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Blood Test for 50 Cancers Coming to U.S. Clinics Soon

vials of blood

Editor's note: This story was updated on May 18, 2021, with an additional comment from the company.

May 17, 2021 -- A new blood test called Galleri, made by Grail Inc., which claims to find up to 50 different cancers from single blood draw, is about to make its debut in the United States. However, an expert cautions that this test should be considered as being under clinical investigation.

Providence Health System, based in Renton, WA, will be the first health system in the U.S. to offer access to the Galleri test, where it will be available as a complement to recommended single-cancer screening tests.

The test will initially be used by Providence at its California, Washington, and Oregon points of care, Grail notes. From there, it could eventually be available across the entire Providence system, which covers six states (Alaska, Montana, and Texas are the others) and includes more than 50 hospitals and nearly 1,100 health clinics serving 5 million patients.

On its website, GRAIL notes that the Galleri blood test is recommended for adults with an elevated risk for cancer, such as those aged 50 or older. It is intended to detect cancer signals and to predict where in the body the cancer signal is located.

But it does not detect all cancers, and Leigh Strope, director of corporate communications at Grail, says that it's "intended to be used in addition to, and not replace, other cancer screening tests." The company also notes that results from the blood test "should be interpreted by a healthcare provider."

As of now, the Galleri test has not been cleared or approved by the FDA.

Not Ready for the Clinic?

An expert approached for comment believes that the test is not ready for clinical use. William Grady, MD, a member of the Clinical Research Division and Public Health Sciences Division at the Fred Hutchinson Cancer Research Center in Seattle, tells Medscape Medical News that this test should be viewed as one that is still under clinical investigation.

"The Galleri test is still unproven in the clinical care setting and should not be considered as equal in performance to approved tests for cancer screening," he says.

"I am concerned that many of the results will be false-positives and will cause many unnecessary follow-up tests and imaging studies as well as anxiety in the people getting the test done," Grady says.

"This tests for a whole array of different cancers, but one reason that we don't do screening for rare cancers in the general population is that the false-positive result is so high," Grady says. "I am hoping that they will run it in a population who are already getting screened and then compare it with the results of routine tests, to get a sense of how accurate it is."

Grady says that it is interesting that Grail is partnering with a U.S. health care system, but he emphasized that this has to be viewed as a clinical trial.

The test is already in use in the United Kingdom, but only in a pilot trial run by the National Health Service England. Announced in December, this trial involves 165,000 people divided into two groups: The first will include 140,000 people over the age of 50 without any suspected cancer; the second will include 25,000 people aged 40 and above with suspicious signs of cancer. Based on data from this program, access to the test could be expanded to approximately 1 million people across 2024 and 2025 and may roll out to a larger population thereafter, the company says.

More Studies on the Way

In response to the concerns raised above by Grady, Grail tells Medscape Medical News that the Galleri test has a false-positive rate of less than 1%, based on published peer-reviewed data from large-scale clinical studies.

Grail notes it is collecting more clinical data, with over 134,000 participants enrolled to date across five clinical studies.