FDA Advisory Committee Recommends Approval of Shield Blood Test for CRC Detection in Average-Risk Adults


The FDA’s Medical Devices Advisory Committee recommends the approval of the Shield blood test for CRC screening in adults at average risk for CRC.



The FDA’s Medical Devices Advisory Committee has strongly recommended the approval of Guardant Health’s Shield blood test for colorectal cancer (CRC) screening in adults 45 years of age and older who are at average risk of developing this disease.1 The recommendation represents the committee’s consensus on the safety and efficacy of Shield in its proposed intended use, as well as the committee’s conclusion that the test’s benefits as a primary noninvasive screening option outweigh any potential risks, according to a press release.

The FDA is expected to decide on the approval of Shield later in 2024.

“The advisory committee’s strong support for the approval of Shield reinforces the crucial role that a blood test option can have in improving CRC screening rates for those at average risk,” AmirAli Talasaz, co-chief executive officer of Guardant Health, stated in the press release. “Despite the importance of detecting CRC early, there are notable barriers that can deter average-risk Americans from completing existing screening methods. Shield effectively detects cancer at an early stage when it is most treatable. Providing people with this blood test alongside other noninvasive stool tests can increase the rate of colorectal screening and potentially reduce preventable CRC deaths.”

The Committee’s recommendation is based on Guardant’s premarket approval application for Shield, which include findings from the observational ECLIPSE study (NCT04136002) investigating the performance of Shield for detecting CRC in adults at average risk of developing CRC. Results from the study, which were published in The New England Journal of Medicine, demonstrated that Shield had an 83.1% CRC detection sensitivity rate, meaning that 83.1% of patients with CRC detected by colonoscopy had a positive Shield result (95% CI, 72.2%-90.3%).2 Additionally, Shield demonstrated an 89.6% advanced neoplasia specificity rate, meaning that 89.6% of patients without advanced colorectal neoplasia detected by colonoscopy had a negative Shield result (95% CI, 88.8%-90.3%). The performance of Shield is within the range of the performance of existing stool-based tests that are used as primary CRC screening options, which have overall sensitivity rates ranging from 67% to 92%.1

Shield is a qualitative in vitro diagnostic test designed to detect CRC derived from cell-free DNA alterations in blood collected with the Guardant Blood Collection Kit. Patients with an “Abnormal Signal Detected” may have CRC or advanced adenomas and are recommended to receive colonoscopy evaluation. For patients at high risk of developing CRC, Shield is not a replacement for diagnostic or surveillance colonoscopy.

The Committee panel members voted on 3 questions about the use of Shield in patients meeting the criteria for Shield use that are outlined in the test’s proposed indication. An 8-to-1 vote demonstrated the panel’s reasonable assurance that Shield is safe; a 6-to-3 vote demonstrated the panel’s reasonable assurance that Shield is effective; and a 7-to-2 vote demonstrated the panel’s belief that the benefits of Shield outweigh its risks.

“Sadly, 76% of deaths caused by CRC occur in individuals who are not up to date with their screening,” Daniel Chung, MD, a gastroenterologist at Massachusetts General Hospital and a professor of medicine at Harvard Medical School, both in Boston, added in the press release. “Clinical evidence and CRC screening guidelines acknowledge the value of offering choice to individuals at average risk for CRC and highlight the role of patient preference in test selection and CRC screening completion.”


  1. 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. May 23, 2024. Accessed May 24, 2024.
  2. Chung DC, Gray DM 2nd, 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

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