Monday, January 26, 2015
Is Colon Cancer Related to Genetics?
Hi: I am a healthy guy who just turned 50; my father had colon cancer at age 40 and my mother got it when she was 51. Both had surgery and neither died from colon cancer. Both of them died from unrelated causes. My question: do I have a significantly increased risk of colon cancer? I ignored this question since neither parent actually died from the disease....from what I have read online, I guess that I could have been screened at age 40, so I`m way past that with no symptoms. I have had little if any preventative medical care, but I just got a PCP and she wants to schedule a colonoscopy ASAP. Is this reasonable? Thanks.
Your doctor’s recommendation for a colonoscopy is very reasonable, and I encourage you to follow her advice. Generally when people have a family member with colon cancer diagnosed between ages 50 and 60, we recommend that colon cancer screening start at age 40 and be repeated every 5 years. For a family history of colon cancer at 40, we would recommend that screening start at age 30 (10 years prior to the earliest colon cancer diagnosis) and this should be repeated every 3-5 years. Even though you don’t have any symptoms, you could have polyps which could develop into colon cancer. Removing polyps early has been shown to reduce the chance of developing colon cancer, so not only is screening good for early detection, it’s also good for risk reduction.
Now, considering that your father was so young when he was diagnosed, you should also think about the possibility that this could be a hereditary form of colon cancer, and you might be at substantially higher risk for colon cancer than most people your age. If you have a hereditary form of colon cancer more frequent screening may be recommended (possibly as frequently as every 1-2 years). You can contact a genetics center in your area and speak with a genetic counselor to review your family history and discuss the optimum level of screening and the possibility of genetic testing. You can find a genetics center in your geographic area by visiting the website of the National Society of Genetic Counselors. You can get more information on colon cancer by visiting the National Cancer Institute. You can also get more information about hereditary colon cancer at the following link:
Duane D Culler, PhD, MS
Clinical Instructor of Genetics
School of Medicine
Case Western Reserve University