New Test May Ease Colorectal Cancer Screening
Noninvasive Test May Encourage More Frequent Colorectal Cancer Screening
WebMD News Archive
New Option in Colorectal Cancer Screening On the Way continued...
The results showed that the stool screening test was four times more sensitive than the FOBT test in detecting invasive colorectal cancers and more than twice as sensitive in detecting precancerous growths.
Researchers say the fecal occult blood test found only 13% of colorectal cancers while the fecal DNA test found 52%, as verified by colonoscopy.
The fecal DNA testing detected 13 cancers that were missed by FOBT, while the FOBT detected one cancer that was missed by the fecal DNA test.
Researchers say FOBT testing is less accurate because it screens only for blood found in the stool that is secreted by cancerous or precancerous growths. But most cancerous growths bleed only intermittently and many precancerous growths do not bleed at all.
Previous studies have shown that precancerous and cancerous colorectal growths shed abnormal DNA, which is detectable in stool, and this test is designed to screen for those abnormalities.
Researchers say most precancerous growths that were detected by colonoscopy were not found by either test, but the stool DNA test found more of these growths than the FOBT test.
The stool DNA test has not yet been approved by the FDA for widespread use in colorectal cancer screening. But researchers say the results indicate that the test may be valuable as a more frequent screening tool to be used in combination with more accurate tests that are used infrequently, such as colonoscopy.