FDA Approves Blood Test for Colorectal Cancer Screening

"This decision will help make screening tests more broadly accessible and propel blood-based testing and CRC screening into a new era," according to Daniel Chung, MD.

The FDA has approved Shield^TM, a noninvasive, blood-based test designed to screen for colorectal cancer (CRC) in individuals 45 years and older who are at average risk of developing the disease, according to a press release from the developer, Guardant Health, Inc.¹

Shield is the first FDA-approved blood test intended for use as a primary screening option for CRC. Healthcare providers may screen for CRC via Shield in a similar fashion as all other noninvasive detection tools recommended in screening guidelines. According to the press release, a positive result with Shield may indicate the presence of CRC or advanced adenoma, and a patient should receive a referral for colonoscopy evaluation following this outcome.

“The persistent gap in [CRC] screening rates shows that the existing screening options do not appeal to millions of people,” Daniel Chung, MD, a gastroenterologist at Massachusetts General Hospital and a professor of medicine at Harvard Medical School, stated in the press release.¹ “The FDA's approval of the Shield blood test marks a tremendous leap forward, offering a compelling new solution to close this gap. This decision will help make screening tests more broadly accessible and propel blood-based testing and CRC screening into a new era. With increased screening rates and early cancer detection, many more lives can be saved.”

In May 2024, the Molecular and Clinical Genetics Panel of the FDA’s Medical Devices Advisory Committee issued a strong recommendation for approving Shield in the aforementioned population.² Members of the committee cast an 8-to-1 vote in support of Shield’s safety. Additionally, they voted in 6-to-3 in favor of the test’s efficacy and 7-to-2 in support of its benefits outweighing its risks.

Supporting data for the approval of Shield for CRC screening came from the ECLIPSE trial (NCT04136002), which investigators published in The New England Journal of Medicine.³

Findings showed that 83.1% of patients with CRC as detected via colonoscopy had a positive cell-free DNA (cfDNA) test while 16.9% had a negative result, representing a sensitivity of 83.1% (95% CI, 72.2%-90.3%) for CRC detection. Additionally, the test demonstrated a sensitivity of 13.2% (95% CI, 11.3%-15.3%) for advanced precancerous lesions.

The specificity rate for nonadvanced adenomas, nonneoplastic findings, and negative colonoscopy was 89.6% (95% CI, 88.8%-90.3%) with the blood-based test. Additionally, the specificity was 89.9% (95% CI, 89.0%-90.7%) for nonneoplastic findings plus negative colonoscopy.

“Evaluation of participant adherence to this cfDNA blood-based test in various clinical settings is warranted and is an area of active investigation, especially given that participant adherence is affected by many factors beyond the test availability,” Chung and coauthors wrote in the study.³ “In addition, future work that involves health economic and outcomes modeling could inform the effect of this blood-based test on [CRC]–related outcomes, specifically the effect of a test with high adherence and lower sensitivity for advanced precancerous lesions than stool-based testing, and could assess whether the 3-year interval of the blood-based test, proposed by the manufacturer for screening, yields beneficial clinical outcomes.”

The ECLIPSE trial included a clinical validation cohort of 10,258 individuals, with 7861 meeting all inclusion criteria and completing colonoscopy and blood-based screening. The trial’s coprimary end points were sensitivity for CRC and specificity for advanced neoplasia in individuals who were at average risk of developing disease. The secondary end point was sensitivity for detecting advanced precancerous lesions such as advanced adenoma, adenoma of any size with villous features, and high-grade dysplasia.

References

1. Guardant Health’s Shield™ blood test approved by FDA as a primary screening option, clearing path for Medicare reimbursement and a new era of colorectal cancer screening. News release. Guardant Health, Inc. July 29, 2024. Accessed July 29, 2024. https://tinyurl.com/mr2c3uhm
2. FDA Advisory Committee Panel strongly recommends approval of Shield™ blood test for colorectal cancer screening as a primary non-invasive screening option. News release. Guardant Health, Inc. May 23, 2024. Accessed July 29, 2024. https://tinyurl.com/zvd9yava
3. Chung DC, Gray DM, Singh H, et al. A cell-free DNA blood-based test for colorectal cancer screening. N Engl J Med. 2024;390(11):973-983. doi:10.1056/NEJMoa2304714