Cancer Genetics

Colorectal Cancer

 

Colorectal cancer is the third leading cause of cancer related deaths among Americans. More than 130,000 men and women in the United States are diagnosed with colon cancer each year. Endometrial (uterine) cancer is the fourth most common cancer in women, with 37,000 women being diagnosed annually.

 

These two cancers are indicators of an important hereditary cancer condition known as Hereditary Nonpolyposis Colorectal Cancer (HNPCC). HNPCC is the most common form of hereditary colon cancer and is responsible for 3/5% of all colorectal cancers.

 

HNPCC-Associated Cancers

HNPCC is associated with the following lifetime risks: an 80% risk of colon cancer, a 60% risk of endometrial cancer, a 12% risk of ovarian cancer and a 13% risk of gastric cancer.

 

In additions, HNPCC is associated with a greatly increased risk of other less common cancers including kidney/urinary tract cancer, biliary tract cancer and small bowel cancer.

 

HNPCC, You & Your Children

HNPCC-related cancers often develop at an early age, usually before the age of 50. The majority of HNPCC cancers are caused by inherited mutations in either of two specific genes—MLH1 and MSH2. Northside Hospital offers one of the most accurate tests available for identifying mutations in these genes.

 

If you have already been diagnosed with colorectal or endometrial cancer, genetic susceptibility testing to screen for HNPCC can be valuable to you for several reasons. It can help to determine if you are at increased risk of developing a second cancer of the colon or endometrium. Testing also is important because each child of a parent with an HNPCC gene mutation has a 50/50 chance for inheriting the altered genes. Knowing that you have HNPCC can help determine your risk and your family's risk for other cancers and assist your doctor in recommending appropriate cancer screening measures.

 

You Should Consider Genetic Testing to Screen for Colon Cancer if:

  • You have a personal or family history of colorectal cancer or endometrial cancer diagnosed before the age of 50.
  • You have a personal or family history of multiple HNPCC-related cancers in the same person (such as two colorectal cancers or both colorectal and endometrial cancer).
  • You have two first-degree relatives (parents, siblings, or children) who were diagnosed with colorectal or endometrial cancer at any age.
  • You have had more than 5-10 polyps removed.

 

Breast & Ovarian Cancer

Cancer Genetics Process