Written on February 19, 2024 by Jillian Foglesong Stabile, MD, FAAFP. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Colorectal cancer is one of the most common types of cancer and cancer death.[1] You’ve probably heard a lot about different testing options for colon cancer, and you may have been wondering when to get tested for colon cancer. We’ll talk today about colon cancer and what you can do to take control of your health.
Colorectal cancer is a type of cancer that originates in the colon or rectum.[2] Cancer occurs when cells start to grow out of control. Colon cancers usually start as polyps, which are lump-like growths in the colon wall. These may take many years to turn into colon cancer, and not all polyps increase your risk of colon cancer. Adenomatous polyps and some types of sessile serrated polyps increase the risk of colon cancer, but hyperplastic and inflammatory polyps don’t increase the risk.
Several types of cancer can occur in the colon.[3] Adenocarcinoma is the most common type. This cancer starts from the cells that line the colon. Carcinoid tumors occur in hormone-producing cells in the colon. Gastrointestinal stromal tumors are rare in the colon but occur in other parts of the gastrointestinal tract. Lymphoma is a type of immune system cancer that usually starts in the lymph nodes but can also occur in the colon.
Most people who have colon cancer don’t have symptoms, but some people do. Symptoms may include: [4]
Anyone can get colon cancer, but certain factors put you at higher risk for colon cancer. These can be separated into conditions that you can control and conditions that you can’t.
Some of the factors that increase your risk for colon cancer are things that you can control. We call these modifiable risk factors. Some of these factors include [5]:
There are also risk factors for colon cancer that you can’t control. These are non-modifiable risk factors. These risk factors include [5,2]:
Previously, colon cancer screening was recommended starting at age 50. In 2021, the United States Preventative Services Task Force (USPSTF) changed the guidelines to recommend colon cancer screening starting at age 45.[2] The recommendation applies to adults age 45 or older who are at average risk for colon cancer and who don’t have any symptoms of colon cancer. Screening tests are only done when you don’t have symptoms.
If you have one of the higher-risk recommendations mentioned above, then you may need to have a colonoscopy or other colon cancer screening at an earlier age depending on your healthcare provider’s recommendation.
There are many different tests available to screen for colon cancer.[7] Which test is right for you depends on your risk factors.
Three tests involve collecting a stool sample for testing:
Flexible sigmoidoscopy is a test that looks at the lower third of your colon. It requires taking medication to prepare for the test and clean your colon out (prep). A lighted tube is put into the rectum and advanced to the junction where the transverse colon meets the sigmoid colon. The colon wall is then examined as the tube is removed. It is performed every five years or ten years if done in combination with FIT testing.
Colonoscopy is similar to flexible sigmoidoscopy but looks at the whole colon. It also requires prep and involves a flexible tube. If normal, the test is done every ten years unless a high-risk condition is present.
CT colonography is a virtual colonoscopy performed with a CT scanner. You still have to prepare for the test, similar to what you do for a colonoscopy. If normal, this test is performed every five years.
If you're interested in easy, convenient colon cancer screening, consider a FIT Colon Cancer Screening Test with at-home sample collection. This screening option is included in our at-home lab testing membership to help you take control of your health year-round.
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