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Early detection in vital - over 80% of all cases of colon cancer could be prevented with recommended screening.

Despite its high incidence, colorectal cancer is one of the most detectable and, if found early enough, most treatable forms of cancer. Over 90% of those diagnosed while the cancer is still localized survive more than five years. Currently, however, only 37% of colorectal cancers are detected while still localized.

Colorectal cancer can be present in people without symptoms, known family history, or predisposing conditions, such as inflammatory bowel disease. Regular screening will help identify pre-cancerous polyps and colorectal cancers earlier.

The Harvard Center for Cancer Prevention recently reported that regular screening, combined with a healthy lifestyle, can prevent over half of all colon cancer deaths in the United States. Primary prevention through polypectomy, or the removal of polyps, substantially reduces the risk of developing colorectal cancer.

Survival Rates

Screening FAQ

How does screening save lives?
Screening for colorectal cancer works in two ways: first, by finding cancers early when treatment is most effective; second, by finding growths (polyps) inside the colon and removing them before they become cancer; and second, by finding cancers early when treatment is most effective.

If screening works, why aren't more people doing it?
Screening compliance rates are influenced by many factors, not least of which are:

lack of public awareness about colorectal cancer and of the benefits of regular screening
inconsistent promotion of screening by medical care providers
uncertainty among insurance providers and consumers about insurance benefits and limitations on covered benefits
characteristics of the screening procedures (e.g., imperfect tests, negative attitudes towards the screening procedures)
absence of social support for openly discussing and doing something about "the disease down there"

What are the types of colon polyps?
There are 4 types of polyps that commonly occur within the colon:

Inflammatory - Most often found in patients with ulcerative colitis or Crohn's disease. Often called "pseudopolyps" (false polyps), they are not true polyps, but just a reaction to chronic inflammation of the colon wall. They are not the type that turns to cancer. They are usually biopsied to verify type.
Hyperplastic - A common type of polyp which is usually very small and often found in the rectum. They are considered to be low risk for cancer.
Tubular adenoma or adenomatous polyp - This is the most common type of polyp and the one referred to most often when a doctor speaks of colon polyps. About 70% of polyps removed are of this type. Adenomas carry a definite cancer risk which rises as the polyp grows larger. Adenomatous polyps usually cause no symptoms, but if detected early they can be removed during colonoscopy before any cancer cells form. The good news is that polyps grow slowly and may take years to turn into cancer. Patients with a history of adenomatous polyps must be periodically reexamined.
Villous adenoma or tubulovillous adenomas - About 15% of polyps removed are of this type. These are the most serious type of polyp with a very high cancer risk as they grow larger. Often these are sessile and not on a stem making removal more difficult. Smaller ones can be removed in piecemeal fashion--sometimes over several colonoscopies. Larger sessile villous adenomas may require surgery for complete removal. Follow up depends on size and completeness of removal.

Why remove polyps if they are benign?
Colon polyps are important, since some may turn into colon cancer over time. While not every colon polyp turns to cancer, it is felt that almost every colon cancer begins as a small non-cancerous polyp. Fortunately, during colonoscopy these polyps can be identified and removed or destroyed--thus preventing a possible colon cancer. If a polyp is large enough, tissue can be retrieved and sent for biopsy to determine the exact type of polyp.

What are my options for screening?
Professional guidelines emphasize the importance of a regular screening program that includes annual fecal occult blood tests (FOBT), periodic partial or full colon exams, or both. Leaders in the field have estimated that, with widespread adoption of these screening practices, as many as 30,000 lives could be saved each year. Read below for more information about screening methods and guidelines.

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Screening Methods

The following options are acceptable choices for colorectal cancer screening in average-risk adults. These tests as well as others are also used when people have symptoms of colorectal cancer and other digestive diseases. Since each of the following tests has inherent characteristics related to accuracy, prevention potential, costs, and risks, individuals should have an opportunity to make an informed decision when choosing a screening test.

Screening Method	Advantages	Disadvantages
FOBT	Inexpensive; covered by most insurance Simple to complete Strong evidence from randomized controlled trials of reduction in mortality with screening	Requires patient action for completion of test (restricted diet and stool collection) Patients may find test unpleasant to do High false positive rate
Flexible sigmoidoscopy	Moderate cost; covered by most insurance Many primary care providers can do the test in their office 5 year screening interval Evidence from case-control studies of reduction in mortality with screening	Requires enema preparation Patients may find test uncomfortable or embarrassing Small risk of perforation or bleeding Screens only about half the colon
Double contrast barium enema	Screens full colon 5 or 10 year screening interval	Requires laxative preparation Patients may find test uncomfortable or embarrassing May be covered as a screening test in place of sigmoidoscopy
Colonsocopy	Screens full colon 10 year screening interval Evidence for reduction in mortality with screening, from follow-up of patients with adenomatous polyps Sedation given to patient to minimize discomfort	Typically requires 2-days of clear liquids & laxative preparation Patients may find test uncomfortable or embarrassing Small risk of perforation or bleeding Usually not covered as a screening test for patients of average risk

Additional Screening Tools:

DNA-based Stool Test:
This test examines DNA taken from a stool sample, looking for genetic defects that could indicate the presence of pre-cancerous polyps or colorectal cancer. This test is obtained from a physician, and the sample collection can be done in the privacy of your home with no advance preparation or dietary restrictions. The test is non-invasive, painless and easy to administer. It involves placing a container over the toilet to collect the bowel movement and sending the sealed container to a medical lab for analysis. If something abnormal is detected, a traditional colonoscopy is usually required for further examination. Final studies are being completed to determine the test's accuracy; early results indicate the test is likely to be highly accurate.

