The Food and Drug Administration is evaluating a blood test that could transform cancer screening, potentially clearing the way for a single vial of blood to detect traces of up to 50 different cancers at once. Known as Galleri, the test is under review as a breakthrough device, and an FDA decision could come later this year. If approved, experts say the technology could make routine screening far simpler, more comprehensive and more accessible than the current system of separate tests for individual cancers.
Today, standard U.S. screening covers only five cancers: breast, colon, cervical, prostate and lung. Each requires its own procedure, such as a mammogram, colonoscopy or Pap smear. By contrast, Galleri and a similar test called Cancerguard from Exact Sciences analyze DNA fragments and other markers in the blood to signal the possible presence of many cancers at once. The tests do not diagnose cancer but instead tell doctors where in the body to look more closely. “It’s a real fundamental shift in how we think about cancer screening,” said Megan Hall, vice president of medical affairs for Grail, the company that developed Galleri. “Instead of screening for individual cancers, we can now screen an individual for multiple cancers simultaneously.”
Both tests are already available in the U.S. under a special FDA designation, but full approval would allow Medicare and other insurers to cover them. In February, Congress passed legislation that will allow Medicare to reimburse multi-cancer early detection tests starting in 2028. Grail sets the retail price for Galleri at $950; Cancerguard costs $659. Grail is conducting two large population studies: one involving more than 142,000 patients in the U.K. and another with 35,000 patients in North America. While the U.K. study did not meet its primary goal of a significant reduction in late-stage cancers overall, combined data from both trials showed a 26% reduction in Stage 4 cancers in the third year, including pancreatic, liver, lung and gastric cancers. The company emphasizes that the test is meant to complement, not replace, existing screenings.
What This Means for Patients and the Future of Cancer Care
Oncologists say the simplicity of a blood test could make screening easier for people who currently skip recommended exams. Dr. Arif Kamal, chief patient officer at the American Cancer Society, noted that Grail is one of hundreds of companies pursuing blood-based detection. “The science is sound and the technology is solid,” he said, adding that the main question is how quickly it will evolve. Similar technology, often called liquid biopsies, is already used to monitor patients with diagnosed cancers, helping doctors see if treatment is working or if the disease is returning. Dr. Jonathan Goldman, a lung cancer specialist at UCLA, said blood-based testing “has become central to the way that we think about lung cancer and other cancers because the systems have become so sensitive.”
Looking ahead, researchers envision even more sensitive tests that could one day predict a person’s risk of developing cancer years in advance. For now, the focus is on catching cancers earlier, when they are more treatable. Hall noted that advances in cancer treatments over the past decade mean that catching a cancer at Stage 3 versus Stage 4 has never been more significant for survival. “The treatment landscape has evolved so much over the past five to 10 years, that there are now a lot of treatments even for Stage 3,” she said. “And that’s a really big deal.”