Blood test to detect cancer at early stage. UK prepares to study the possibility

By Rahul Vaimal, Associate Editor
Blood Image
Representational Image

The National Health Service (NHS) of the United Kingdom is piloting a simple blood test that can diagnose more than 50 types of cancer which is hoped to benefit thousands of people by enabling the disease to be treated at an earlier stage more effectively.

The Galleri blood test, developed by Californian healthcare company Grail, will be piloted with 165,000 patients in what the NHS described as a “world-first deal” in a news release.

The study is funded by investors such as tech billionaire Bill Gates and Amazon founder Jeff Bezos. The blood test would be particularly useful in detecting types of cancer that are currently difficult to detect and treat early, NHS England hopes.

“Early detection, particularly for hard-to-treat conditions like ovarian and pancreatic cancer, has the potential to save many lives,” said NHS chief executive Simon Stevens.

Every year nearly 1.5 million people die due to cancer globally.

Pilot program

The pilot program will include 165,000 participants, including 140,000 aged 50 to 79 who have no symptoms but will have annual blood tests over three years. The study is expected to start in mid-2021.

The remaining 25,000 volunteers will be individuals with potential cancer symptoms who will be given a blood test to speed up their diagnosis after they are normally referred to the hospital, the news release said.

Results are anticipated by 2023, after which it is hoped that one million people will undertake the test by 2025, thereafter extending this to the broader population, NHS England said.

Globally, around half of cancers are currently diagnosed at stage one or two but the NHS aims to increase that to three quarters by 2028, the news release said.

According to data, adding Galleri to existing standard of care has the potential to decrease the number of cancers diagnosed at late stage by nearly half, which could reduce the total number of cancer deaths in the UK by approximately one-fifth.

Lawrence Young, a professor of molecular oncology at Warwick University, said the Galleri test was one of a number of novel blood tests being developed to diagnose cancer at a very early stage when it is easier to treat.

“There are a number of trials evaluating this approach and a publication from the Circulating Cell-free Genome Atlas (CCGA) consortium examining the Galleri test in 6,689 participants has generated very encouraging results in more than 50 different cancers at different stages of development,” he said.

Pessimistic views

However, not all cancer experts agree that the NHS should pilot the Galleri blood test. Paul Pharoah, Professor of Cancer Epidemiology at the University of Cambridge, said he had concerns about the pilot’s scientific basis, based on the limited availability of published research.

“The Galleri blood test is a test that might be able to detect cancer in the blood in individuals with early cancer, though the evidence that it does this effectively is weak,” he said. “The NHS should not be investing in such a test before it has been adequately evaluated in well-conducted, large-scale clinical trials.”

Dr. Jodie Moffat, head of early diagnosis at Cancer Research UK, said results so far from studies outside the UK had been promising. “But the sample sizes, particularly for some cancer types, have been very small and so it needs to be tested in a much larger sample, and with longer follow up of patients not testing positive with the blood test to understand where it is missing cancers,” she said.

“Based on the evidence we have seen, the test is not currently that good at picking up stage I cancer, where it is small and hasn’t spread to other parts of the body,” she added.

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