Most colon cancers develop from polyps. Preventive screenings can find polyps before they turn into cancer. People at average risk of colon cancer are recommended for screening starting at age 45. Some people may be at higher risk and need to be screened earlier:
- African Americans
- People who have close relatives with cancer
- Patients with IBD (inflammatory bowel disease)
- Certain genetic syndromes
- People with a history of colon cancer or polyps
- Lifestyle factors: obesity, smoking, heavy alcohol use, eating a lot of red meat and fatty foods
Colon Cancer: What You Need to Know
Here's a quick guide to understanding colon cancer, including symptoms, who's at risk, and steps to prevent it.
Colorectal Cancer Screening Tests: Which is right for you?
Each type of screening test has pros and cons to think about before choosing a test. Talk with your provider about which types of tests are right for you. There could also be differences in cost and insurance coverage depending on the type of test you choose. You should call your health insurer before choosing a test to understand the potential costs.
A colonoscopy is an exam that uses a small camera to look inside your colon, done at a doctor’s office or hospital. If found, polyps can be removed during the procedure. Patients are usually given a mild sedative to help relax. A colonoscopy will accurately find 85 to 95% of cancer cases in patients with cancer.
Preparation
Special diet on the day before the procedure. A laxative drink is consumed the day before to “prep” the colon so the doctor can see any polyps more easily. This will require being close to a bathroom all day.
How Often
Every 10 years if results are normal; more often if results are not normal
Special Considerations
Anesthesia or sedation is used for most patients during a colonoscopy. You will need a friend or family member to give you a ride home after the colonoscopy. You won’t be able to drive yourself. If polyps or small cancers are found during the test, they can be immediately removed. You may need colonoscopies more often in the future. There is a very small chance (Less than 1 in 500 people) of bowel perforation or a major bleed during colonoscopy.
You can do a FIT test at home by yourself. You will collect a small stool (poop) sample and then mail the test kit with your sample back to your provider or lab in 1 to 2 days. They will check the sample for blood. A FIT test will accurately find about 75 to 80% of cancer cases in patients with cancer. Over time, though, the accuracy is similar to a colonoscopy or FIT DNA test since it’s a yearly test and completed more frequently.
Preparation
None
How Often
Every year
Special Considerations
If anything unusual is found in your sample, a follow-up colonoscopy will be needed. If you do this test every year, detection of cancer is similar to that of colonoscopy, although FIT cannot find polyps as well as a colonoscopy
You can do this test at home by yourself. A FIT-DNA test will accurately find 92% of cancer cases in patients with cancer. The FIT-DNA test has more false positives (positive when there is no cancer present) than just a FIT test, so it is more likely that you will need a follow-up colonoscopy. The company that makes the FIT-DNA test will mail the test kit to your home. You will collect a whole bowel movement (poop) and then mail the test kit with the sample to a lab. It will be tested for changes in your DNA that might show cancer cells or precancerous growths.
Preparation
None
How Often
Every 3 years
Special Considerations
If anything unusual is found, a follow-up colonoscopy will be needed.
Flexible Sigmoidoscopy – During a sigmoidoscopy procedure, your doctor is able to see part of the colon and the entire rectum. The doctor will look for polyps and signs of cancer. The exam takes 10-20 minutes.
CT Colonography (Virtual Colonoscopy) – Your doctor will use x-rays and computers to get pictures of your whole colon.
Guaiac-based Fecal Occult Blood Test (gFOBT) – This test looks for blood in a stool sample that you may not be able to see for yourself. The first part of the test can be done by you in the privacy of your own home. Your doctor will give you a test kit to take home. You will use a stick to take a small stool sample. You will mail the test to your doctor or lab. The samples will be tested for blood. This test requires 3 separate samples. If anything unusual is found, your doctor may order additional tests, such as a colonoscopy.