Septin-9: a novel biomarker for colorectal cancer screening

Abstract

Background: The gold standard method for the diagnosis of colorectal cancer is colonoscopy. However, colonoscopy has several limitations and complications. Moreover, fecal occult blood test and serum based tumor markers do lack the desired specificity and sensitivity. Therefore, a novel biomarker is needed for early detection of colorectal cancer. With this prospective randomised controlled study author’s aim was to evaluate the efficacy of Septin-9 on colorectal cancer screening.Methods: Septin-9 is a protein which is encoded by the SEPT9 gene. SEPT9 has been detected in the blood of colorectal cancer patients. In this study, the results of fecal occult blood test, carcinoembryonic antigen and SEPT9 using fecal and blood samples of the patients obtained before colonoscopy were compared. DNA isolation and bisulfite transformation were made from the blood samples for SEPT9. The experimental and control groups were built up using the results of biopsy taken during colonoscopy.Results: Fecal occult blood test was determined as positive in control group for 30% (6/20), in colorectal cancer group for 54.2% (13/24). FOBT specificity and sensitivity for colorectal cancer were 54.1%, 70%, respectively. Sensitivity and specificity of Septin9 at detecting colorectal cancers were found statistically significant according to either fecal occult blood test or carcinoembryonic antigen values.Conclusions: When author evaluated their situation in the light of the data, it was seen that CRCs is an important public health problem. As being an easily applicable test by blood sample and having high sensitivity and specificity, SEPT9 should take its place in routine screening protocols.