FDA panel backs DNA test for colon cancer

The AP reported that an FDA panel has voted to recommend an experimental “test that uses DNA to detect colon cancer and precancerous growths.” The article noted the panel voted 10-0 “that the benefits of Exact Sciences’ Cologuard test,” which analyzes stool specimens, “outweigh its risks.”

Reuters reported that Exact Sciences noted that using a set of DNA and hemoglobin markers, the test was able to find 92.3 percent of colorectal cancers in average risk patients.

The Milwaukee Journal Sentinel provided additional details of the test, noting that Cologuard can “detect early-stage cancer better than other noninvasive approaches,” citing a study unveiled by the New England Journal of Medicine. “In the study, which involved nearly 13,000” patients at several testing sites, Cologuard detected 42 percent “of advanced precancerous lesions,” in addition to the more than 92 percent of colorectal cancers, the paper noted.

Bloomberg News reports that the research indicated that the test, which uses “the DNA of specimens that patients collect at home detects more tumors than methods focusing on blood in the stool.”

Researchers found that the new test, known as Cologuard, “detected 92 percent of cancers and 42 percent of advanced precancerous growths, significantly more than an older test that looks only for blood in the stool.” However, “false positives occurred in more patients, about 13 percent, with Cologuard.”

On its website, NBC News reports that “the test isn’t very good at finding little growths that have not yet become cancerous,” which is “why colonoscopy remains the gold standard — doctors can find and remove those growths before they ever become dangerous.”

MedPage Today points out that the new “test evolved from recognition that colorectal cancer arises from an accumulation of genetic and epigenetic changes, providing the basis for a noninvasive stool test to identify tumor-specific changes.”

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