Evidence, Utility and Limitations of a colorectal cancer screening test in blood

Background: Detection of colorectal cancer at an early stage has been shown to significantly decrease mortality from the disease. Standard colorectal cancer screening tools include fecal occult blood tests and colonoscopy. Availability of a blood-based test for colorectal cancer has the potential to improve screening compliance.

Methods & Results: We identified a region of the Septin9 gene that is methylated in over 90% of colorectal cancer tissues with little or no methylation seen in normal colon tissue and other controls. Specific detection of colorectal cancer DNA using the Septin 9 methylation biomarker (mSEPT9) was demonstrated in multiple studies of plasma from colorectal cancer patients and colono-scopy-verified negative controls. A prospective, population-based trial to determine the clinical performance of mSEPT9 demonstrated 67% sensitivity for screen-detected colorectal cancer with 88% specificity: a new molecular diagnostic blood test for colorectal cancer based on Septin9.