Genetic Testing for Colorectal Cancer
If your doctor finds multiple polyps during a colonoscopy, it may indicate that you have hereditary colon cancer. About 5 to 10 percent of colorectal cancer cases are due to specific genetic mutations passed from parents to children. Our Clinical Genetics Service offers counseling and education about the risk of hereditary forms of colorectal cancer, as well as genetic testing for you and your family members.
During genetic testing, we look at a sample of your blood for changes in your genes that are associated with hereditary colorectal cancers. Knowing which mutation may be present helps your treatment team determine which condition you have. This, in turn, helps refine your overall plan of care. Even if we don’t find a mutation, our counselors may recommend that you have more frequent cancer screening and surveillance, or that you consult with a particular kind of colorectal specialist.
Learn more about the hereditary disorders leading to colorectal cancer.
Familial Adenomatous Polyposis
Familial adenomatous polyposis (FAP) — caused by an inherited gene mutation — can lead to multiple polyps in the colon and rectum. Attenuated FAP is a milder form.
People with Lynch syndrome, also called hereditary nonpolyposis colorectal cancer, have an 80 percent risk for colorectal cancer. They’re also more likely to get certain other cancers.
MYH-associated polyposis, caused by a different gene mutation than FAP, leads to multiple adenomatous colon polyps.
Hyperplastic Polyposis Syndrome
Hyperplastic polyposis syndrome (HPS) is characterized by the development of multiple enlarged hyperplastic colon or rectal polyps. There are no genetic tests for HPS.