FDA approves colorectal cancer blood test

On July 29, 2023, the United States Food and Drug Administration approved Guardant Health Inc.’s Shield blood test for colorectal cancer, expanding the diagnostic tools for this type of cancer beyond the existing options. The tool has been approved for individuals ages 45 and older who are at average risk for colorectal cancer.

“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. Shield can help improve colorectal cancer screening rates so we can detect more cancers at an early stage, when they are treatable,” said AmirAli Talasaz, Guardant Health co-CEO, in the press release. “We are now getting ready to launch this test in the near future and are very excited to empower physicians with a viable blood-based screening option to tailor the screening regimen to the unique needs of their patients.”

According to Gaurdant’s press release, this noninvasive screening tool is comparable to other options recommended in the screening guidelines for this condition. Additionally, it will meet the requirements for Medicare coverage.

The Shield blood test is a compilation of over a decade of research and development from Guardant and other health organizations. It is a cell-free DNA (cfDNA) blood-based test.

A study validating the test and supporting its approval was published in the New England Journal of Medicine in March 2024. Researchers looked at a cohort of 7,861 people who were eligible for screening with the test. They found that it detected 83.1% of colorectal cancers, indicating an 83.1% sensitivity.

More specifically, researchers found that the sensitivity for stage I, II, and III colorectal cancer is 87.5%, while the sensitivity for advanced precancerous lesions was much lower at 13.2%.

“This is a promising step toward making more convenient tools available to detect colorectal cancer early while it is more easily treated,” said William M. Grady, MD, a gastroenterologist at Fred Hutchinson Cancer Center. “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."

There has been a lot of attention on screening tools for colorectal cancer as the rates of the disease continue to rise across the US.