FDA approves first blood test for colorectal cancer screening

The U.S. Food and Drug Administration has approved the first blood test for colorectal cancer screening for average-risk adults aged 45 and older, providing a new, less invasive option for early detection.

According to a report on CNN, Guardant Health, a biotechnology company based in Palo Alto, California, announced Monday that its test, called Shield, is the first blood test approved by the FDA as a primary screening tool for colorectal cancer. This test also qualifies for Medicare reimbursement. The cost for patients with commercial insurance will vary depending on individual plan coverage, with the list price yet to be announced.

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

Colorectal cancer is the second leading cause of cancer deaths in the U.S., with over 53,000 expected fatalities this year, according to the American Cancer Society. However, about 70% of these deaths could be prevented with increased screening.

The Shield test, which detects tumor DNA in blood samples, will join other screening methods such as colonoscopies and at-home stool tests. While some patients may prefer the convenience of a blood test, others may find colonoscopies invasive or stool tests awkward.

The FDA's approval follows a positive recommendation from its Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee, which voted 8-1 on the safety, 6-3 on the effectiveness, and 7-2 on the benefit-risk balance of the test.

The Shield test has shown around 83% sensitivity and 90% specificity in a study of nearly 8,000 people, published in the New England Journal of Medicine. This means it accurately identified 83% of those with colorectal cancer and correctly ruled out 90% of those without the disease. However, its sensitivity in detecting precancerous lesions was significantly lower, around 13%.

Dr. Daniel Chung, a gastroenterologist at Massachusetts General Hospital, emphasized the importance of this new screening option. “The FDA’s approval of the Shield blood test marks a tremendous leap forward, offering a compelling new solution to close the gap in colorectal cancer screening rates,” Chung said. “With increased screening rates and early cancer detection, many more lives can be saved.”

Despite the availability of existing screening methods, more than one-third of adults aged 50 to 75 are not getting screened as recommended, according to the National Colorectal Cancer Roundtable. The U.S. Preventive Services Task Force recommends starting colorectal cancer screening at age 45 for people at average risk.

While blood tests like Shield may not identify precancerous polyps as a colonoscopy would, they offer an alternative for those who might otherwise forgo screening. “You have to give people a choice,” said Robert Smith, senior vice president of early cancer detection science at the American Cancer Society.

The Shield test is expected to launch commercially within the next week, expanding the tools available to fight colorectal cancer.

[Information sourced from CNN]