FDA Approves Cologuard for Colorectal Cancer Screening

Roxanne Nelson


August 11, 2014

(Corrected Aug. 12, 2014) The US Food and Drug Administration (FDA) today approved Cologuard (Exact Sciences Corporation), a stool-based colorectal cancer (CRC) in vitro diagnostic device.

Cologuard analyzes stool specimens to detect hemoglobin, multiple DNA methylation and mutational markers, and the total amount of human DNA contained in cells that are shed by CRC or advanced adenomas into the colon.

Cologuard is intended for the qualitative detection of colorectal neoplasia–associated DNA markers and for the presence of occult hemoglobin in human stool. A positive result may indicate the presence of CRC or advanced adenoma and should be followed by diagnostic colonoscopy. Cologuard is indicated to screen adults of either sex, 50 years or older, who are at typical average-risk for CRC. Cologuard is not a replacement for diagnostic colonoscopy or surveillance colonoscopy in high-risk individuals.

As previously reported by Medscape Medical News, an FDA advisory panel recommended premarket approval in March.

"This approval offers patients and physicians another option to screen for colorectal cancer," said Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health at the FDA's Center for Devices and Radiological Health (CDRH), in a statement. "Fecal blood testing is a well-established screening tool and the clinical data showed that the test detected more cancers than a commonly used fecal occult test."

Stool or fecal DNA testing is not currently recommended as a method to screen for colorectal cancer by the United States Preventive Services Task Force (USPSTF). Among other guidelines, the USPSTF recommends that adults aged 50 to 75 years at average risk for colon cancer be screened using fecal occult blood testing, sigmoidoscopy, or colonoscopy.

Better Than FIT

The safety and effectiveness of Cologuard was established in a large clinical trial that screened 10,023 individuals and compared the performance of Cologuard to the fecal immunochemical test (FIT), a commonly used noninvasive screening test that detects blood in the stool. Cologuard proved superior to FIT in accurately detecting cancers and advanced adenomas.

Cologuard detected 92% of colorectal cancers and 42% of advanced adenomas, as compared with FIT screening, which detected 74% of cancers and 24% of advanced adenomas.

However, Cologuard was less accurate than FIT at correctly identifying patients who were negative for colorectal cancer or advanced adenomas, giving a negative screening result for 87% of the cohort vs 95% for FIT.

Joint Approval With CMS

The Centers for Medicare & Medicaid Services (CMS) today also issued a proposed national coverage determination for Cologuard, making it the first product to be reviewed through a joint FDA-CMS pilot program. Known as parallel review, the 2 agencies concurrently review medical devices, which in turn shortens the waiting time between FDA and CMS coverage.

"Parallel review allows the last part of the FDA process to run at the same time as the CMS process, cutting as many as six months from the time from study initiation to coverage," said Nancy Stade, CDRH's deputy director for policy, in a release. "The pilot program is ongoing, but we will apply what we have learned to improve the efficiency of the medical device approval pathway for devices that address an important public health need."

Proposed CMS coverage for the Cologuard test would be once every 3 years for Medicare beneficiaries aged 50 to 85 years who are asymptomatic (no signs or symptoms of colorectal disease including but not limited to lower gastrointestinal pain, blood in stool, positive guaiac fecal occult blood test or fecal immunochemical test) and at average risk of developing colorectal cancer (no personal history of adenomatous polyps, colorectal cancer, or inflammatory bowel disease, including Crohn's disease and ulcerative colitis; no family history of colorectal cancers or an adenomatous polyp, familial adenomatous polyposis, or hereditary nonpolyposis colorectal cancer).

Correction: This article has been corrected to remove the word "adjunctive" regarding the intention of the screening test. The FDA did not specifically approve Cologuard as an adjunctive test.


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