Screening and Surveillance in Colorectal Cancer

Colorectal cancer is the 3rd most common cancer. Lifetime risk is 1 in 20. Risk increases if a family history of colorectal cancer is present. A personal history of breast, uterine, or ovarian cancer also increases the risk for colorectal cancer. A personal or family history of colonic polyps also increases the risk. Crohn’s disease and ulcerative colitis also increase the risk.

Why screening?

In early stages colorectal cancer causes no symptoms. Early cancers can be cured up to 90%. The cancer usually starts as a polyp. These polyps can be detected by screening tests and can be removed, thus preventing transformation to cancer. Bleeding, change in bowel habits, or abdominal pain are late symptoms. In advanced stages chance for cure is less than 50%.

What are the screening tests?

Fecal occult blood testing.

Colonoscopy is the gold standard.

Flexible sigmoidoscopy allows for investigation of the distal third of the colon.

Air-contrast barium enema is done if colonoscopy cannot be done.

Virtual colonoscopy combines the CT scan images.

Recommendations: For people without any risk factors, screening starts at age 50 and should be repeated every 10 years. Another alternative is yearly stool occult blood testing with flexible sigmoidoscopy every 5 years if colonoscopy is not feasible.

People with a close relative with colorectal cancer or polyps should start screening at age 40 or 10 years before the youngest age at which a relative was diagnosed. The colonoscopy is repeated every 5 years.

Less common types of inherited colon cancer (HNPCC and FAP) may have more frequent screening beginning at earlier age.

Surveillance recommendations: If a precancerous polyp is completely removed, colonoscopy should be related every 3 to 5 years. Exam interval depends on the pathology of the removed polyp. If the polyp is not completely removed, then colonoscopy should be related in 3 to 6 months.

Colorectal cancer patients will have a colonoscopy within 1 year of the surgery. If the colon could not be examined before the surgery, then colonoscopy should be done within 3 to 5 years.

Crohn’s disease or Ulcerative colitis patients for more than 8 years should have a colonoscopy with multiple biopsies every 1 to 2 years.

(Simplified from Patient Eduction Brochures of The American Society of Colon and Rectal Surgeons)