Genetic Test Evaluation

understanding how genetic tests impact patient management

Cologuard (Exact Sciences Corp.)

December 5, 2017

Fecal-based colorectal cancer (CRC) screening tests have been used to detect hemoglobin, a measure of fecal occult blood (FOB), in stool, which is a nonspecific sign of CRC. In general, fecal-based CRC screening is a tool to improve CRC detection without the inconvenience (i.e., bowel preparation and time commitment) of screening colonoscopy or other invasive methods. Fecal-based assessment can also include the analysis of DNA found in the stool, detecting alterations that may occur during CRC carcinogenesis from cells that are shed into the stool. Stool-based tests using DNA biomarkers plus FOB screening are presumed to detect more CRCs than FOB alone. This report reviews the Cologuard (Exact Sciences Corp.) combination cancer screening test.