At home colon cancer screenings are often prescribed by physicians to patients who are at a low risk for developing colon cancer as an alternative to a colonoscopy. These tests are inexpensive, non-invasive, and usually are done in the comfort of a person’s home. However, if you receive a positive result from an at home colon cancer screening test you will most likely be asked to get a follow up colonoscopy to rule out the possibility that you have a polyp, precancerous adenoma, or cancerous tissue. There are guidelines that physicians use to recommend future screenings, including the timing of your next at home colon cancer test and/or colonoscopy depending on the results of your at home screening.
Stool-based tests are the most common form of at home colon cancer screening prescribed by physicians and are used to detect blood in the stool (except the multitarget stool DNA which also detects the DNA of abnormal tissue growth). If you have an abnormal result from these at home screening tests, your physician will probably ask you to follow up with a colonoscopy.
Stool-based at home colorectal cancer tests that are usually recommended by physicians include:
Patients who are low risk for colorectal cancer and whose last at home colon cancer screening had a negative result usually are able to use the following guidelines. Of course, you will discuss with your physician exactly which test is best for you and the timing of your follow up at home colon cancer screening.
High-sensitivity FOBT test – Every year
If you receive a negative result from you FOBT, this indicates the test did not detect blood in your stool sample. People at an average risk for colon cancer (no personal or family history of colon cancer) who have a negative FOBT result usually are recommended to follow up the test in one year.
FIT test – Every year
If you receive a negative result from your FIT test the typical time to repeat the test is in one year. It has a lower accuracy then the Cologuard test, 75-95% but is less expensive.
Multitarget stool DNA test – Every 1 to 3 years
The multitarget stool DNA test is known by its trade name Cologuard. This test is shown in studies to be 92% accurate. If you receive a negative result after your Cologuard test then the usual recommended time to repeat the test is every three years if you are at an average-risk for colon cancer.
When a patient receives a positive result from an at home colon cancer screening test their doctor typically will advise a follow up colonoscopy. This is an important procedure to follow through with because a colonoscopy will rule out if you have a polyp (or polyps) and confirm that you do not have colon cancer.
Regular screenings for colon cancer is the ideal way to catch colorectal cancer in its earliest stages when it is at its most preventable and treatable stage. The early stage of colon cancer usually does not present with any noticeable symptoms but can be detected with a regular screening. Further, a colonoscopy offers the physician the ability to not only detect abnormal precancerous growths (known as adenomas) but also remove the tissues before they become cancerous. While most patients who choose to get an at home colon cancer screening prefer the minimally invasive nature of the test, a colonoscopy is the only screening test that can detect and remove polyps in one appointment.
If you received a positive result from an at home colon cancer stool test be sure to discuss with your physician about any concerns you have about this result. A small percentage of people will receive a positive result in these tests, but this does not mean that you necessarily have colon cancer. Remember that it is relatively common to receive an abnormal result and it usually reveals that you have blood that is found in a stool sample. Many of these patients may have a polyp (or polyps) and following up with a colonoscopy will allow the physician to remove these small growths and test for cancerous cells.
Colorectal cancer is the third most common cancer that is diagnosed in men and women in the United States. It is also the second most common cause of death associated with cancer in both men and women.
In a recent study that involved more than 200,000 US Veterans, researchers concluded that patients who waited more than a year after an abnormal stool test had a considerably higher risk of developing colon cancer.
In a recent study that involved more than 200,000 US Veterans, researchers concluded that patients who waited more than a year after an abnormal stool test had a considerably higher risk of developing colon cancer. Important statistics from this study to consider when you receive a positive result from an home screening test include:
Your follow up colonoscopy appointment should be made soon after your positive result, ideally within 1 to 3 months. It is important to identify the cause of the positive result and minimize your risk for colon cancer. A delayed or avoided follow up colonoscopy may increase your risk for developing colon cancer if you have an unknown polyp or adenoma.
Your healthcare provider will contact you after the positive result to set up an appointment to discuss your results and your follow up options and whether or not a colonoscopy is appropriate. If you used an over the counter stool based colon cancer screening test and received a positive result, follow up with your physician to determine the validity of the finding. Lastly, make an appointment with your physician as soon as possible if you experience any of the following symptoms:
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BC Cancer Screening Writing Staff. (2021). Results. Retrieved from BC Cancer: http://www.bccancer.bc.ca/screening/colon/results
Centers for Disease Control and Prevention. (2021, February 08) Colorectal (colon) cancer: Screening tests. Retrieved from CDC: https://www.cdc.gov/cancer/colorectal/basic_info/screening/tests.htm
Cusumano, V. T., et., al. (2020, April 19). Patients without colonoscopic follow-up after abnormal fecal immunochemical tests are often unaware of the abnormal result and report several barriers to colonoscopy. BMC Gastroenterology, 20, 115. Retrieved from PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7168865/
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US Preventive Services Task Force. (2021, May 28). Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA, 325(9), 1965-1977. Retrieved from USPSTF: https://www.uspreventiveservicestaskforce.org/uspstf/document/RecommendationStatementFinal/colorectal-cancer-screening