Colon cancer risk lowered, prevented with a simple screening
Dear Mayo Clinic: Are there ways to prevent colon cancer? What about early symptoms to watch for? I just turned 50, and I’ve heard colon cancer is more common as you get older. I’d like to lower my risk of getting this disease as much as possible.
A: There are some lifestyle changes that may lower your risk of developing colon cancer. But one of the most important steps you can take at your age is getting the recommended colon cancer screening. Although earlystage colon cancer rarely causes symptoms, screening exams can detect the disease early — sometimes even before it’s become cancer — when it often can be treated effectively.
Colon cancer is common, affecting about 1 in 20 people. In most cases, symptoms of colon cancer, such as persistent abdominal pain, rectal bleeding or blood in the stool, don’t appear until the disease is in its advanced stages.
Age is one of the most significant risk factors for colon cancer. Most cases are diagnosed in people older than 50. Therefore, screening begins at 50 for people with an average risk of developing colon cancer. Some people with an increased risk, such as those with a family history of colon cancer, may need to start screening sooner.
Colonoscopy is the most common colon cancer screening test. During a colonoscopy, a long, flexible tube, called a colonoscope, is inserted into the rectum. A tiny video camera at the tip of the tube allows your health care provider to detect changes or abnormalities inside the entire colon.
Other colon cancer screening tests are available, too. One is computerized tomography (CT) colonography — sometimes called a virtual colonoscopy. It uses CT imaging to produce a detailed view of the inside of the colon and rectum. It doesn’t require insertion of a scope into the colon.
Another alternative is the fecal immunochemical test. This lab test checks stool samples for microscopic amounts of blood shed from colon cancer that may not be visible to the human eye.
The newest screening option is the multitarget stool DNA test. This test looks for DNA molecules that colon cancer and polyps may shed into stool, in addition to hemoglobin. The test can be done from home and doesn’t require bowel preparation or medication restrictions.
If results from a stool DNA test, fecal immunochemical test or CT colonography are positive, a follow-up evaluation with a full colonoscopy is required.
The purpose of colon cancer screening is to detect abnormalities within the colon, such as polyps or earlystage cancers. Not all colon polyps develop into cancer, but most colon cancers begin as polyps. Promptly detecting and removing polyps significantly reduces the risk of developing colon cancer.
The results of your initial screening exam determine how often you need followup screening. In addition to getting those tests as recommended, you can take steps in your daily life to lower your risk of colon cancer.