Blood-Based Screening Demonstrates Promising Accuracy for Detecting Colorectal Cancer

A recent study published in the Journal of the American Medical Association reveals that blood-based tests can offer a reliable method for detecting colorectal cancer, though challenges remain in identifying advanced precancerous lesions. The research involved a large, multicenter, prospective study with over 27,000 asymptomatic adults aged 45 to 85, all at average risk for colorectal cancer. Participants underwent blood testing for circulating tumor DNA, followed by standard colonoscopy procedures.

The findings showed a sensitivity of 79.2% for detecting colorectal cancer, meaning the test accurately identified the majority of cancer cases. The specificity was high at 91.5%, indicating that false positives were relatively low. The negative predictive value was impressive at 90.8%, suggesting that a negative test result reliably indicated the absence of cancer. The positive predictive value for advanced colorectal neoplasia was 15.5%, with a sensitivity of 12.5% for advanced precancerous lesions—this latter figure did not meet the primary acceptance criteria.

While the blood test proved promising for identifying existing cancers, it showed limited effectiveness in detecting early precancerous changes, which are crucial for preventive interventions. The authors emphasize that ongoing improvements are needed to enhance the sensitivity of such blood-based screening methods before they can be widely adopted. Funding for this study was provided by Freenome Holdings Inc., a biopharmaceutical company.

This research suggests that blood-based screening could potentially complement existing colorectal cancer screening strategies, providing a less invasive option for early detection. However, further development is necessary to improve its ability to detect early precancerous conditions effectively.

For more information, the study is available through the Journal of the American Medical Association (JAMA).