Shield CRC blood test demonstrates adherence of 95% in new study of 20,000 patients – Guardant Health

Guardant Health Inc announced new real-world data published in Current Medical Research and Opinion finding that the Shield blood-based screening test demonstrates patient adherence of 95% in screening for colorectal cancer (CRC). Shield is the first and only blood test to receive FDA approval as a primary screening option for colorectal cancer in average-risk adults aged 45 and older.

In the analysis looking at the initial implementation of a blood-based CRC screening test, Shield yielded an adherence rate of 95%. In the first 20,000 patients with a Shield clinical order placed between May 2022 and June 2024 patient adherence far surpassed reported adherence rates for colonoscopy or stool-based tests (25-71%). Median test turnaround time was 15 days from blood sample receipt to a results report.

This  study is the latest in a growing body of evidence showing that Shield increases patient adherence. An additional study looked at two primary care clinics in Appalachia which ranks low in screening for colorectal cancer with correspondingly some of the highest incident and mortality rates in the U.S. In this study , Shield had a clear positive impact increasing overall screening rates for CRC, with positive patient and provider satisfaction, and was the clear preference for screening.

Key findings from the additional study in Appalachia included:

• i) An increase in overall rates of screening from 45% to 90% when Shield was added as an option.
• ii) Shield had an adherence rate of 98.5%.

“We continue to see compounding evidence that when patients are prescribed Shield, they are highly likely to complete the test in real-world clinical practice,” said Dr. Craig Eagle, Guardant Health Chief Medical Officer. “Through a simple blood draw, Shield is proving to be an accessible and pleasant option for physicians and patients.”

Colorectal cancer is the second leading cause of cancer-related deaths in the U.S. The disease has a 91 percent five-year survival rate if caught in early stages. Yet, one out of three eligible adults in the U.S. — over 50 million people — do not complete the recommended screening, in part because they find the available options, colonoscopy and stool tests, unpleasant or inconvenient. With Shield, individuals can be screened with a simple blood draw, helping to detect cancer early, when it is more treatable. Shield is commercially available across the U.S.

See  citations-  Graham-Adderton  C., Guerra, CE. et al.  Implementation of blood-based colorectal cancer screening: real-world adherence and outcomes. Curr Med Res Opini 2025 , 1–8. https://doi.org/ 10.1080/03007995.2025.2582257

Haynes WB Jr, Talari MP et al. Blood-Based Colorectal Cancer Screening: Implementation Into 2 Appalachian Primary Care Clinics.  Am J Prev Med  2025, 69:107636  doi: 10.1016/j.amepre.2025.04.006.