Latest posts by Dr. Jeffrey S. Gilbert (see all)
- Cologuard: At-home test is not for everyone - January 25, 2018
- Studies linking PPIs to dementia are no need for panic - February 26, 2016
Cologuard is a stool-based colorectal screening test that received FDA approval in August 2014. This test is performed at home and detects the presence of red blood cells and DNA mutations in the stool that may indicate certain kinds of abnormal growths, such as colon cancer or polyps (precursors to cancer). In a large study comparing Cologuard with colonoscopy, the sensitivity of the test to detect colon cancer was 92%. (Sensitivity is a measure of a test’s ability to detect disease when it is truly present.)
However, it is important to know that a positive test does not automatically mean that cancer or even polyps are present. (In other words, a test can be “falsely positive.”) All positive results do need to be followed by a colonoscopy exam to clarify. Like all tests, it is also possible for Cologuard to be normal when a significant problem such as colon cancer exists. (This is known as a “false negative.”)
Currently, Cologuard is approved by the U.S. Preventive Services Task Force (USPSTF) as an option for colorectal cancer screening once every three years. Because it is considered a screening test, any colonoscopy to assess for a positive Cologuard is considered a diagnostic exam. This is important to know since many insurance plans have higher copays for diagnostic colonoscopy compared to one that is performed for screening.
Aside from being able to conduct the test at home, an appealing feature of Cologuard is the lack of needing a laxative preparation. As most people will tell you, having a colonoscopy is a breeze; preparation is the downside. However, a colonoscopy remains the gold standard for detecting colon cancer. Please don’t let a bowel prep consisting of a short-lived period of discomfort and frequent trips to the bathroom be the sole reason you do not get the most-accurate diagnosis possible.
The American Society for Gastrointestinal Endoscopy sets national standards for GI practices in detection of adenomas. This national goal is to detect and remove adenomas in 25% of colonoscopies performed. Gastrointestinal Associates surpasses that goal. Through September 2017, GIA physicians detected and removed adenomas in 45% of screening colonoscopies.
If you are still interested in Cologuard, know that it is not for everyone. The test is not appropriate for individuals who have a previous diagnosis of colon cancer or colon polyps, have a family history of colon cancer, or have a diagnosis of inflammatory bowel disease such as Crohn’s or ulcerative colitis. It is also not appropriate for patients who display symptoms suggesting a possible colon cancer.
The American Cancer Society lists these common symptoms of colon cancer, noting they often do not display until the cancer is advanced:
- Change in bowel habits, such as diarrhea, constipation or narrowing of the stool that lasts for more than a few days
- Feeling that you need to have a bowel movement that is not relieved by doing so
- Rectal bleeding
- Dark stools or blood in the stool
- Cramping or abdominal (belly) pain
- Weakness and fatigue
- Unintended weight loss
Iron deficiency anemia can also be a sign of colon cancer that needs close evaluation.
If you are 50 or older and have not yet had a screening colonoscopy, we encourage you to schedule yours today. Regardless of age, we strongly recommend a diagnostic colonoscopy if you are displaying any of the symptoms listed above. This relatively easy procedure might just save your life.
To discuss the procedure with a physician, call 865-588-5121 today to make an appointment.