The U.S. Food and Drug Administration (FDA) has approved a new blood test for colorectal cancer (CRC) screening for adults ages 45 and older who are at average risk for the disease, according to a statement from Guardant Health Inc.
The FDA’s decision follows a strong recommendation for approval from an advisory committee panel in May 2024.
The approval of Guardant Health’s “Shield” test marks the first time that a blood test has been recognized by the FDA as a primary screening option for CRC, offering a noninvasive alternative to traditional methods such as colonoscopies and stool-based tests, according to the statement.
Colorectal cancer is the second-leading cause of cancer-related deaths in the United States, with the American Cancer Society estimating more than 150,000 new diagnoses and 53,000 deaths in 2024 alone.
Early detection is crucial, as the five-year relative survival rate is 91 percent when CRC is identified early, compared with just 14 percent if the cancer has spread to distant parts of the body, according to the company’s statement.
The screening rate for CRC in the United States stands at about 59 percent, significantly below the National Colorectal Cancer Roundtable’s goal of at least 80 percent. Many people avoid traditional screening methods because of their invasive and unpleasant nature, according to the statement.
“The persistent gap in colorectal cancer screening rates shows that the existing screening options do not appeal to millions of people,” Dr. Daniel Chung, a gastroenterologist at Massachusetts General Hospital and professor of medicine at Harvard Medical School, said in the statement.
“The FDA’s approval of the Shield blood test marks a tremendous leap forward, offering a compelling new solution to close this gap. 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 blood test has been in development for more than a decade, according to the company.
A major clinical trial, the ECLIPSE study, demonstrated that the Shield test has an 83 percent sensitivity for detecting CRC and a 90 percent specificity for advanced neoplasia, according to the company. The results are comparable to those of other noninvasive screening methods currently recommended by guidelines, according to the statement.
“Shield can help improve colorectal cancer screening rates so we can detect more cancers at an early stage, when they are treatable,” Guardant Health Co-CEO AmirAli Talasaz said in the statement.
The advisory committee panel acknowledged the test’s reliability for detecting stages 2, 3, and 4 CRC and emphasized the benefit of having a blood test that can achieve higher adherence rates among patients who avoid colonoscopies or stool-based tests. However, it stressed that Guardant Health must make sure that consumers are aware that the blood test is not equivalent to a colonoscopy in its ability to detect and remove benign polyps before they can become cancerous.
The panel highlighted the importance of clear labeling and patient education to mitigate risks associated with the test’s lower sensitivity for detecting pre-cancerous advanced adenomas, according to the minutes from the panel’s meeting.
The panel noted that patients with pre-cancerous advanced adenomas have a high risk of developing CRC and that Shield’s lower test sensitivity for detecting these adenomas means that there is a risk that patients might receive a negative test result despite having pre-cancerous advanced adenomas, potentially leading to missed opportunities for early intervention.
The panel said it’s crucial that the test’s limitations were clearly communicated for patients to understand that while the Shield test is an effective tool for CRC screening, it “is not a replacement for diagnostic colonoscopy or for surveillance colonoscopy in high-risk individuals.”
Guardant Health’s Shield test will be available by prescription and is expected to be covered by Medicare for eligible beneficiaries. Commercial insurance coverage is also anticipated to expand following future guideline inclusions by the American Cancer Society and the U.S. Preventive Services Task Force, according to the statement.
“The test, which has an accuracy rate for colon cancer detection similar to stool tests used for early detection of cancer, could offer an alternative for patients who may otherwise decline current screening options,” said Dr. William M. Grady, a gastroenterologist at Fred Hutchinson Cancer Center.
