On Monday, August 11, the U.S. Food and Drug Administration announced its approval of the first stool-based colorectal screening test co-developed by molecular-diagnostics company Exact Sciences and Mayo Clinic. Exact Sciences will be the sole provider of this new test. While the test is based on Mayo Clinic research, the test will not be available through Mayo Medical Laboratories.
According to an Exact Sciences’ press release, “Cologuard is the first noninvasive screening test for colorectal cancer that analyzes both stool DNA and blood biomarkers and has been proven to find 92 percent of cancers and 69 percent of the most advanced precancerous polyps in average-risk patients. Cologuard, which is available through health care providers, offers people 50 or older at average risk for colorectal cancer an easy-to-use screening test they can do in the privacy of their own homes.”
To learn more about the new Cologuard, visit CologuardTest.com.
Results of the Clinical Trial at Mayo Clinic
Results of a clinical trial of Cologuard show unprecedented rates of precancer and cancer detection by a noninvasive test. The results were published in the March 20, 2014, issue of the New England Journal of Medicine. Cologuard was co-developed by Mayo Clinic and Exact Sciences. Cologuard is a noninvasive sDNA (stool DNA) test for the early detection of colorectal precancer and cancer. The Cologuard test is based on a stool sample that is analyzed for DNA signatures of precancer or cancer. The samples are easily collected; mailed from the patient’s home; and require no bowel preparation, medication restriction, or diet change. The clinical trial, called the DeeP-C study, included 10,023 subjects and was designed to determine how well Cologuard detects precancer and cancer. The study also compared Cologuard to the fecal immunochemical test for occult blood (FIT). The study was conducted at 90 medical centers throughout the United States and Canada.
“Cologuard detection rates of early stage cancer and high-risk precancerous polyps validated in this large study were outstanding and have not been achieved by other noninvasive approaches,” says the study’s author David Ahlquist M.D., a Mayo Clinic gastroenterologist and co-inventor of the Cologuard test. “It is our hope that this accurate and user-friendly test will expand screening effectiveness and help curb colorectal cancer rates in much the same way as regular Pap smear screening has done for cervical cancer.”
In the study, all patients received Cologuard, FIT, and a colonoscopy. Colonoscopy was the reference method.
Major findings reported in the study include:
- Sensitivity of Cologuard for cancer was 92 percent overall, and 94 percent for the earliest and most curable cancer stages (stages I and II).
- Sensitivity was 69 percent for precancerous polyps at greatest risk to progress to cancer (i.e., those containing high-grade dysplasia).
- Cologuard detected significantly more cancers and significantly more precancerous polyps than did FIT.