Newly Launched Blood Test Detects Early Signs of Colorectal Cancer

By LabMedica International staff writers
Posted on 04 May 2022

Image: Shield Test Kit (Photo courtesy of Guardant Health)

Colorectal cancer (CRC) is curable if caught early but still remains among the leading cause of cancer-related deaths, with cancer underscreening contributing significantly to the high cancer mortality rate in underserved populations. Barriers associated with currently available methods, such as a colonoscopy or a stool-based test, can make the process unpleasant, time-consuming and difficult to complete. Now, a newly-launched blood-based test for the detection of early-stage CRC intended for adults age 45 and older who are not up to date with recommended screening guidelines, show no symptoms, and are at average risk for CRC, only requires patients to complete a simple blood draw.

Guardant Health, Inc. (Redwood City, CA, USA) has launched the Shield test with a simple blood draw that overcomes barriers to testing because it requires no special preparation, no sedation, no dietary changes, no extra time away from family or work, and it can be completed as part of any patient office visits. The Shield test detects early signs of CRC signals in the bloodstream. The assay was developed using multiple cohorts comprising 2,089 subjects with CRC, 357 with advanced adenoma and 3,757 normal subjects. The samples were collected within both prospective screening collections designed to capture the intended use population and retrospective case-control cohorts designed to enrich for subjects with CRC.

The clinical performance of the Shield assay was validated using a set of 309 patient samples, including 92 with CRC, 51 with advanced adenomas and 166 normal cases. The Shield assay demonstrated 91% sensitivity (detection rate) for CRC, including 90% for Stage I, 97% for Stage II, and 86% for Stage III CRC. The assay also demonstrated 20% sensitivity for advanced adenomas (95% CI; 11% - 32%) and 92% specificity (true negative rate) in normal cases.

“The availability of the Shield test represents a major milestone in our commitment to transform cancer screening. We have developed highly sensitive technology to detect early-stage cancers with a simple blood draw,” said AmirAli Talasaz, Guardant Health co-CEO. “Colorectal cancer screening is the start of this journey. We will soon expand into multi-cancer screening, including lung, pancreas and others, where we believe cancer screening can save lives.”

“The value of colorectal cancer screening is well-established for individuals at average risk, age 45 and older,” added J. Leonard Lichtenfeld, MD, MACP, Chief Medical Officer, Jasper Health. “But the benefits of screening have been limited due to the suboptimal completion rates of stool tests and colonoscopy. A high-sensitivity test that can be completed with a convenient blood draw during any healthcare provider visit can help patients overcome the barriers to adherence and help healthcare professionals identify more cancers at their earliest stages, when they are most treatable.”

“Colorectal cancer is largely preventable if caught early, yet barriers to screening tests remain. It can be especially challenging for underserved populations to get screened. These barriers include lack of healthcare access, limited capacity in healthcare systems, transportation challenges, childcare, and lack of paid leave from work,” said Anjee Davis, MPPA, president of Fight Colorectal Cancer. “As the research continues to progress for blood-based tests, the availability of a test like this is a welcomed addition to the tools we can use to prevent cancer. This has the potential to improve access to screening for underserved populations and dramatically improve overall screening rates.”

Related Links:
Guardant Health, Inc.