New DNA stool test for colon cancer shows promise in study

March 25, 2014

According to research published in the New England Journal of Medicine, the new Colorguard at-home stool test, manufactured by Wisconsin-based Exact Sciences Corp., screens for colorectal cancer with more than 90% accuracy, A multi-target test, it checks for blood as well as abnormal DNA coming from the tumor. Colorguard is not yet approved for use by the U.S. Food and Drug Administration.

Study authors compare the effectiveness of the new DNA test to colonoscopy screenings and to a commercially available fecal immunochemical test (FIT).To assess the potential of the DNA method, nearly 10,000 men and women aged 50 and older were screened for colon cancer and precancerous polyps at one of 90 sites. All were considered at average risk for colon cancer.

The researchers report that colonoscopy screenings identified colon cancer in 65 participants, while another 757 were found to have advanced precancerous lesions. The new test accurately detected 60 of those 65 cancers, while the FIT test detected 48 malignancies.

The DNA test was less accurate with respect to precancerous lesions, spotting about 42% of cases. That still exceeded the FIT, which detected roughly 24% of precancerous lesions. Cologuard's sensitivity was 69% for precancerous polyps most likely to progress to cancer, versus 46% for the FIT test.The DNA test was more likely to falsely suggest the presence of cancer than either FIT testing or colonoscopy. Read the study abstract.

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