‘Holy grail’ blood test for more than 50 cancers delivers ‘exciting’ results | UK | News

A blood test that screens for more than 50 cancers and is being trialled on the NHS was accurate in 62% of cases where people thought they might have the disease, a study has found.

The Galleri test, which can be done every year, looks for the “fingerprint” of dozens of deadly cancers, often catching symptoms before they appear.

It works by identifying DNA in the bloodstream that has been shed by cancer cells, giving the earliest signs that a person may have the disease.

Now, a major US trial of the test has shown that Galleri is highly accurate at ruling out cancer in people without the disease, while also detecting cases of cancer at an earlier stage when the disease is more treatable.

Findings from the Pathfinder 2 study showed that 61.6% of people with a “cancer signal” detected in their blood were diagnosed with cancer.

And in 92% of cases, the test can detect in which organ or tissue the cancer originated; This means time and money can be saved on other scans and other tests.

More than half (53.5%) of the new cancers Galleri detected in the study were at the earliest stage I or II, while more than two-thirds (69.3%) were detected at stages I-III.

Called the holy grail of cancer testing, Galleri accurately ruled out cancer in 99.6 percent of people who did not have the disease.

The findings are being presented at the European Society for Medical Oncology (ESMO) Congress in Berlin.

Sir Harpal Kumar, Grail’s head of International Business and BioPharma and former head of Cancer Research UK, who led the Galleri, said the findings were impressive.

“We’re really excited and think this is a step towards truly transforming cancer outcomes,” he told the PA news agency.

The Pathfinder 2 study looked at how the Galleri test could be used in a real-world setting alongside regular screening programs for things like breast and bowel cancer.

People with no symptoms were recruited from the United States and Canada; of these, 23,161 were analyzed and had a follow-up period of at least 12 months.

The results showed that adding Galleri to regular cancer screenings led to a more than sevenfold increase in the number of cancers found within a year.

Cancer signals were detected in 216 people in the test, and 133 of them were diagnosed with cancer.

Therefore, the probability of being diagnosed with cancer following a positive test result showing a “cancer signal” was 61.6%.

Sir Harpal told PA: “What we wanted to assess was what added value does the test provide beyond existing screening?

“And one of the most important and exciting results is that it detected seven times more cancers than other screening programs combined.”

He said screening programs in the US were slightly different from those in the UK but were “comparable in the sense that screening programs are offered”.

An NHS Wales study showing how well the test works at screening people without symptoms is expected to be published in the middle of next year.

Sir Harpal said: “Assuming we get positive results from NHS Galleries, the opportunity to find many more cancers before they become clinically evident means we can find many more at an earlier stage.

“This opens up the possibility of using more effective treatments and, in many cases, curative treatments.

“This should make a significant difference to cancer outcomes.

“This is also particularly effective in types of cancer for which we currently have no other screening, and in cancers that are often diagnosed very late, such as pancreatic, head and neck, liver and ovarian.

“As a complement to existing screening, we can find many, many more cancers before they become symptomatic, which has the potential to truly transform the way we diagnose cancer and the outcomes we can expect.

“We hope that when we receive these results next year, the NHS will move very quickly to evaluation of practice in the NHS.”

Sir Harpal said the test can also identify which organ or tissue the cancer is in, making the “diagnostic process very efficient and rapid”.

Galleries can also assist doctors treating patients with vague symptoms.

Sir Harpal said: “If someone presents with abdominal pain you might ask: Is it ovarian cancer, pancreatic cancer, colorectal cancer – or is it definitely not cancer?

“If we can help clinicians direct these studies, then we can make much better use of the very scarce diagnostic capacity.”

Modeling suggests the Galleri test may be effective as an annual blood test in people over 50, when cancer cases begin to rise rapidly.

“Our analysis shows it will be more cost-effective for those aged 50 and over,” Sir Harpal said, adding that some younger people who have previously had cancer or have a genetic predisposition to the disease may also benefit.

The study, published in May in the journal BMJ Open, found that annual blood testing for cancer could lead to 49% fewer late-stage diagnoses and 21% fewer deaths over five years compared to patients receiving usual care.

Grail chief executive Josh Ofman said: “These results are extremely interesting as around three-quarters of cancers detected by galleries do not have the screening tests recommended today.”

Responding to the findings, Professor Clare Turnbull, of the Institute of Cancer Research London, said data was needed on whether tests such as Galleri’s had an impact on reducing cancer death rates.

Professor Nitzan Rosenfeld, director of the Barts Cancer Institute in London, said the results were “impressive” and the 62% figure was “very encouraging and provides strong evidence that this test can be safe and informative”.

He said more data on mortality was needed, but added: “More than 50% of cancers detected by the Galleri test in this study were early stage (stage I-II), and more than 75% of these had no common screening options.”

Anna Schuh, professor of molecular diagnostics at Oxford University, said that according to the findings, the probability of a person who tests positive actually having cancer is around 60 percent.

“Or to put it another way: almost half the time the test gets it wrong when it returns a positive result,” he said.

“This is disappointing because it is marginally better than flipping a coin, but it is better compared to current screening tests where most positive results are still nothing.”

He suggested the current detection rate might mean the NHS did not find it a cost-effective test.

He said the test sensitivity was “good for some common cancers (74%), but not so good for others (they account for more than half of all cancers in total), and clinical sensitivity for these is poor (40%).”