Vanderbilt-Ingram Cancer Center

Why is it important to be screened for colon cancer?

The goal of colorectal cancer screening is to keep you from dying from colorectal cancer. These tests help identify cancers early during a treatable stage.

Some tests can prevent colorectal cancer development by finding precancerous growths called adenomatous polyps. These polyps can be removed before they turn into cancer. Many times colon cancer does not cause symptoms until it has advanced making it harder to treat. You should not wait until you have problems before looking for cancer.

What is your doctor looking for when you have a colonoscopy?

A colonoscopy is a test that looks at your colon's inside lining. This test allows your doctor to find cancer and precancerous growths. A simple procedure to remove the polyp is done during the colonoscopy if one is found. Knowing if you have these precancerous growths (or not) helps:

• Your doctor determine your future risk of cancer
• Your medical team know how often to check back for any abnormalities in the future  

Why is it recommended to wait ten years between colonoscopies? Is it because colon cancer is always slow growing?

For those with an average colorectal cancer risk, the current recommendation to have a colonoscopy is every 10 years starting when you are 50. This age is based on the fact that 90 percent of colorectal cancers happen in those older than 50. Recommendations on how often to repeat this exam are based on what is found during the initial colonoscopy in terms of:

• Number of polyps
• Size
• How they look under the microscope

Research shows that it takes polyps, on average, 10 years to progress to cancer, but colon cancers are not always slow growing. Your doctor has to measure your risk based on what he or she finds during your colonoscopy as well as your medical and family history.

How do you know you're at high risk for colon cancer, and what are the recommendations for those that do not know their family's medical history?

You may be at high risk for colorectal cancer if you have had:

• Colorectal cancer
• A precancerous polyp
• A history of ulcerative colitis
• A history of Crohn’s disease

If there is a family history, we would want to know how many family members have had colorectal cancer and at what age were these abnormalities found. In some cases, those that have a family history with other cancers may also be more at risk for colorectal cancer. If you do not know your family history, we recommend following the guidelines for someone of average risk.

What should you do when you are at high risk for colon cancer?

Your screening recommendations may vary based on the reason you are at risk for developing colorectal cancer.

• If you have a parent or sibling who has had colon cancer, you should have your first colonoscopy at age 40 or 10 years prior to when that person was diagnosed, whichever is earlier. 
• Individuals that have an inherited colorectal cancer syndrome, such as Lynch Syndrome, are recommended to begin getting colonoscopies at age 20-25 years. This is done every 1-2 years.
• In families that have polyposis syndromes (where the colon has hundreds to thousands of polyps), screening begins in adolescence. Typically, the whole colon is removed in early adulthood before cancer develops.

It is important to discuss your family history of colorectal cancer with your primary care provider. Your risk can be assessed and a screening plan can be tailored to you. If you would like more information regarding inherited colon cancer syndromes, contact Duveen Sturgeon at the Vanderbilt Hereditary Colorectal Cancer Registry (615) 322-1590.