Colon Cancer Prevention

By: Dorinda Rouch, M.D.

After celebrating my 50th birthday this year, I soon found myself staring at the box of prep solution for my screening colonoscopy. What seemed like a good idea when suggested by my primary care provider now seemed like self-inflicted suffering. I began asking myself….

Why do I need to do the screening?
Most colon cancers can be prevented or detected early with screening. Most colon cancers arise from benign (non-cancerous) polyps that become cancer over a period of years. Most polyps can be removed at the time of colonoscopy. If a colon cancer is found at an early stage, it can be cured with surgery. Screening has decreased the rate of deaths from colon cancer by 50% over the last few decades.

Why start screening at 50?
The chance of being diagnosed with colon cancer starts to increase somewhere between ages 45-50, with 90% of colon cancers occurring after age 50. Some people have risk factors that may alter the recommendation to start at age 50. These include a personal or family history of colon cancer or polyps, history of inflammatory bowel disease, history of pelvic radiation, or history of endometrial cancer before age 50.

What are other risk factors?
Other risk factors include obesity, diabetes mellitus, consuming red and processed meat, cigarette smoking and drinking more than 2 alcoholic beverages daily. A free online assessment tool is available at www.cancer.gov

How can I reduce my risk of colon cancer?
Studies have shown up to 27 percent reduction in colon cancer risk when comparing the most with the least active individuals. Eating a diet with high fiber and plenty of fresh fruit and vegetables may reduce the risk of colon cancer. Vitamin D, calcium and magnesium supplementation may decrease the risk as well. Daily use of aspirin and other drugs like aspirin may have a protective effect.

But why a colonoscopy? Aren't there other screening tests?
Colonoscopy allows the doctor to see the colon directly and remove suspicious findings at the time of the test. If there are no polyps at the time of colonoscopy, screening is done every 10 years. Other tests that directly look at the colon include CT colonography (screening interval of every 5 years) and flexible sigmoidoscopy (screening interval of every 5 years). Stool-based tests include an annual fecal-based immunochemical test (FIT) which screens for hidden blood in the stool or a FIT-DNA test which can be done every 3 years and looks for hidden blood and DNA from colon cancer and polyps. Guaiac-based stool tests and barium enemas are not recommended for screening.

When can I stop screening?
Talk to your primary doctor, but in general, screening can stop between the ages of 75-85 depending on other medical conditions.

In the end, when I had answered all of my doubt-filled questions, I decided to swallow my fear. "Bottoms up!" I toasted to the fact that I was making a positive and proactive health decision.