Virtual Colonoscopy:
Sometimes called a computed tomography colography, this is a non-invasive procedure, meaning the screening is done completely outside the body. A virtual colonoscopy requires the same advance preparation as a standard colonoscopy. During the virtual colonoscopy procedure, the physician inserts a small tube into the rectum to fill the colon with air. Then, instead of inserting a colonoscope into the rectum and through the colon like in a traditional colonoscopy, the physician uses MRI or CT scan technology to examine the colon from outside the body. The physician then carefully analyzes these images. If an abnormality is found, a traditional colonoscopy is required for further examination. This less invasive method of screening for colon cancer could become more common, if results from a newly published clinical trial are proven by further research. Doctors from the National Naval Medical Center report in the New England Journal of Medicine (Vol. 349, No. 23: 2191-2200) that virtual colonoscopy using computed tomography (CT) scans was just as effective as traditional optical colonoscopy at finding precancerous polyps in people at average risk of colon cancer.

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Screening Guidelines

American Cancer Society Guidelines on Screening and Surveillance for the Early Detection of Colorectal Adenomas and Cancer — Average-Risk Women and Men Ages 50 and Older

The following options are acceptable choices for colorectal cancer screening in average-risk adults. Since each of the following tests has inherent characteristics related to accuracy, prevention potential, costs, and risks, individuals should have an opportunity to make an informed decision when choosing a screening test.

Test	Interval (beginning at age 50)	Comment
Fecal Occult Blood Test (FOBT) & Flexible Sigmoidoscopy	FOBT annually and flexible sigmoidoscopy every 5 years	Flexible sigmoidoscopy together with FOBT is preferred compared with FOBT or flexible sigmoidoscopy alone. All positive tests should be followed up with colonoscopy.*
Flexible sigmoidoscopy	Every 5 years	All positive tests should be followed up with colonoscopy.*
Fecal Occult Blood Test	Yearly	The recommended take-home multiple sample method should be used. All positive tests should be followed up with colonoscopy., *
Colonsocopy	Every 10 years	Colonoscopy provides an opportunity to visualize, sample and/or remove significant lesions.
Double Contrast Barium Enema (DCBE)	Every 5 years	All positive tests should be followed up with colonoscopy

American Cancer Society Guidelines on Screening and Surveillance for the Early Detection of Colorectal Adenomas and Cancer — Women and Men at Increased Risk or at High Risk

Risk Category	Age to Begin	Recommendation	Comments
INCREASED RISK
People with a single, small (< 1 cm) adenoma	3-6 years after the initial polypectomy	Colonoscopy*	If the exam is normal, the patient can thereafter be screened as per average risk guidelines.
People with a large (1 cm +) adenoma, multiple adenomas, or adenomas with high-grade dysplasia or villous change.	Within 3 years after the initial polypectomy	Colonoscopy*	If normal, repeat examination in 3 years; If normal then, the patient can thereafter be screened as per average risk guidelines.
Personal history of curative-intent resection of colorectal cancer	Within 1 year after cancer resection	Colonoscopy*	If normal, repeat examination in 3 years; If normal then, repeat examination every 5 years.
Either colorectal cancer or adenomatous polyps, in any first-degree relative before age 60, or in two or more first-degree relatives at any age (if not a hereditary syndrome).	Age 40, or 10 years before the youngest case in the immediate family	Colonoscopy*	Every 5-10 years. Colorectal cancer in relatives more distant than first-degree does not increase risk substantially above the average risk group.
African Americans	Age 45	Colonoscopy*	The guidelines were lowered due to earlier age of diagnosis as well as higher death rate from colorectal cancer in African Americans as compared with whites. The guidelines also state the need for colonoscopy as "first-line" screening procedure due to African Americans having more right-sided colon cancers and polyps.
HIGH RISK
Family history of familial adenomatous polyposis (FAP)	Puberty	Early surveillance with endoscopy, and counseling to consider genetic testing	If the genetic test is positive, colectomy is indicated. These patients are best referred to a center with experience in the management of FAP.
Family history of hereditary non-polyposis colon cancer (HNPCC)	Age 21	Colonoscopy and counseling to consider genetic testing	If the genetic test is positive or if the patient has not had genetic testing, every 1-2 years until age 40, then annually. These patients are best referred to a center with experience in the management of HNPCC.
Inflammatory bowel disease Chronic ulcerative colitis Crohn's disease	Cancer risk begins to be significant 8 years after the onset of pancolitis, or 12-15 years after the onset of left-sided colitis	Colonoscopy with biopsies for dysplasia	Every 1-2 years. These patients are best referred to a center with experience in the surveillance and management of inflammatory bowel disease.

*If colonoscopy is unavailable, not feasible, or not desired by the patient, double contrast barium enema alone, or the combination of flexible sigmoidoscopy and double contrast barium enema are acceptable alternatives. Adding flexible sigmoidoscopy to DCBE may provide a more comprehensive diagnostic evaluation than DCBE alone in finding significant lesions. A supplementary DCBE may be needed if a colonoscopic exam fails to reach the cecum, and a supplementary colonoscopy may be needed if a DCBE identifies a possible lesion, or does not adequately visualize the entire colorectum.

**There is no justification for repeating FOBT in response to an initial positive finding. American Cancer Society Guidelines on Screening and Surveillance for the Early Detection of Colorectal Adenomas and Cancer — Women and Men at Increased Risk or at High Risk

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Screening FAQ

Screening Methods

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Screening Guidelines

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