Trial of multi-cancer blood test among 142,000 NHS patients fails to meet main aim | Cancer research
A blood test for more than 50 types of cancer, heralded as the holy grail of oncology, failed its primary purpose in a major clinical trial, according to data presented at the world’s largest cancer conference.
The aim of the study, which involved 142,000 NHS patients in the UK, was to assess whether adding the multiple cancer early detection test Galler to standard screening could shift diagnoses to earlier, more treatable stages.
But results from the trial, released for the first time on Saturday, showed it failed to meet its primary endpoint, which was to reduce late-stage cancer diagnoses.
Findings from the world’s first randomized controlled trial of a multiplex cancer early detection (MCED) test were presented to doctors, scientists and cancer experts at the American Society of Clinical Oncology (Asco) annual meeting in Chicago.
Asco’s chief medical officer and vice president, Dr. Julie Gralow said: “Although the results of the Galleri-NHS trial showed some encouraging trends towards tumor downstaging, it is important to recognize that the trial did not statistically reduce late-stage cancers relative to the predefined primary endpoint.”
A senior cancer official, speaking to the Guardian on condition of anonymity, put it more clearly. “The case failed,” the delegate said. “Plain and simple.”
142,942 people aged 50 to 77 with no signs of cancer participated in the trial. Each participant had blood drawn and recommended cancer screening tests performed annually for three years.
Half of them had their blood samples examined using the Galleri test. The other half were in the control group and their blood was not analyzed by the test.
Those who received positive results from the Galleri test in the first group consulted a doctor for a diagnostic study, as did everyone in both groups who developed cancer-related symptoms.
The trial aimed to evaluate the composite primary endpoint of stage three and stage four diagnoses in 12 prespecified cancer groups when the Galleri test was added to standard of care screening versus standard of care screening alone.
But the results showed there was no statistically significant reduction in stage three to four advanced cancers among those who had the Galleri test compared with those who did not.
On Saturday, Grail, the California-based company behind the test, said it was encouraged by other findings from the trial. The researchers highlighted that data looking only at stage four cancers dropped by 14%; This suggested that the deadliest cancers were being detected at an earlier stage.
“Grail represents a potential transformational change in cancer detection,” said Grail chief scientific officer Harpal Kumar, former chief executive of Cancer Research UK.
But experts not involved in the trial were more skeptical.
Prof Richard Houlston, head of genetics and epidemiology at the Institute of Cancer Research (ICR), London, said: “This is the largest randomized trial ever to evaluate blood testing for the early detection of multiple cancers. However, the researchers presented their findings in a much more positive light than the overall results warrant.”
“The primary goal of the study was to show a reduction in late-stage cancers overall, and this primary endpoint was not met. While some secondary findings are encouraging, these results remain unclear in terms of a possible reduction in the most advanced cancers after repeated rounds of screening and should be interpreted with caution.”
He added: “Failure to meet the primary endpoint is the crux of the problem here. Mortality results will be available within a few years and will need to be reviewed.”
“However, based on results from this and smaller trials, there is no evidence base to justify application of Galleri on a population scale.”
Prof Peter Johnson, NHS England’s national clinical director for cancer, said: “We look forward to seeing the data from the trial in detail to help us decide what this might mean for the NHS in the future.”
