Colorectal cancer (CRC) is common—even in people who have no history of the disease in their family. In many cases, CRC does not cause bleeding or other symptoms until it is in a late stage that is difficult to cure. For these reasons, prevention is key.
Typically, CRC starts as a small precancerous growth which takes years to become a true cancer. Discovery and removal of precancerous growths, or polyps, often prevent cancer from developing. If you follow your doctor’s advice and have proper screening, your chance of getting colon cancer is likely to decline significantly.
Screening Options
There are several options for CRC screening. None of the options is perfect in all aspects and the various screening tests differ in accuracy, safety, convenience, availability and cost.
MAGIC follows the US National Guidelines for colorectal cancer screening. These guidelines are set by representatives from the American Cancer Society, the US Multi-Society Task Force and the American College of Radiology. The following tests are included in these guidelines and are offered by MAGIC:
- Traditional (Optical) Colonoscopy
- Integrated CT Colonography (Virtual Colonoscopy with same day polyp removal if polyp is found—15% chance of polyp for patients at average risk)
- Fecal Occult Testing (Stool test for blood)
- Fecal DNA Testing (Stool genetic test for cancer)
- Flexible sigmoidoscopy
Advantages and Disadvantages of CRC Screening Tests
Optical (Traditional) Colonoscopy
Advantages
- Highly Accurate
- Polyps removed same day (during test)
Disadvantages
- Requires prep
- No driving until day after test
- There are known risks
- Requires IV and sedatives/anesthesia
Integrated CT Colonography (Virtual Colonoscopy)
Advantages
- Highly Accurate
- Covered by most insurers
- No known risk
- No IV or sedative are required
- No driving restrictions
- Noninvasive
- Average test time 10 min (in scanner)
- Polyps can be removed same day (*)
- Important findings outside the colon may be discovered
*Polyps are found in approximately 15% of patients who are at average risk for CRC. If polyps are found, patients are offered same day colonoscopy if medically cleared.
Disadvantages
- Requires prep
- Medicare does not yet always cover
- Findings outside the colon may be discovered, requiring additional tests
Stool Test for Blood
Advantages
- Can be done at home
- Low cost
- No prep required
Disadvantages
- Colon is not visualized
- Test cannot determine whether polyps or cancer exist
Stool DNA Test (Cologuard)
Advantages
- Can be done at home
- No prep required
Disadvantages
- Colon is not visualized
- Detects cancer but not precancerous polyps
- Not all insurers cover
- False positives can occur
Flexible Sigmoidoscopy
Advantages
- Less aggressive prep
- Can be done without sedation
Disadvantages
- Entire colon is not visualized
- Frequently misses growths