Colon cancer has become a hot topic in the media as new discoveries are uncovered about the causes and more young people are being diagnosed. It’s more important than ever to ensure you are getting your colorectal cancer screenings at the right time. We asked board-certified general and colorectal surgeon, Dr. Coen Klos, for the breakdown on the different screening options available for colon cancer.
Who is considered average versus higher risk for colorectal cancer?
One of the main risk factors for colon cancer is family history, if you have a first-degree family member with a history of colon cancer (parent, sibling, or child), or multiple family members of the second degree (grandparent, aunts/uncles) you are considered high risk. Additionally, a personal history of precancerous colon polyps or colon cancer also puts you at a higher risk of future polyps or cancer.
Less common conditions that increase the risk of colon cancer include Inflammatory Bowel Disease (Crohn’s or Ulcerative Colitis), or hereditary cancer syndromes such as Lynch Syndrome and Familial Adenomatous Polyposis. If you do not have a family history of colon cancer, you are likely to be at average risk.
Individuals who are at high risk are typically recommended to complete a colonoscopy versus a stool test.
What are the recommended screening guidelines for colorectal cancer?
Current recommendations are to start screening at age 45 up to the age of 75 for an individual at average risk.
After the age of 75, the decision to undergo further screening should be made on an individual basis, considering your overall health and life expectancy, and may be decided based on discussion with your physician.
Those with any family history of colon cancer should ask their physician if they are at increased risk of colon cancer. Those with a first-degree family history should typically start screening 10 years before the age their family member was diagnosed, or at age 45 (whichever comes first).
What are the screening methods?
Stool-based tests
These tests check the stool (feces) for signs of colon or rectal cancer, such as small amounts of blood. These tests are non-invasive and are easier to do than visual exams, but they need to be done more often.
Recommended yearly:
- Fecal Immunochemical Test (FIT): checks for hidden blood in the stool from the lower intestines.
- Cologuard: look for certain abnormal sections of DNA or RNA from cancer or polyp cells, as well as for occult (hidden) blood.
Visual exams of the colon and rectum
- Colonoscopy: a physician examines the entire length of the colon and rectum with a colonoscope, a flexible tube with a light and small video camera on the end. It’s put in through the anus and into the rectum and colon. (every 10 years for average risk)
- Sigmoidoscopy: a procedure used to see inside the sigmoid colon (the last one-third of the colon) and rectum (which connects the sigmoid colon to the anus). (every five years, 10 if combined with yearly stool blood test)
- CT colonography: an advanced type of computed tomography (CT) scan of the colon and rectum that can show abnormal areas, like polyps or cancer. (every five years)
What are the benefits and limitations of the different screenings?
Stool-based tests
For the patient there are minimal logistics and risks involved: no bowel prep, sedation, invasive procedure, or need for someone to accompany you to and from the test. Collection can even be completed in the privacy of your home and then sent off to the lab.
However, the results provide limited information and a colonoscopy may still be required if the test result is positive. Additionally, the tests need to be repeated more frequently and are not adequate for high-risk individuals.
Some insurance plans may only cover one screening exam per a certain number of years (check your policy). If a stool test is chosen as the screening exam and then it’s determined a colonoscopy is needed, the colonoscopy may not be covered as a screening exam but rather as a diagnostic exam. This may come with additional costs.
Colonoscopy
Considered the “golden standard” test for colon cancer screening; however, it is an invasive procedure. Patients will need to prep for the test with a couple of days of dietary restrictions, drinking a bowel prep the day before (and sometimes morning of) the procedure, and they will need someone to accompany them throughout the process of the procedure for transportation due to the use of sedation.
As with any procedure, there is a very limited risk of complications such as bleeding and injury to the large intestine, potentially leading to interventions such as repeat colonoscopy or rarely even surgery.
Aside from being highly effective in detecting colon cancer, any (smaller) precancerous lesions (polyps) that are detected will be removed and sent for analysis by a pathologist. This will help determine when you should have a colonoscopy repeated for screening or surveillance.
If a patient has a positive stool-based test result, what happens next?
A colonoscopy should follow to determine why the test was positive; there is currently no recommended alternative to this.
When should an individual not use stool-based testing?
If you belong to the high-risk population, stool-based testing is not recommended. Stool tests are not appropriate, and a diagnostic colonoscopy should be performed if the following symptoms are present:
- Unexplained blood in stools
- Unexplained iron deficiency anemia
- Change in stool caliber
- Unexplained weight loss
For more information about screenings and colorectal surgery at UNC Health Pardee, visit pardeehospital.org.
