Exact Sciences Corp. has announced that a new peer-reviewed study of Cologuard®, a multi-target stool DNA test (MT-sDNA), confirms its performance across all stages of colorectal cancer and showcases how the at-home test could improve access to screening. In the study of 661 average risk Alaska Native people, Cologuard detected 100% (10/10) of colorectal cancers and 52% (24/46) of significant premalignant lesions (adenomas >1 cm) in people between the ages of 40-85. The detection rate of Cologuard increased to 80% for the largest pre-cancers (>3 cm), which are most likely to progress to cancer. The study, "Stool DNA Testing for Screening Detection of Colorectal Neoplasia in Alaska Native People" is published in Mayo Clinic Proceedings.
The Alaska Native people have among the world's highest rates of colorectal cancer, more than twice the rate of U.S. Caucasians. Colorectal cancer is also the most commonly diagnosed cancer among this population. Conventional invasive screening approaches, such as colonoscopy, present access challenges for people in remote Alaskan villages. The colorectal cancer screening rate for some Alaska Native people is as low as 23%, far below the national screening rate of 58%.
"This research is further evidence that Cologuard is highly sensitive in detecting both early stage colorectal cancer and the most advanced precancerous polyps that are most likely to develop into cancer," said David Ahlquist, M.D., a Mayo Clinic gastroenterologist, study investigator and co-inventor of the test. "A sensitive screening test like Cologuard that is delivered to a patient's home provides an opportunity to reverse that trend not only in Alaska but also in other rural and remote areas where patients have limited access to screening."
As part of the study, which mirrored a previously published (New Engl J Med April 2014) 10,000 patient prospective study of Cologuard, participants underwent both Cologuard and fecal immunochemical testing (FIT) prior to a pre-scheduled screening or surveillance colonoscopy. The Alaska Native study results improved upon the previously published results, showing a higher rate of sensitivity for colorectal cancer and pre-cancer and an increased specificity. FIT detected 80% (8/10) of colorectal cancers and only 30% of significant premalignant lesions (adenomas >1 cm). Cologuard achieved a specificity of 93% and FIT achieved a specificity of 96%.
"This study of Alaska Native people confirms the power of Cologuard and reaffirms its importance in our effort to increase America's stagnating colon cancer screening rates," said Kevin Conroy, chairman and CEO of Exact Sciences. "Not only did Cologuard's sensitivity remain high across all cancer stages and pre-cancers, but its false positive rate decreased. Cologuard's performance highlights its role as a screening option."