Colon Cancer and Genetic Testing: Questions Answered

Colon cancer is the 2nd leading cause of cancer deaths in the U.S. - which puts the lifetime risk of developing the disease at 4%. Karen Huelsman, a licensed and certified genetic counselor with TriHealth Cancer Institute, says your family history can provide important information about your risk.

If you have a first degree relative with colon cancer, your risk increases 2-3 fold. If you have a significant family history of colon cancer, with multiple affected individuals or early age at diagnosis, there could be a hereditary cause and your risk could be much higher.

While there may not be a cure for cancer, the American Cancer Society indicates that the 5-year survival rate for people with stage one colon cancer is approximately 90% as opposed to the survival rate for stage four colon cancers, which is approximately 11%. This indicates that colon cancer is very treatable if is detected early.

Research published in 2010 found that hereditary colorectal cancers account for about 3-5% of all colorectal cancers. What's more, individuals with a hereditary cancer syndrome are at increased risk for developing an initial cancer as well as a second primary cancer in their lifetime. Some hereditary cancer syndromes, those genes with the highest risk, have lifetime risks to develop colon cancer as high as 80-99% by age 80.

Knowing family history can help your doctor determine a risk-based medical management plan for screening and risk reduction. Huelsman says this is the reason it is so important to identify families with a high level risk. "We look at red flags for inherited cancer such as early age of onset before 50, multiple cancers related by the same gene, and multiple family memebrs who are affected by cancer."