A blood test that could detect 50 types of cancer has shown ‘promise’ in early trials, scientists said — after it spotted the disease in previously healthy people.
New York-based scientists detected 35 cases of cancer using the test, but another 57 people were wrongly diagnosed with the condition.
It was not possible to determine its accuracy because the 6,000 participants were not screened using standard tests at the same time.
The Galleri blood test uses a single swab to look for a signal made by many cancers, including types affecting the breasts, lungs and kidneys. Scientists say it has great promise in detecting some cancers — like pancreatic — early, whereas current tests can only detect them in later stages when survival chances are reduced.
It is available on prescription for $949-a-pack, but experts say the test should not be used in place of standard screening procedures.
Scientists at the Memorial Sloan Kettering Cancer Center who carried out the research said although the test was good, it still needed to be refined. It comes just a day after President Joe Biden unveiled plans to halve cancer deaths to 300,000 a year by 2042 by piling millions of dollars into developing blood tests for it.
New York-based scientists detected 35 cases of cancer using the test, but another 57 people were wrongly diagnosed with the condition
The study results were presented today at the annual Congress of the European Society for Medical Oncology (ESMO) held in Paris, France.
The trial recruited 6,621 people over the age of 50 years old who were otherwise healthy.
Each had a blood sample taken which was run through the Galleri test to check for cancers.
How does the Galleri cancer test work?
The Galleri cancer test works by screening the blood for signals that could indicate cancer.
Its developers say the test can detect over 50 types of cancer, including ones that are usually only picked up in late stages by routine screening.
It works by looking for chemical changes in fragments of genetic code – cell-free DNA (cfDNA) – that leak from tumors into the bloodstream.
Some cancer tumors are known to shed DNA into the blood a long time before a person would start experiencing symptoms.
Galleri says it takes around 10 days to turn around a test.
They add that their test should be used in conjunction with normal screening programs.
Scientists found in clinical trials that the test detected cancer correctly in 51.5 per cent of cases.
The test is available on prescription in the U.S. for about $949-a-pack.
The tests work by searching for cancer signals in the blood dumped by tumors, and is able to pick up more than 50 types because each makes the same distinct signal.
Results showed 92 patients tested positive for cancer.
But after each was put through routine screening it emerged only 35 (or 38 percent of the total) actually had the disease.
Separate screening was not carried out at the time to check the patients who got the all-clear for some cancers.
But a year after the trial 86 more participants were diagnosed with cancer.
It was not clear whether they already had the cancer at the time the test was carried out, or if it was not present when the test was done.
Fourteen of the cancers detected were in stage I or II — when they are easier to treat —, and seven were found in people who had cancer in the past.
A type of circulatory cancer called lymphoma was the most common detected (12 patients), followed by cancer of the breasts (five), blood (three), colon and rectum (two), prostate (two) and throat (two).
There was also one case of liver, pancreatic, small intestine, ovary, uterus, bone, plasma cell and bile duct cancer.
And one patient who tested positive using the tests was found to have both breast and uterus cancer, the scientists said.
Data was not collected on whether the survival chances of patients improved thanks to the earlier diagnosis.
Commenting on the research, a release from the ESMO conference said the test showed ‘promise’ in the study.
Dr Deb Schrag, the oncologist who led the research, said: ‘This study indicates that hope is on the horizon for detecting cancers that are currently unscreenable, but of course much more work is needed and, with experience and larger samples, this will improve.
‘The tests need to be refined so they are better at distinguishing tumor DNA from all the other DNA that is circulating in the blood.’
It comes after Biden announced a boost for his ‘cancer moonshot’ programme yesterday saying he planned to halve deaths from it over the next two decades.
To achieve this the President said he would funnel millions of dollars into developing diagnostic tests for cancer. The final amount is yet been revealed.
The battle against cancer is personal for Biden who lost his son Beau to brain cancer in 2015.
