FDA Approves Blood Test for Detecting Colon Cancer in Individuals with Average Risk

On Monday morning, the U.S. Food and Drug Administration sanctioned a blood exam to check for colorectal cancer in specific individuals.

Shield, the blood assessment made by Guardant Health, has already hit the market, but FDA approval will expand its accessibility and coverage by insurance.

Individuals aged 45 and above with a “typical risk” of colon cancer are eligible for the exam.

Shield identifies colorectal cancer through the detection of DNA released by tumors in blood samples. Results are available approximately two weeks after the laboratory receives the samples.

Shield is not the primary blood-based screening tool accessible for colorectal cancer, and colonoscopies are still viewed as the superior method for screening.

Nevertheless, the exam offers an alternative for checking a form of cancer that has been impacting numerous Americans at younger ages than previously.

Earlier this year, the FDA advisory panel — the Medical Devices Advisory Committee (MDAC) — suggested that the federal health agency endorse the exam. Although FDA approval is not definite, the agency typically concurs with its advisors.

As per clinical trial data published in The New England Journal of Medicine, Shield demonstrated an 83.1% sensitivity rate, indicating that 83.1% of patients with colorectal cancer detected by a colonoscopy tested positive on the Shield blood test. It also displayed an 89.9% specificity rate, showing that 89.9% of patients without cancer tested negative on the blood test.

Despite the overall high sensitivity rate, the clinical trial data suggested that Shield could overlook one out of 10 individuals with precancerous lesions and one out of 1,000 individuals with cancerous lesions.

These “false negatives” may lead to tests indicating no signs of cancer when patients actually have precancerous or cancerous lesions, according to the clinical trial data.

Even though members of the MDAC expressed worries about false negatives, the committee ultimately concluded that the exam is safe and efficient, and that the advantages of its use outweigh the potential risks.

“The FDA approval of the Shield test is a significant triumph for patients and a crucial achievement in Guardant Health’s goal to defeat cancer with data. Shield can enhance colorectal cancer screening rates to aid in the early detection of more treatable cancers,” stated AmirAli Talasaz, Guardant Health co-CEO, in a press release.

“We are now preparing to introduce this exam in the near future and are very enthusiastic about providing doctors with a viable blood-based screening alternative to customize the screening process according to the unique requirements of their patients,” Talasaz added.