Dr Graser and colleagues from Germany conducted a prospective trial designed to compare the performance characteristics of 5 different screening tests in parallel for the detection of advanced colonic neoplasia.
The research team compared CT colonography, colonoscopy, flexible sigmoidoscopy, fecal immunochemical stool testing and fecal occult blood testing.
The team assessed average risk adults provided stool specimens for faecal occult blood testing and stool testing.
|Sensitivities of colonoscopy was 100%|
The patients underwent same-day low-dose 64-multidetector row CT colonography, and colonoscopy using segmentally unblinded colonoscopy as the standard of reference.
Sensitivities and specificities were calculated for each single test, and for combinations of flexible sigmoidoscopy and stool tests.
CT colonography radiation exposure was measured, and patient comfort levels and preferences were assessed by questionnaire.
The researchers detected 221 adenomas in 307 subjects who completed CT colonography, and colonoscopy.
The team reported that 269 patients provided stool samples for both fecal occult blood testing, and stool testing.
Sensitivities of colonoscopy, CT colonography, flexible sigmoidoscopy, stool testing and fecal occult blood testing for advanced colonic neoplasia were 100%, 97%, 83%, 32%, and 20%, respectively.
Combination of flexible sigmoidoscopy with fecal occult blood testing or stool testing led to no relevant increase in sensitivity.
The research team observed that 12 of 45 advanced adenomas were smaller than 10 mm.
The team noted that 46% of patients preferred CT colonography, and 37% preferred colonoscopy.
Dr Graser’s team concluded, “High-resolution and low-dose CT colonography is feasible for colorectal cancer screening and reaches sensitivities comparable with colonoscopy for polyps larger than 5 mm.”
“For patients who refuse full bowel preparation and colonoscopy or CT colonography, flexible sigmoidoscopy should be preferred over stool tests.”
“However, in cases where stool tests are performed, stool testing should be recommended rather than fecal occult blood testing.”