A stool DNA test is a relatively new approach for colon cancer screening. Instead of looking for blood in the stool (like FIT or guiac FOBT), these tests look for certain DNA mutations caused from cancerous tumors or precancerous polyps. Cells from precancerous and cancerous lesions with these mutations are often shed into the stool, where these tests may be able to detect them, therefore indicating the presence of precancerous polyps or colon cancer.
Because DNA mutations may differ between colon cancers, stool DNA tests typically target multiple markers to achieve high detection rates. Also, because DNA markers may be present in only trace quantities in stool, very sensitive laboratory methods are required. The new stool DNA tests demonstrate high detection rates of early-stage colon cancer. Unlike other noninvasive tests, the new stool DNA tests also can detect precancerous polyps.
There are currently no stool DNA tests on the market. sDNA testing has been endorsed in the past by the American Cancer Society and the U.S. Multi-Society Task Force on Colorectal Cancer but not by the U.S. Preventive Services Task Force. A next-generation stool DNA test with improved detection rates was tested in a large multicenter study and is currently being evaluated by the FDA.
For more information about sDNA, please call the Colon Cancer Alliance’s Toll-free Helpline at (877) 422-2030.