Colorectal Cancer Screening

Colorectal Cancer Screening

Colorectal cancer screening - checking the large intestine and rectum for cancer, is part of overall cancer prevention. Depending on your age and risk, it may be recommended for you.

The following information is for those at average risk for colorectal cancer (CRC).

Risk Of Colorectal Cancer 

Your medical and family history determine whether you are at average or high risk for CRC. Most people are at average risk. 

If you are at average risk for CRC it means you do not have a: 

  • Personal or family history of CRC or advanced precancerous growths (advanced colon polyps)

  • Personal history of inflammatory bowel disease (ulcerative colitis, Crohn’s disease)

  • Personal or family history of a genetic disorder that increases the risk of CRC (Lynch syndrome, familial adenomatous polyposis)

If you have a high risk of CRC due to the above or other factors, your doctor will determine what screening test is best for you. They’ll recommend the appropriate age to begin testing and the proper period of time or interval between testing. Those at high risk usually start testing at a younger age and have the tests more often.

Talk with your doctor about your risk.

Screening Tests

There are two main types of screening tests, scoping and stool testing. Although rarely used, imaging may also be done.

Scoping

  • Flexible sigmoidoscopy. Use of scope to view rectum, sigmoid, and part of the descending colon.

    • Test usually done every 5 years

    • Preparation: Requires an enema for bowel preparation (prep). Need for sedation varies

    • Note: May be done alongside a Fecal immunochemical test (FIT) [see description and preparation below]

  • Screening colonoscopy. Use of scope to view the entire colon.

    • Test usually done every 10 years

    • Preparation: Requires oral solution for bowel prep. Sedation or anesthesia used during procedure.

Testing Stool Samples

  • High-sensitivity guaiac fecal occult blood test (HSgFOBT). Use of chemicals to detect blood in the stool*. Positive results require colonoscopy.

    • Test usually done every year

    • Preparation: Requires stool sample; no bowel prep needed.

  • Fecal immunochemical test (FIT). Use of antibodies to detect blood in the stool*. Positive results require colonoscopy.

    • Test usually done every year

    • Preparation: Requires stool sample and the stopping of some foods or medicines.

  • Stool DNA-FIT (sDNA-FIT). Use of biomarkers to detect cancer cells shed from the lining of the colon/rectum in the stool. Combined with the use of antibodies to detect blood in stool*. Positive results require colonoscopy.

    • Test usually done every 1-3 years**

    • Preparation: Requires stool sample; no bowel prep needed.

* Blood in stool may be a sign of colorectal cancer

** Interval depends on test manufacturer

Talk with your doctor about the options available and your preferences.

Testing Recommendations

Age

The age at which testing should begin for those at average risk varies. Depending on where you live, it ranges from age 40 to 50. In most places screening is no longer recommended after age 75. Talk with your doctor about screening beyond age 75.

Make sure you check with your doctor on the frequency of testing appropriate for you. Their recommendation may change based on your previous tests and on new research. 

Test Results

A positive result means more testing is needed - it is not a diagnosis of cancer. 

Screening for CRC is very important. Scoping may detect precancerous growths (polyps), which can be removed. If cancer is found, it allows for early treatment, such as surgery, chemotherapy, radiation, or targeted therapy.

Make sure you talk with your doctor about CRC screening. Your Goodpath coach can also provide support and answer questions.