Stool test for colorectal cancer screening: what is going on?

Given the increasing incidence of colorectal cancer (CRC), performing new and cost-effective stool tests is of particular importance for early diagnosis and treatment. In the present review, we describe the main characteristics, and the performance of the most recently developed stool tests in the screening setting of colorectal tumoral diseases. Most of the studies reported high sensitivity both for adenomas and CRC diagnosis; less than half studies reported also high specificity with respect to stage and localization of the tumor. However, the performance of every single test was extremely variable, reaching >95% specificity for most of DNA-based markers, although lacking sensitivity even in case of invasive CRC. A new potential stool marker of colon cancer is clusterin, a protein of particular interest for its high sensitivity and positive predictive value in patients with highly aggressive CRC.