A new blood test may revolutionize cancer detection by rapidly identifying more than 50 types of the disease, according to a recent study conducted in North America.
The test, known as the Galleri test, was developed by the American pharmaceutical company Grail and detects fragments of DNA released from tumors into the bloodstream. Notably, it identified three-quarters of cancers that currently lack established screening programs.
In the trial, which monitored 25,000 adults across the U.S. and Canada over one year, roughly 1 in 100 participants tested positive, with subsequent confirmation of cancer in 62% of these cases. Among those who tested negative, the test correctly ruled out cancer in over 99% of participants.
Dr. Nima Nabavizadeh, head of the research team and Associate Professor of Radiation Medicine at Oregon Health & Science University, highlighted the significance of these findings. “This data could fundamentally change how we detect cancer. Early detection improves treatment outcomes and significantly raises the chance of cure,” he said. Detection rates for breast, colon, lung, and cervical cancers increased sevenfold with this test.
Crucially, the test detected cancers such as ovarian, liver, stomach, bladder, and pancreatic cancers—types for which no current screening exists—and correctly identified the source of cancer in 90% of cases. More than half of detected cancers were at an early stage, when treatment is more effective.
However, some experts urge caution. Professor Clare Turnbull of the Institute of Cancer Research in London noted that while the results are promising, it is vital to evaluate multiple studies and not focus solely on mortality. “We need to understand whether early detection via the Galleri test actually reduces cancer deaths,” she said.
The study’s main results will be formally presented at the European Society for Medical Oncology Congress in Berlin. Full peer-reviewed publication is pending. In the U.K., the National Health Service (NHS) is conducting a three-year trial involving 140,000 patients, with results expected next year. If successful, the test could eventually be offered to 1 million more people.
Sir Harpal Kumar, President of Grail’s biopharma division, emphasized on BBC Radio 4 that late detection is a key reason cancer remains deadly. “Our aim is to detect cancer early, when it is more treatable and potentially curable,” he said.
Despite the optimism, experts like Naser Turabi of Cancer Research UK stressed the importance of additional research to ensure the test’s benefits outweigh potential harms. The U.K.’s National Screening Committee will play a critical role in evaluating the acceptability and implementation of these tests.
