When Should I Get a Colonoscopy?

There are a number of characteristics about ourselves and choices we can make that place us at a higher risk for colon cancer. As with many cancers, some of these characteristics, such as our age and gender, are not under our control. These are called non-modifiable risk factors. By knowing the risk we cannot control, one can discover the need for colon cancer tests at an earlier age. Let’s find out more about these risks and how it can change the way we think about the timing of colon cancer tests.

When we look at our risk for colon cancer and the things we cannot control; age, gender, ethnicity and family history are important factors to consider. Age is an important risk consideration because 90% of all colon cancers are diagnosed on or after the age of 50. (1) Therefore, for the average risk person, colon cancer tests should start at the age of 50. There are several tests to choose from, which we will discuss later, but let’s find out more about those who will need a colon test at an earlier age.

Gender and ethnicity are also important considerations with looking at the timing of a colon cancer tests. Men have a 25% higher chance of developing colon cancer when compared to women (2) With respect to ethnicity, African Americans are at the highest risk of developing colon cancer. Not only this, African Americans have a 20% higher chance of dying from colon cancer when compared to other ethnic groups. Furthermore, colon cancer appears to occur at an earlier age in African Americans and we are unsure of the reasons why. (3) As a result, the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy recommend that colon cancer screening begin at age 45 in African Americans and that colonoscopy is the preferred test.

Importantly, knowing your family history is essential to knowing you risk of colon cancer and when to begin testing for this disease. Having a close relative with colon cancer can more than double the risk of developing colon cancer for yourself. If you have one parent, brother or sister that had colon cancer before the age of 60, you should have a colonoscopy at the age of 40. Furthermore, if you have two or more immediate family members, such as your parents or siblings, with colon cancer at any age, you also need a colonoscopy at the age of 40. We know that colon cancer is slow growing and takes about 7 to 10 years to progress from an adenoma, which can be seen as a pre-cancer stage, to an invading cancer. Therefore, if you have a close family member with colon cancer in their 40s, you will need a coloscopy 10 years before the date your family member was diagnosed with this disease. (3) For instance, if your father had colon cancer at the age of 45, you will need a colonoscopy at the age of 35.

In all, there are a lot things that factor into the decision to get tested for colon cancer at an either age. Our age, gender, ethnicity and family history are important things to consider when deciding on the timing of colon cancer tests, but are even more risks and diseases, such as Crohn’s disease and Lynch syndrome, that can also affect the age at which you start testing for colon cancer. When looking at multiple risk, the earlier the screening the better. For instance, if you are an African American man with a father who had colon cancer at the age of 45, you need a colonoscopy at the age of 35. Starting at the age 45 in this case may be too late. As always, discuss your specific risk for colon with your doctor and find out the right time to be tested.

REFERENCES
1. “Age and Colon Cancer,” Stop Colon Cancer Now, Date accessed 5/23/21021, https://www.stopcoloncancernow.com/colon-cancer-prevention/risk-factors/age-and-colon-cancer#:~:text=Although%20any%20person%20of%20any,risk%20factor%20for%20colon%20cancer.
2. Jemal A, Siegel R, Xu J, Ward E. Cancer statistics, 2010. CA Cancer J Clin. 2010 Sep-Oct;60(5):277-300. doi: 10.3322/caac.20073. Epub 2010 Jul 7. Erratum in: CA Cancer J Clin. 2011 Mar-Apr;61(2):133-4. PMID: 20610543.
3. In Alguire, P. C., & American College of Physicians, (2018). MKSAP 18: Medical knowledge self-assessment program.