Colon cancer study backs blood stool screening test
CHEAPER, LESS INVASIVE TEST PERFORMS WELL
The COLONPREV study, being conducted in Spain, is designed to compare 10-year death rates in two groups: volunteers who received a one-time colonoscopy and volunteers who are being screened every two years using fecal immunochemical testing (FIT), a form of blood stool testing. A positive FIT test led to a colonoscopy.
After the first round of testing, the researchers report in the New England Journal of Medicine, colorectal cancer was found in 30 people in the 26,703-member colonoscopy group and 33 in the 26,599-person FIT group.
What Causes Blood to Appear in Stool?
Blood may appear in the stool because of one or more of the following conditions:
- Benign (non-cancerous) or malignant (cancerous) growths or polyps of the colon.
- Hemorrhoids (swollen blood vessels near the anus and lower rectum that can rupture, causing bleeding).
- Anal fissures (splits or cracks in the lining of the anal opening).
- Intestinal infections that cause inflammation.
- Ulcers.
- Ulcerative colitis.
- Crohn’s disease.
- Diverticular disease, caused by outpouchings of the colon wall.
- Abnormalities of the blood vessels in the large intestine.
- Note that gastrointestinal bleeding may be microscopic (invisible to the eye), or may be easily seen as red blood, or black tar-like bowel movements, called melena.
Colonoscopy uncovered twice as many advanced adenomas, about two percent of the sample versus one percent.
But the chief author of the Spanish study, Enrique Quintero of Hospital Universitario de Canarias, told Reuters Health that it was encouraging that the cheaper fecal test “detected half the advanced adenomas just in the first round.”
The next round of FIT tests will uncover more growths, he predicted.
Death rates will not be examined until the 10-year follow-up is completed in 2021.
Quintero and his team also found that the people assigned to the FIT group were more likely to participate in screening than those who were in line for a colonoscopy.
The participation rates were 34 percent with the stool-sampling test compared to 25 percent for colonoscopy.
At this point in the study, the researchers concluded, “the numbers of subjects who needed to be screened to find one colorectal cancer were 191 in the colonoscopy group and 281 in the FIT group, and the numbers who needed to be screened to find any advanced (cancer) were 10 and 36.”
That’s important when the FIT test is so much cheaper than a colonoscopy, Quintero said. “This simple, non-invasive and cheap test is equally good at detecting colorectal cancer and identifying the high-risk individual that should undergo a colonoscopy.”
And the complication rate, including bleeding, low blood pressure and slow heartbeat, was nearly five times higher in the colonoscopy group.
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(Reuters Health)