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COLORECTAL CANCER SCREENING
What is colorectal cancer?
Colorectal (large bowel) cancer is a disease in which malignant (cancer) cells form in the inner lining of the colon or rectum. Together, the colon and rectum make up the large bowel or large intestine. Most colon and rectal cancers originate from benign wart-like growths on the inner lining of the colon or rectum called polyps.
How common is colorectal cancer?
Colorectal cancer is the second most common cancer killer overall and third most common cause of cancer-related death in the United States in both males and females.
What is screening for colorectal cancer?
Screening means looking for cancer or polyps when patients have no symptoms. Finding colorectal cancer before symptoms develop dramatically improves the chance of survival. Identifying and removing polyps before they become cancerous actually prevents the development of colorectal cancer.
Who is at risk for colorectal cancer?
- Everyone age 50 and older.
- Anyone with a family history of colorectal cancer.
What are the symptoms of colorectal cancer?
Symptoms of colorectal cancer vary depending on the location of the cancer within the colon or rectum, though there may be no symptoms at all.
Why should you get checked for colorectal cancer even if you have no symptoms?
Adenomas can grow for years and transform into cancer without producing any symptoms. By the time symptoms develop, it is often too late to cure the cancer, because it may have spread. Screening identifies cancers earlier and actually results in cancer prevention when it leads to removal of adenomas (pre-cancerous polyps).
What tests are available for screening?
Several options are available for screening average-risk persons.
- Fecal occult blood test. (Stool cards)
One of the presentations of colon cancer is chronic blood loss in the stool. Sometimes, such blood loss is so minimal, it cannot be
seen when the stool is inspected in the toilet. You will be asked to place a small stool sample on a special card which is returned
to the doctor or lab to test for occult (hidden) blood. This test is done annually. If the test is positive, colonoscopy should be
done. This option is not as good as getting a colonoscopy and the results are not always predictive of presence or absence of colon
cancer.
- Double contrast barium enema (DCBE).
Barium is a white liquid that helps to show the inside image of the colon and rectum on an X-ray. The liquid barium is put into the colon using a rectal tube. Multiple X-rays are taken to look for polyps or cancers. DCBE is less expensive than colonoscopy but also less effective. DCBE has not been established as a reliable colorectal cancer screening test in any rigorous scientific studies.
- Sigmoidoscopy.
An examination in which a doctor uses a sigmoidoscope (a thin, lighted instrument) to view the inside of the lower colon and rectum (usually about the lower 2 feet) for polyps and cancers. If an adenoma is found, colonoscopy should be performed. Sigmoidoscopy does not examine the entire colon and so is less reliable than colonoscopy for detecting polyps. Sigmoidoscopy is performed every 5 years, often in conjunction with an annual fecal occult blood test.
- Colonoscopy.
A doctor can examine your entire colon and rectum during colonoscopy. The procedure is used to look for early signs of cancer in the colon and rectum where they could not be reached by Sigmoidoscopy. Polyps can be removed during colonoscopy. Sedation is usually used for colonoscopy. Colonoscopy is currently the only test recommended for colorectal cancer screening in average-risk persons at 10 year intervals.
- Computerized topographic (CT) colonography and magnetic resonance (MR) colonography.
These tests are sometimes called "Virtual Colonoscopy". These two tests are fairly new methods that allow your doctor to look for colorectal polyps and cancers. Virtual Colonoscopy is a recently developed technique that uses a CT scanner (CT colonography) or Magnetic Resonance scanner (MR colonography) along with computer-assisted software to look inside the body without having to insert a long colonoscope into the colon or without having to fill the colon with liquid barium. These two tests are performed by radiologists. They are still in development, have not been established as reliable screening tests, and have not been endorsed for colorectal cancer screening.
What can I do to prevent the development of colorectal cancer?
- The strategy for reducing colorectal cancer deaths is simple.
- For normal risk individuals, screening tests begin at age 50 and the preferred approach is a screening colonoscopy every 10 years; an alternate strategy consists of annual stool test for blood and a flexible sigmoidoscopic exam every 3 to 5 years.
- Colonoscopic surveillance (also called screening colonoscopy) needs to be at more frequent intervals for individuals at high risk for colon cancer (for instance, those with a personal history of colorectal cancer or adenomatous polyps; family history of colorectal cancer; non-hereditary polyposis; colorectal cancer; or a pre-disposing condition such as inflammatory bowel disease.
- For both average and high risk individuals, all potential pre-cancerous polyps must be removed.
- Recent observations suggest regular use of non-steroidal anti-inflammatory drugs or aspirin, reduce the chances of colorectal cancer death by 30-50%. These drugs also have risks, particularly intestinal bleeding, and patients should consult their physician as to whether regular use of these agents is appropriate.
- Folate, and calcium, have a modest protective benefit against colon cancer.
- A high fiber (vegetables) and low fat diet, regular exercise, maintenance of normal body weight.
- Cessation of smoking is also beneficial.
I recommend colonoscopy over all other tests to screen for cancer. It is helpful in detecting cancer and preventing disability
and death from colon cancer.
Please call my office and we would set you up with a physician who performs this test.
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