US FDA Approves Noninvasive DNA Colorectal Cancer Screening Test
05 Sep 2014
The first stool-based colorectal screening test that detects the presence of red blood cells and DNA mutations has been officially approved.
The test uses a stool sample and indicates the presence of certain kinds of abnormal growths that may be cancers, such as colon cancer or precursors to cancer, as colorectal cancers start as abnormal raised or flat tissue growths on the wall of the large intestine or rectum (polyps).
The US Food and Drug Administration (FDA; Silver Spring, MD, USA) approved the Cologuard test manufactured by Exact Sciences (Madison, WI, USA). The test detects certain mutations associated with colorectal cancer in the DNA of cells shed by advanced adenomas as stool moves through the large intestine and rectum. The test also detects hemoglobin, a protein molecule that is a component of blood. Patients with positive test results are advised to undergo a diagnostic colonoscopy.
The safety and effectiveness of Cologuard was established in a clinical trial that screened 10,023 subjects. The trial compared the performance of Cologuard to the fecal immunochemical test (FIT), a commonly used noninvasive screening test that detects blood in the stool. Cologuard accurately detected cancers and advanced adenomas more often than the FIT test. Cologuard detected 92% of colorectal cancers and 42% of advanced adenomas in the study population, while the FIT screening test detected 74% of cancers and 24% of advanced adenomas. Cologuard was less accurate than FIT at correctly identifying subjects negative for colorectal cancer or advanced adenomas. Cologuard correctly gave a negative screening result for 87% of the study subjects, while FIT provided accurate negative screening results for 95% of the study population.
Patrick Conway, MD, MSc, a chief medical officer at the Centers for Medicare & Medicaid Services (Baltimore, MD, USA) said, “This is the first time in history that FDA has approved a technology and CMS has proposed national coverage on the same day. This parallel review represents unprecedented collaboration between the two agencies and industry and most importantly will provide timely access for Medicare beneficiaries to an innovative screening test to help in the early detection of colorectal cancer.”