Two different stool tests for colorectal cancer screening, Cologuard and ColoSense, proved superior to the widely used fecal immunochemical test (FIT), according to study results presented at the American College of Gastroenterology Annual Scientific Meeting.

The U.S. Preventive Services Task Force and the American Cancer Society recommend that people at average risk should receive colorectal cancer screening starting at age 45. The organizations recommend both colonoscopy and noninvasive approaches. While colonoscopy is considered the gold standard for detecting and clearing colorectal lesions, stool tests are more convenient and do not require extensive preparation, meaning more people may be willing to use them.

Next-Generation Cologuard

The original Cologuard test, from Exact Sciences, is a highly sensitive colorectal cancer screening tool. The Food and Drug Administration (FDA) approved the test in 2014. The next-generation Cologuard test is even more sensitive.

Thomas Imperiale, MD, of Indiana University School of Medicine, presented findings from the BLUE-C colorectal screening trial (NCT04144738), which evaluated the next-generation Cologuard multitarget stool DNA test. Results were also reported in The New England Journal of Medicine.

The study population included more than 20,000 asymptomatic participants ages 40 and older who were undergoing screening colonoscopy. Of these, 98 had colorectal cancer, mostly Stage I to III. In addition, 2,144 had advanced precancerous lesions, 6,973 had nonadvanced malignant lesions and 10,961 had benign lesions or a negative colonoscopy.

The researchers evaluated the test’s sensitivity, meaning it can detect cancer or precancerous lesions when present, and its specificity, or ability to rule out cancer when it is absent

The next-generation Cologuard test had 94% sensitivity for detecting colorectal cancer and 91% specificity for findings advanced neoplasia. Compared to the FIT test, Cologuard was more likely to diagnose cancer (94% versus 67%), advanced precancerous lesions (43% versus 23%) and high-grade dysplasia (75% versus 47%). Cologuard’s specificity was 91% for ruling out advanced neoplasia and 93% for benign lesions or no cancer, compared with 95% and 96%, respectively, for FIT.

As compared with FIT, the next-generation Cologuard test had superior sensitivity for colorectal cancer and for advanced precancerous lesions but had lower specificity for advanced neoplasia, the study authors concluded.

ColoSense

While Cologuard is a multitarget DNA test, ColoSense, from Geneoscopy, is a multitarget RNA stool test. The FDA approved ColoSense this May.

Erica Barnell, MD, PhD, of Washington University School of Medicine and Geneoscopy’s chief science and medical officer, presented findings from the CRC-PREVENT trial (NCT04739722), which evaluated the effectiveness of ColoSense for older adults. Results were also reported in JAMA.

The study included nearly 9,000 participants ages 45 and older recruited through social media. Stool samples were collected and tested with ColoSense prior to participants undergoing a colonoscopy at a local center. Of these, 36 (0.40%) were found to have colorectal cancer and 606 (6.8%) had advanced precancerous lesions.

The sensitivity of ColoSense was 94% for detecting colorectal cancer and 46% for detecting advanced adenomas. The corresponding sensitivity for FIT was 78% and 29%, respectively. ColoSense had 88% specificity for ruling out cancer in people found to have no lesions on a colonoscopy.

“In individuals 45 years and older, the mt-sRNA [ColoSense] test showed high sensitivity for colorectal neoplasia (colorectal cancer and advanced adenoma) with significant improvement in sensitivity relative to the FIT,” the researchers concluded. “Specificity for no lesions on colonoscopy was comparable to existing molecular diagnostic tests.”

Click here for more news about colon cancer.