There have been lots of TV and print ads about a new colon cancer screening test called Cologuard. This advertising has spurred lots of questions from my patients wondering if this colon cancer screening test was right for them.
Colon cancer has over a 90% survival rate when detected in early stages, so I support any efforts that increase participation rates in cancer screening. That being said, there are pros and cons to the Cologuard at-home test and Colonoscopy, which is considered the “gold standard” colon cancer screening exam since it is the only exam that allows your doctor the ability to identify and remove polyps. My hope is that this analysis helps to increase awareness and interest in colon cancer screening. If you have questions about any of the screening exam options, please call my office at 972-758-5484 or discuss with your doctor.
Brian K. Cooley, MD
Cologuard Testing vs Colonoscopy
WHAT IS COLOGUARD?
- DNA testing for mutations (KRAS, NDRG4, BMP3, B-Actin)
- Fecal Immunoglobulin Test (FIT) for globulin
- Not indicated for high risk (family history of colon cancer, personal history of colon polyps, IBD) or symptomatic patients
- No bowel prep
- Covered by Medicare
- Misses 8% of colorectal cancer
- Misses 60% of advanced polyps
- Cost: $500 vs FIT $22 (Medicare)
- 13% false positive rate, increases with age
- Required every 3 years, may result in patient non-compliance
- Considered a 2nd Tier test, offer only if Colonoscopy or annual FIT is refused*
- Gold standard for detection of all cancerous and precancerous lesions
- Best test for prevention of colorectal cancer and related deaths
- Covered by Medicare and less expensive than Cologuard every 3 years
- Every 10 years in average risk patients
- Only acceptable test in symptomatic patients (e.g. Iron deficiency anemia, bleeding, change in bowel habits)
- Preferred first tier according to multi-society task force on colon cancer**
- Requires bowel prep
- Operator dependent
- Sedated procedure
- Very small risk of complication
When Should I Be Screened for Colon Cancer?
Colon cancer can occur without any signs or symptoms. For this reason, Dr. Cooley recommends following the recommended American College of Gastroenterology screening guidelines:
- If you don’t have a family history of colon cancer, you should have your first colonoscopy at age 50.
- There is some recent evidence that African Americans are at higher risk of developing colon cancer at a younger age and therefore should start colon cancer screening at age 45.
- If one or more first degree relative(parent, sibling or child) has had a precancerous polyp or colon cancer, you should have your first colon examination 10 years younger than the youngest age of the family member with colon cancer, or age 40, whichever is younger.
- There are other guidelines for specific disease stateslike ulcerative colitis or Crohn’s disease that should be discussed with your doctor. Also, certain familial cancer syndrome patients need to be screened at a much younger age.