Colorectal cancer: Colonoscopy is the best screening test

Aug 02, 2022

The American Cancer Society projects that 50,630 people will die from colorectal cancer in 2018. Colorectal cancer includes cancers of the colon and the rectum.

The American Cancer Society projects that 50,630 people will die from colorectal cancer in 2018. Colorectal cancer includes cancers of the colon and the rectum. This cancer is often preventable through regular screenings, with colonoscopy being the best screening test. However, for health or personal reasons, some people cannot have a colonoscopy and will require an alternate screening test.

You should talk with your doctor about when to start screening for colorectal cancer. Most people of average risk should begin screening at age 50. African Americans should begin sooner at age 45. People with certain health conditions or family history of colon cancer or polyps may also need to be screened sooner.

Why colonoscopy is the best screening test

As a gastroenterologist, I consider colonoscopy the best screening test for several reasons. A colonoscopy is the only screening test that offers a thorough examination of the entire colon. Also, a colonoscopy is the only screening test that can prevent colorectal cancer because it allows the gastroenterologist to immediately remove polyps. Removing polyps early eliminates the chance that colon cancer will develop from those pre-cancerous growths or polyps.

Alternatives to colonoscopy

If a patient cannot have a colonoscopy, then we recommend stool tests which are safe and fairly easy to do from home. Patients need to understand ahead of time that a positive result means the patient will require a colonoscopy to rule out colorectal cancer. Stool tests are not as sensitive which means you may get a false positive result (the stool test is positive, but we do not find any polyps during the colonoscopy).

There are two categories of stool tests: blood and DNA. The basic stool test checks for blood in the stool. The Cologuard test checks the stool DNA, which makes it more sensitive for detecting colon cancer and pre-cancerous polyps than the basic stool test.

Stool testing is not appropriate when a patient is symptomatic. Symptoms such as rectal bleeding or significant changes in bowel habits require a colonoscopy for further evaluation.

We generally recommend stool tests for these patients:

  1. Patients with certain health conditions: Some patients with underlying heart and lung problems may not be a good candidate for anesthesia. If those patients have no clear risk factors for colon cancer, then a noninvasive stool test would likely be the best choice.
  2. Patients who prefer not to have a colonoscopy: Some people cannot take time off from work for the bowel prep and procedure (one day). Others may have a personal objection to the bowel prep or anesthesia and decline to take the test. In this case, any type of screening is better than none, and therefore this would be a reason for a stool test.
  3. Patients over 80: The cut off age for colonoscopy depends on the health of the patient and the patient’s risk for colon cancer. We generally stop routine screening colonoscopies around the age of 80. However, if an 80 year old is generally healthy and has had pre-cancerous colon polyps in the past, then it would be reasonable to proceed with a colonoscopy.

What you need to know about Cologuard

Cologuard (the DNA stool test) is only appropriate for patients who are at average risk for colon cancer. It has not been studied nor is it recommended for patients who have had colon polyps or colon cancer in the past. It is not recommended for patients with symptoms of rectal bleeding or significant changes in bowel habits.

A positive result means the patient will then need a colonoscopy. In our practice, we have found a high rate of false positive tests with Cologuard.

There are financial concerns for some patients who have a Cologuard test followed by a colonoscopy. Insurance often will cover one colon cancer screening test, whether that is the Cologuard or a colonoscopy within a specified time frame. This varies based on carrier policies. If the patient has a positive Cologuard, then the indication for the subsequent colonoscopy is no longer screening and it becomes a diagnostic service. This often impacts how the insurance will pay for the colonoscopy. In other words, a screening colonoscopy may be covered under a wellness portion of your plan; however, a colonoscopy done after a positive Cologuard may not be. We encourage patients to call their insurance providers to confirm coverage.

Is it time for you to be screened for colon cancer? Contact Richmond Gastroenterology Associates to schedule a colonoscopy or to learn more about this important test.

Disclaimer: This blog article is intended to be informative and is not medical advice.