Colorectal Cancer Screening: What’s Best For You?

According to new survey data commissioned by the Colorectal Cancer Alliance more than half of U.S. adults would rather do household chores, such as laundry and childcare, over a life-saving colorectal cancer screening. A whopping 69% say they would rather file their taxes than get a colonoscopy. While most of those surveyed understand that colonoscopies can detect cancer, 57% were unaware that these screenings can prevent colorectal cancer by removing precancerous polyps.   

The good news? For many of us, low risk and symptom-free, our dreaded screening journey can begin at home.  

The American Cancer Society lists the most common types of screening for colorectal cancer, at-home stool-based tests and visual exams. Each has their own benefits and limitations, so you and your healthcare provider can determine the best choice for you. 

Stool-based tests look at the stool (feces) for possible signs of colorectal cancer or polyps, such as the presence of blood or changes in the DNA or RNA from cells found in the stool.

The fecal immunochemical test (FIT), or immunochemical fecal occult blood test (iFOBT), checks for hidden blood in the stool. Fragile blood vessels in larger colorectal polyps or in cancers are easily damaged when stool passes through.  They can bleed into the colon or rectum, usually in amounts too small to be seen by the naked eye. 

Because vitamins and foods do not affect the test results, there are no diet restrictions or other preparations required.  

The guaiac-based fecal occult blood test (gFOBT) detects hidden blood in the stool through a chemical reaction. Unlike the FIT, some foods or drugs can affect the results of this test, so you may be instructed to avoid red meats (beef, lamb, or liver), Vitamin C and nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil), naproxen (Aleve), or aspirin before testing.

All the supplies you need for stool-based testing are provided in one package: the test cards or tubes, a wooden applicator or brush for collecting, sample bags, and a mailing envelope. 

If you choose these tests, it should be done every year, but in the privacy of your home. If the test result is positive — hidden blood is detected — you will need a colonoscopy to determine the source.  The blood may be caused by other disorders such as ulcers or hemorrhoids.

Multitargeted stool DNA or RNA tests with FIT look for specific abnormal sections of DNA or RNA from cancer or polyp cells found in the hidden blood. Colorectal cancer or polyp cells often have DNA or RNA mutations. These mutated cells often get into the stool, where tests such as Cologuard and ColoSense screen them for cellular changes.

If you choose one of these tests, it should be done every three years. There are no drug or dietary restrictions before taking the test.

Visual exams look at the inside of the colon and rectum for any abnormal areas that might be cancer or polyps.

Colonoscopy, the gold standard of screening and prevention, looks at the entire length of your colon and rectum with a colonoscope, a flexible tube with a light and small video camera on the end. During the procedure your doctor can pass instruments through the colonoscope to biopsy or remove any suspicious-looking areas such as polyps.

Some colorectal polyps are adenomas, pre-cancerous growths which may develop into cancer. If your doctor sees polyps or anything else abnormal, the entire polyp or a sample of the abnormal tissue can be removed for a biopsy and to prevent possible future cancer.

Unlike the stool-based tests, a colonoscopy requires a trip to the pharmacy for supplies and several days of preparation, including a restricted diet and laxatives to allow for a clear, clean view of the landscape!   

Colonoscopies are performed at a hospital or medical center with a light sedative. A small catheter is then used to fill your colon with air or carbon dioxide to allow for clearer images. The test usually takes about 30 minutes, but it may take longer if polyps are found and removed. If you’re like most patients, you’ll wake from a great ‘nap’ with no memory of the actual procedure. 

If you’re free of polyps, have a low-risk factor and develop no symptoms, it could be up to ten years before you’re scheduled for another procedure. Based on what is found and your medical history, your doctor will decide how often you need to be screened. 

You can see a visual animation of a colonoscopy and learn how to prepare for the procedure at the American Cancer Society’s website.   

A virtual colonoscopy is an advanced type of computed tomography (CT) scan of the colon and rectum that can show abnormal areas, like polyps or cancer. X-rays and a CT scanner are used to make 3-dimensional pictures of the inside of your colon and rectum.  While you still need to be inflated with air or carbon dioxide for clearer pictures, a virtual colonoscopy doesn’t require sedation or a scope to be put into the rectum or colon.

For people who can’t or don’t want to have an invasive test such as a colonoscopy the scan can be done quickly, but it requires the same type of bowel prep as a colonoscopy and, if polyps or other suspicious areas are discovered, a colonoscopy will still be needed to remove or biopsy them. 

So, what is right for you? Discuss your risk factors with your healthcare provider and check with your insurance provider regarding coverage of at-home tests and any follow-up procedures. The American Cancer Society offers colorectal cancer screening guidelines for people at average risk as well people at high risk for colorectal cancer.

Screening saves lives. When colorectal cancer is diagnosed at the localized stage, the five-year survival rate is 91%.