Colon cancer is the third most common cancer in men and women. The American Cancer Society estimates that more than 153,000 people will be diagnosed with the condition and more than 52,000 will die from it in 2023 alone, as many as 13% of them under the age of 50. Due to the rising rates of colon cancer in younger adults, the U.S. Preventive Services Task Force decreased the recommended age for colon cancer screening from 50 to 45 back in 2021. Medicare has finally caught up and will cover screening for this age group as well. They have also changed how they cover screening and diagnostic colonoscopies.

Stool-Based Studies

These tests are an easy, non-invasive way to screen for colon cancer. All it takes is a stool sample to see if you are at risk. As of January 1, 2023, you are eligible for the following screening tests if you are 45 and older.

Sensitivity:
The ability of a test to detect a disease in someone who actually has the disease, i.e., a true positive. A test with a low sensitivity will have more false positives.

Specificity:
The ability of a test to detect the absence of disease in someone who does not have it, i.e., a true negative. A test with a low specificity with have more false negatives.

Guaiac-based Fecal Occult Blood Test (gFOBT)

• What: The study uses an enzyme to test for blood in the stool.
• Number of stool samples needed: 3
• Diet changes: To decrease the risk for a false positive, you should not eat raw fruit/vegetables or red meat 3 days before the test. You should also refrain from using anti-inflammatories (i.e., ibuprofen, naproxen, etc.), iron supplements, or vitamin C supplements 3 days before the test.
• Frequency: Every year
• Accuracy: Sensitivity 12.9 – 79.4%, specificity 86.7 – 97.7%

Immunoassay-based Fecal Occult Blood Test (iFOBT), aka Fecal Immunochemical test (FIT)

• What: Antibodies are used to detect hemoglobin in the stool.
• Number of stool samples needed: 1
• Diet changes: None needed
• Frequency: Every year
• Accuracy: Sensitivity 73.8%, specificity 94.9%

Multi-target Stool DNA (sDNA) Test – The Cologuard™

• What: The study looks for abnormal DNA that is shed in the stool.
• Who: Only people at low or average risk qualify for coverage
• Diet changes: None needed
• Frequency: Once every 3 years
• Accuracy: Sensitivity 92.3%, specificity 86.6%

If any of these tests have a positive result, it does not mean you have cancer. You will need to follow-up with another test to investigate further.

Visualization of the Colon

The best way to screen for colon cancer is to get a direct look at the colon and if needed, to get a tissue sample of the colon by way of a biopsy. The following tests are covered by Medicare and are performed for people 45 and older. You will need to complete a bowel prep before each of these procedures.

Colonoscopy

• What: A flexible narrow tube with a camera and light on the end is inserted into the rectal and used to visualize the colon. The camera will scan the full length of the colon looking for abnormalities.
• Frequency: Every 24 months if you are considered at high risk for colon cancer -or- Every 120 months if you are at average risk -or- 48 months after a flexible sigmoidoscopy

Screening colonoscopy:
A colonoscopy that is performed in response to an abnormal stool-based colon cancer screening study will be free to you.

Flexible Sigmoidoscopy

• What: A flexible narrow tube with a camera and light on the end is inserted into the rectal and used to visualize the colon. The camera will scan the lower part of the colon (the rectum, sigmoid colon, and descending colon) looking for abnormalities.
• Frequency: Every 48 months if you are at low risk -or- 120 months after a flexible sigmoidoscopy

Diagnostic colonoscopies and flexible sigmoidoscopies:
A screening colonoscopy (or flexible sigmoidoscopy) that detects a polyp or other abnormality during the procedure will be converted to a diagnostic colonoscopy (or flexible sigmoidoscopy). The test will no longer be free to you. You will pay a 15% coinsurance but will not need to pay toward your deductible.

Barium Enema (Lower GI Series)

• What: A sample of barium (a contrast dye used for radiographs) is inserted into the rectum via a tube. The dye coats the colon. An X-ray is then taken to look for any irregularities in the bowel.
• Frequency: Every 48 months if you are at low risk for colon cancer -or- Every 24 months if you at high risk for colon cancer

Costs:
Unlike the other colon cancer screening tests, a barium enema is not free. You will pay a 20% coinsurance for it but will not need to pay toward your deductible.

Blood-Based Studies

Not everyone wants to handle a stool sample and many prefer to skip a colonoscopy, even though it is considered the gold standard. In those cases, Medicare may offer another screening option in the future — blood-based biomarker tests. Yes, a simple blood test may one day screen for colon cancer.

To qualify for coverage in the future, a test must have the following:

FDA approval for colon cancer screening

Sensitivity >/= 74%, specificity >/= 90%

A recommendation or consensus statement from the U.S. Preventive Services Task Force or at least one professional society

At the preset time, there is only one FDA-approved blood-based biomarker test for colon cancer, the Epi proColon® test, but Medicare does not cover it. That’s because it’s sensitivity and specificity are only 68.2 – 72.2% and 80.0 – 80.8% respectively. There are several tests still under investigation.

 

Article – Billing and Coding: MolDx: SEPT9 Gene Test (A54300). (2019). CMS.gov. https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=54300

Blood-Based Colorectal Cancer Screening Coverage. Medicare.gov. https://www.medicare.gov/coverage/colorectal-cancer-blood-based-biomarker-screenings

Epi proColon. Epigenomics. https://www.epiprocolon.com/wp-content/uploads/sites/3/2017/06/MKT_0026_Physician_messaging_and_brochure_rev5.pdf

NCA – Screening for Colorectal Cancer – Blood-Based Biomarker Tests (CAG-00454N) – Decision Memo. (2023). Cms.gov. https://www.cms.gov/medicare-coverage-database/view/ncacal-decision-memo.aspx?proposed=N&NCAId=299

Recommendation: Colorectal Cancer: Screening. (2021). United States Preventive Services Taskforce https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening

Removal of a National Coverage Determination & Expansion of Coverage of Colorectal Cancer Screening Action Needed. (2023). MLN Matters Number: MM13017. Centers for Medicare & Medicaid Services. https://www.cms.gov/files/document/mm13017-removal-national-coverage-determination-expansion-coverage-colorectal-cancer-screening.pdf

Siegel, R. L., Wagle, N. S., Cercek, A., Smith, R. A., & Jemal, A. (2023). Colorectal cancer statistics, 2023. CA: A Cancer Journal for Clinicians. https://doi.org/10.3322/caac.21772

Song, L.-L., & Li, Y.-M. (2016). Current noninvasive tests for colorectal cancer screening: An overview of colorectal cancer screening tests. World Journal of Gastrointestinal Oncology, 8(11), 793. https://doi.org/10.4251/wjgo.v8.i11.793