colon cancer screening tests.
The new guidelines, which emphasize colon cancer prevention, come from the
American Cancer Society, the U.S. Multi-Society Task Force on Colorectal
Cancer, and the American College of Radiology.
Here's the simplest guideline: If you're age 50 or older, you need to get
routine screening for colon cancer. If you're at high risk, you may need to
start screening before 50. That recommendation isn't new, but it often goes
Beyond that, the guidelines split colon cancer tests into two groups --
tests that look inside the
bo dy and those done on stools.
Tests done inside the body can spot cancer and polyps (abnormal growths that
may develop into cancer). Stool tests primarily focus on detecting cancer, not
polyps, according to the American Cancer Society.
Here are the American Cancer Society's recommendations for both types of
Tests for Cancer and Polyps
If you're looking for a test that can spot cancer and polyps, the American
Cancer Society recommends choosing between these options:
- Flexible sigmoidoscopy every five years, or
- Colonoscopy every 10 years, or
- Double-contrast barium enema every five years, or
- "Virtual colonoscopy" (computed tomographic colonography) every
This is the first time that virtual colonoscopy has made the American Cancer
Society's list of acceptable screening tests.
If you're looking for a stool test, here are the choices recommended by the
American Cancer Society.
- Annual guaiac-based fecal occult blood test (gFOBT) with high test
sensitivity for cancer, or
- Annual fecal immunochemical test (FIT) with high sensitivity for cancer,
- Stool DNA (sDNA) test with high sensitivity for cancer (optimal interval
between tests unknown)
The American Cancer Society notes that stool tests are less likely to prevent cancer than tests that look
for cancer inside the body. Also, stool tests must be regularly repeated. And
if a stool test finds blood in stools, patients should get a colonoscopy.
About the Tests
Here is a quick look at the recommended tests:
- Flexible sigmoidoscopy: Doctors use a thin, flexible tube with a tiny
camera to examine the rectum and the lower part of the colon.
- Colonoscopy: Similar to flexible sigmoidoscopy, but includes the entire
- Double-contrast barium enema: An X-ray test used to picture the inside of
- Virtual colonoscopy: Uses CT scans to picture the inside of the
- gFOBT: Checks for blood in stool samples. If blood is found, the patient
should get a colonoscopy.
- FIT: Checks for blood in stool samples, using a different technique than
the gFOBT test. If blood is found, the patient should get a colonoscopy.
- sDNA: Checks stools for colorectal cancer DNA.
The new guidelines are posted in today's advance online edition of CA: A
Cancer Journal for Clinicians.
By Miranda Hitti
Reviewed by Louise Chang
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