Individuals with HNPCC have a significantly increased risk of developing colorectal cancer, often at a younger age than the general population. They are also at higher risk for other types of cancer, including endometrial cancer, ovarian cancer, gastric cancer, small intestine cancer, and certain types of skin cancer. Women with HNPCC may have a 40-60% lifetime risk of endometrial cancer and a 10-12% risk of ovarian cancer.
