Colorectal Cancer Screenings and Early Detection

Colorectal cancer can be very sneaky, appearing in your body with no signs or symptoms. For this reason it is important for people over 50 to be screened for colorectal cancer. Screening tests allow doctors to spot the disease at an early, curable stage. Screenings also help prevent cancer by finding polyps that can be removed before they become cancerous.

Screenings
The American Cancer Society recommends colorectal cancer screenings begin at age 50. The main tests include the fecal occult blood test to detect any blood in your stool; a flexible sigmoidoscopy, which examines your rectum and the lower part of your colon for polyps or tumors; and a colonoscopy, allowing your doctor to see your entire colon. If he or she finds something suspicious during any of these screening exams, you will most likely have more tests to help rule out or confirm a diagnosis. Your doctor will biopsy and/or remove any polyps and may order a blood test called a CEA assay to measure carcinoembryonic antigen, a protein that is sometimes present in higher levels in patients with colorectal cancer.

Screening innovations
New tests for colorectal cancer screening are under study. For example, virtual colonoscopy (also called computed tomographic colonography) uses special X-ray equipment to take pictures of the colon. A computer then assembles these pictures into detailed images that show polyps and other abnormalities. Virtual colonoscopy may cause less discomfort and take less time than conventional colonoscopy; it is less invasive and does not require sedating medication. However, your doctor cannot remove polyps or do a biopsy during a virtual colonoscopy.

More information on colorectal cancer prevention:

• Risk factors
• Assessing your risk
• Screening and early detection
• Signs and symptoms  
• Gastrointestinal Cancer Prevention Program
• Web resources

March 2008