In a development, Guardant Health’s Shield™ blood test has received approval from the U.S. Food and Drug Administration (FDA) as a primary screening option for colorectal cancer (CRC) in adults aged 45 and older who are at average risk. This marks the first time a blood test has met the stringent performance requirements for both FDA approval and Medicare coverage, signaling a significant shift in CRC screening practices.
The American Cancer Society predicts over 150,000 new CRC cases and more than 53,000 deaths from the disease in 2024. Despite the high treatability of CRC when detected early, current screening rates remain alarmingly low, with only about 59% of eligible individuals undergoing screening. This is far below the National Colorectal Cancer Roundtable’s goal of 80%.
One of the major barriers to CRC screening has been the invasiveness and inconvenience of traditional methods like colonoscopies and stool-based tests. Dr. Daniel Chung, a gastroenterologist at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School, highlighted the persistent gap in screening rates, emphasizing that many people find existing options unpleasant or impractical.
“The FDA’s approval of the Shield blood test marks a tremendous leap forward,” said Dr. Chung. “This decision will help make screening tests more broadly accessible and propel blood-based testing and CRC screening into a new era. With increased screening rates and early cancer detection, many more lives can be saved.”
The Shield test, developed over a decade of research and collaboration with leading health organizations, offers a simple and non-invasive alternative to traditional CRC screening methods. Patients can complete the test with a routine blood draw during a regular office visit, eliminating the need for special preparation, dietary restrictions, or the discomfort associated with colonoscopies and stool tests.
The test has shown promising results in clinical settings, with a real-world adherence rate of over 90%, significantly higher than the 28-71% completion rates for other screening methods. This high adherence rate indicates that more patients are likely to complete the Shield test, potentially leading to earlier detection and better outcomes.
The FDA’s approval was based on the results of the ECLIPSE study, a comprehensive trial involving over 20,000 patients across 37 states. The study demonstrated Shield’s high accuracy, with 83% sensitivity for detecting CRC and 90% specificity for advanced neoplasia. These results are comparable to other non-invasive screening methods currently recommended by guidelines.
Dr. William M. Grady of the Fred Hutchinson Cancer Center praised the test’s potential, noting that its accuracy for colon cancer detection is similar to existing stool tests, offering a viable alternative for patients who might otherwise skip screening.
Patients like Dennis Barnes and John Gormly have already experienced the benefits of the Shield test. Barnes, a busy attorney, opted for the Shield test during a routine physical after repeatedly postponing a colonoscopy. “The Shield test is a much more pleasant way to screen, and the convenience of it makes getting screened pretty much a no-brainer,” he said.
Gormly, a 77-year-old business executive, was diagnosed with stage II colon cancer after a positive Shield test result led to a follow-up colonoscopy. “Thank God I had taken that blood test,” he remarked, crediting Shield with facilitating early detection and treatment.
Guardant Health is preparing to launch the Shield test broadly, with plans for Medicare coverage and anticipated guideline inclusion by the American Cancer Society and the U.S. Preventive Services Task Force (USPSTF). AmirAli Talasaz, co-CEO of Guardant Health, expressed excitement about the potential impact on CRC screening rates and early cancer detection.
“The FDA approval of the Shield test is a significant victory for patients and an important milestone in Guardant Health’s mission to conquer cancer with data,” Talasaz said. “We are now getting ready to launch this test and empower physicians with a viable blood-based screening option tailored to the unique needs of their patients.”