Mayo Clinic research results presented in NEJM could change colorectal screening practice
ROCHESTER, Minn. — March 19, 2014 — Results of a clinical trial of Cologuard show unprecedented rates of precancer and cancer detection by a noninvasive test. The detection rates are similar to those reported for colonoscopy. The results were published in the March 20 issue of the New England Journal of Medicine (NEJM). Cologuard was co-developed by Mayo Clinic and Exact Sciences. Cologuard, is a noninvasive sDNA 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 home, requires no bowel preparation, medication restriction or diet change. The clinical trial, called the DeeP-C study, included 10,000 patients 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 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.