Review the ECLIPSE study published in New England Journal of Medicine.  See the data

Frequently Asked Questions (FAQs)

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A blood-based test, like Shield™, is optimized to accurately assess for DNA shed by tumors called circulating tumor DNA (ctDNA) to detect colorectal cancer through a simple blood draw. We apply a multimodal approach that analyzes genomic alterations and epigenomic modifications. Shield integrates these signals to produce an actionable result of either "abnormal signal detected" or "normal signal detected."1-5

Simply because patients who are not up to date with screening are at greater risk of CRC mortality. In fact, over 75% of people who died from CRC were not up to date with screening.6 CRC remains the second-leading cause of cancer-related deaths in the US.7 Sadly, over half of patients are diagnosed after their disease has spread and when survival rates are drastically lower.7-9 A blood-based approach can improve these statistics and increase patient compliance by overcoming barriers associated with available screening options—colonoscopy and stool-based testing.5

Get started with Shield by filling out the form at

Please call 1.855.722.7335 or email to request more information.

We analyze Shield blood samples as soon as possible and deliver test results in ~2 weeks of receiving the samples in our lab.

Please email with your request and best contact information, and a Guardant Market Access team member will contact you.

The ECLIPSE clinical study, published in the New England Journal of Medicine, was a large-scale colorectal cancer screening study that evaluated the performance of Shield, Guardant Health’s blood-based test for the detection of asymptomatic and early-stage CRC.5 A prospective, multi-site registrational study, ECLIPSE validated Shield in over 10,000 average-risk patients between the ages of 45 and 84 at over 200 sites across the US. The study demographics were generally reflective of the US population, with above-average enrollment among black Americans for a clinical study.5,10

The study demonstrated 83% sensitivity, 90% specificity, and 99.9% negative predictive value for Shield, an easy-to-complete blood test.5

The data from this trial were used to support a submission to the FDA and enable Centers for Medicare and Medicaid Services (CMS) coverage.10

We’d be happy to keep you updated on the latest developments. Please sign up to stay up to date.

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Please click here to find more information about Shield data, including the ECLIPSE trial publication from the March 14, 2024 issue of New England Journal of Medicine.

No special preparations are needed for patients since a simple blood draw is all that is required. This means that patients do not need to make dietary changes, undergo sedation, or take extra time away from work or family.11

  • The current USPSTF recommends screening for all eligible adults 45 to 75 years old for CRC12
  • The USPSTF does not identify any head-to-head studies demonstrating superiority of screening options. The goal is to maximize the total number of people who will be screened12
  • The USPSTF recommendations are classified into different grades below12
Adults aged
50 to 75 years
The USPSTF recommends screening for colorectal cancer in adults aged 50 to 75 years.
Adults aged
45 to 49 years
The USPSTF recommends screening for colorectal cancer in adults aged 45 to 49 years.
Adults aged
76 to 85 years
The USPSTF recommends that clinicians selectively offer screening for colorectal cancer in adults aged 76 to 85 years. Evidence indicates that the net benefit of screening all persons in this age group is small. In determining whether this service is appropriate for individual cases, patients and clinicians should consider the patient’s overall health, prior screening history, and preferences.

Guardant Access is committed to making Shield accessible to all eligible patients.

For US patients

  • Designed to limit surprise bills by notifying patients with an estimated out-of-pocket cost >$50 USD
  • Eligible patients can receive financial assistance

For US practices

  • We provide Shield—related eligibility confirmation, manage claims and appeals, and field all your patients´ billing questions

Financial assistance eligibility determination is available for all eligible patients regardless of insurance type.

Phone: 1.855.722.7335, ext. 1, then press 2


Please visit our contact us page to find out the best way to ask us additional questions.

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*The ECLIPSE study (NCT04136002) is comparing the sensitivity and specificity of cell-free DNA (cfDNA)-only Shield with findings from subsequent colonoscopy in over 10,000 average-risk patients.10,11
Shield™ is a qualitative laboratory developed test intended to detect colorectal cancer by identifying genomic and epigenomic alterations in cell-free DNA in plasma from blood collected in Guardant blood collection tubes.
  • The assay is intended to be complementary to and not a replacement for current recommended colorectal cancer screening methods
  • Patients with an "abnormal signal detected" Shield test result should be referred for colonoscopic evaluation
  • A "normal signal detected" Shield test result does not preclude the presence of colorectal cancer, and patients should continue participating in guideline-recommended screening programs
  • Shield was developed, and its performance characteristics determined, by the Guardant Health Clinical Laboratory in Redwood City, CA, USA, which is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) as qualified to perform high complexity clinical testing. This test has not been cleared or approved by the US FDA
References 1. Lee J, Kim HC, Kim ST, et al. Multimodal circulating tumor DNA (ctDNA) colorectal neoplasia detection assay for asymptomatic and early-stage colorectal cancer (CRC). J Clin Oncol. 2021;39(suppl 15):3536. 2. Chung D, Gray DM, Greenson J, et al. 913e Clinical validation of a cell-free DNA blood-based test for colorectal cancer screening in an average risk population. Gastroenterology. 2023;164(6):S. doi:10.1016/S0016-5085(23)04760-1 3. Westesson O, Axelrod H, Dean J, et al. Integrated genomic and epigenomic cell-free DNA (cfDNA) analysis for the detection of early-stage colorectal cancer. Cancer Res. 2020;80(suppl 16):2316. doi:10.1158/1538-7445.AM2020-2316 4. 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 5. Chung DC, Gray DM II, 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 6. Doubeni CA, Fedewa SA, Levin TR, et al. Modifiable failures in the colorectal cancer screening process and their association with risk of death. Gastroenterology. 2019;156(1):63-74. doi:10.1053/j.gastro.2018.09.040 7. American Society of Clinical Oncology. Colorectal cancer: statistics. website. Updated January 2021. Accessed May 10, 2021. 8. American Cancer Society. Colorectal cancer facts & figures 2017-2019. Accessed April 20, 2021. 9. National Cancer Institute. Colon and rectum stage distribution of SEER incidence cases, 2009-2018. Accessed November 10, 2021. 10. Guardant Health ECLIPSE Study data demonstrating efficacy of Shield blood-based test for colorectal cancer screening to be published in the New England Journal of Medicine. March 13, 2024. Accessed March 15, 2024. 11. Rich T, Raymond V, Lang K. Where are we today? Efforts to understand strategies and barriers to physician issuance of a recommendation for colorectal cancer screening: a systematic review. Gastroenterology. 2020;158(6 suppl 1):S-918. doi:10.1016/S0016-5085(20)32981-4 12. Davidson KW, Barry MJ, Mangione CM, et al; US Preventive Services Task Force. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(19):1965-1977. doi:10.1001/jama.2021.6238