Exciting results from blood test for 50 cancers
Blood tests may help speed diagnosis for more than 50 types of cancer, according to a new study.
Results from a North American trial show that the test can detect a wide range of cancers, three-quarters of which have no screening programme.
More than half of cancers are detected at an early stage, when they are easier to treat and potentially curable.
The Galleri test, made by the American pharmaceutical company Grail, can detect cancerous DNA fragments broken off from a tumor and circulating in the blood.
The trial followed 25,000 adults from the United States and Canada for a year.
Almost 1 in 100 of those tested had a positive result, and 62% of these cancers were later confirmed to have a cancer diagnosis.
The test correctly ruled out cancer in more than 99% of those who tested negative.
When combined with breast, bowel and cervical screening, the number of cancers detected increased sevenfold.
It is very important that three quarters of the detected cancers, such as ovarian, liver, stomach, bladder and pancreas, are seen in people who do not have a screening program.
The blood test correctly identified the origin of the cancer in 9 out of 10 cases.
These impressive results suggest that blood testing may eventually play an important role in detecting cancer early.
Scientists not involved in the study say more evidence is needed to show whether the blood test reduces deaths from cancer.
Main results will be announced at: European Society of Medical Oncology congress in Berlin, but full details have not yet been published in a peer-reviewed journal.
Much will depend on the results of a three-year study involving 140,000 NHS patients in England, to be published next year.
The NHS had previously said it would expand testing to another million people if the results were successful.
Principal investigator, Oregon Health and Science University Associate Professor of Radiation Medicine Dr. Nima Nabavizadeh said the latest data shows the test “could fundamentally change our approach to cancer screening, helping to detect many types of cancer earlier, when the chances of successful treatment and even cure are best.”
But Clare Turnbull, Professor of Translational Cancer Genetics at the Institute of Cancer Research London, said: “Data from randomized trials that include mortality as an endpoint will be absolutely necessary to determine whether detection by Galleri at an apparently earlier stage provides a mortality benefit.”
Sir Harpal Kumar, Head of Biopharma at Grail, told the BBC: “We think these results are very convincing. The opportunity before us is that once we have more effective and potentially curative treatments, we will be able to find many more cancers – and many of the more aggressive cancers – at a much earlier stage.”
Naser Turabi, from Cancer Research UK, said: “More research is needed to prevent over-diagnosis of cancers that may not cause harm. The UK National Screening Committee will play a critical role in reviewing the evidence and deciding whether these tests should be accepted by the NHS.”
