What is Screening for Colon Polyps and Cancer?
Colon polyps and colon cancer screenings are tests performed to look for polyps or cancer in the colon of patients that have not experienced any signs or symptoms of colon polyps or cancer.
Importance of Screening for Colon Polyps and Cancer
Colon polyps and cancer screening can help prevent colon cancer by identifying precancerous lesions or growths such as colon polyps, which can be removed before they transform into cancer. Screening can also help identify cancerous lesions in the colon at an early stage when they are easier to treat.
Candidates for Screening of Colon Polyps and Cancer
Individuals that have a high risk for developing colon cancer are considered candidates for screening tests. Risk factors include:
- Being above 50 years of age
- Family history of colon cancer or polyps
- Inflammatory bowel diseases
- Certain genetic syndromes
- History of radiation to the abdomen or pelvic region
Types of Screening Tests for Colon Cancer
The different screening tests for colon cancer include:
- Stool-Based Tests: These tests involve the analysis of a stool sample.
- Guaiac-based fecal occult blood test (gFOBT): This test uses a chemical called guaiac to identify blood in the stool sample. It is recommended to be performed every year.
- Fecal immunochemical test (FIT): This test uses antibodies to identify blood in the stool. It is recommended to be performed every year.
- DNA test: This test can identify altered DNA in the stool. It is recommended to be performed every 3 years.
- Flexible Sigmoidoscopy: This test involves the insertion of a thin, lighted tube with a miniature camera through the anus to examine the rectum and the lower third of the colon. It is recommended to be performed every 5-10 years.
- Colonoscopy: This test involves the insertion of a longer, lighted tube with a miniature camera through the anus to examine the rectum and the entire colon. It is recommended to be performed every 10 years.
- CT Colonography: This test is also known as a virtual colonoscopy and involves the use of multiple X-rays and computers to produce images of the colon. It is recommended to be performed every 5 years.
Guidelines for Colon Cancer Screening
- Screening for average-risk individuals: According to the American Cancer Society, screening for colon polyps and cancer in people of average risk should begin at the age of 45 years and should continue until the age of 75 years. From the age of 75 years to 85 years, screening should be done based on overall health, life expectancy, and prior history. Screening can be discontinued after the age of 85 years.
- Screening for high-risk individuals: For people of higher-than-average risk, screening may need to begin earlier than the age of 45 years and the frequency of the tests will depend on the specific risk factors of the patient.