screening, most often colonoscopy, will need to occur much more frequently for Lynch patients.