Guardant Health, a precision oncology company, has submitted to the U.S. Food and Drug Administration (FDA) the final module of its premarket approval (PMA) application for Shield, Guardant Health’s blood test to screen for colorectal cancer (CRC).

The submission is comprised of data from the company’s positive ECLIPSE study, an over 20,000 patient registrational study evaluating the performance of its blood test for detecting colorectal cancer in average-risk adults. Preliminary results from the study showed that the Shield test achieved 83% sensitivity for the detection of colorectal cancer with specificity of 90%.

“Completing our FDA PMA application for Shield is a significant step forward toward our mission of saving millions of life-years through accessible blood-based cancer screening. We are looking forward to partnering with the agency on bringing this life-saving test to the market,” says AmirAli Talasaz, co-CEO of Guardant Health. “Colorectal cancer is the second leading cause of cancer related death, yet one in three eligible adults are not up to date with screening.1 Patient access to blood-based screening can help overcome barriers to traditional screening modalities, especially in underserved populations.”

The success of a CRC screening program depends on having tests with acceptable performance, but also on the willingness of the target population to complete the screening test.2 

Since the launch of the lab-developed version of the Shield test in May 2022, it has shown approximately 90% adherence in a real-world clinical setting, demonstrating the value of blood-based screening to increase adherence to recommended screening protocols.3 The effective sensitivity of the test, which measures the true impact of a screening test by evaluating adherence and test performance, shows that Shield may be able to detect more CRCs than traditional modalities.3,4,5,6


  1. American Society of Clinical Oncology. Colorectal cancer: statistics. website. Updated February 2022. Accessed February 17, 2023.
  2. Adler A, Geiger S, Keil A, et al. Improving compliance to colorectal cancer screening using blood and stool based tests in patients refusing screening colonoscopy in Germany. BMC Gastroenterol. 2014;14:183. doi:10.1186/1471-230X-14-183
  3. Shield LDT internal data on file. Guardant Health, Inc.
  4. Bretthauer M, Løberg M, Wieszczy P, et al.; NordICC Study Group. Effect of colonoscopy screening on risks of colorectal cancer and related death. N Engl J Med. 2022;387:1547-1556.
  5. Knudsen AB, Rutter CM, Peterse EFP, et al. Colorectal cancer screening: An updated decision analysis for the U.S. Preventive Services Task Force. Rockville (MD): Agency for Healthcare Research and Quality; 2021a. Report No.: 202s.
  6. lmperiale TF, Ransohoff DF, Itzkowitz SH, et al. Multitarget stool DNA testing for colorectal-cancer screening. NEJM. 2014.