AT A GLANCE

A new study published in JAMA reports that a blood-based test demonstrated acceptable accuracy for colorectal cancer detection, although its detection of advanced precancerous lesions remains inadequate.¹

“Colorectal cancer screening is widely recommended but underused. Blood-based screening offers the potential for higher adherence compared with endoscopy or stool-based testing but must first be clinically validated in a screening population,” explain study authors Shaukat.

In response, the authors evaluated the clinical performance of an investigational blood-based circulating tumor DNA test for colorectal cancer detection in an average-risk population, using colonoscopy with histopathology as the reference method, as part of a prospective, multicenter, cross-sectional observational study at 201 centers across the United States and the United Arab Emirates. Patients eligible for inclusion were those aged 45–85 years at average risk of colorectal cancer and willing to undergo a standard-of-care screening colonoscopy. Participants were required to complete a screening colonoscopy after blood collection, and participants, staff, and pathologists were blinded to blood test results, while laboratory testing was performed blinded to colonoscopy findings. The primary endpoints of interest included sensitivity for colorectal cancer, specificity for advanced colorectal neoplasia (colorectal cancer or advanced precancerous lesions), negative predictive value for advanced colorectal neoplasia, and positive predictive value for advanced colorectal neoplasia, while the secondary endpoint of interest was sensitivity for advanced precancerous lesions.

According to the authors, the sensitivity for colorectal cancer was 79.2%, and the specificity for advanced colorectal neoplasia was 91.5%, while the negative predictive value for advanced colorectal neoplasia was 90.8% and the positive predictive value for advanced colorectal neoplasia was 15.5%. All primary endpoints met prespecified acceptance criteria. Meanwhile, the sensitivity for advanced precancerous lesions was 12.5%, which did not meet the prespecified acceptance criterion.

“In an average-risk colorectal cancer screening population, a blood-based test demonstrated acceptable accuracy for colorectal cancer detection, but detection of advanced precancerous lesions remains a challenge, and ongoing efforts are needed to improve test sensitivity,” conclude the authors.

Reference

1.     Shaukat A, Burke CA, Chan AT, et al. Clinical validation of a circulating tumor DNA-based blood test to screen for colorectal cancer (online ahead of print June 2, 2025). JAMA.