Scientists are “one step closer” to being able to detect lung cancer early using just a blood test, experts have said.

Initial evidence from an ongoing study suggests a “liquid biopsy” may help spot the first signs of the disease, which is the third most common cancer in the UK.

Three sequencing techniques, analysing cell-free DNA in the blood, were between 38% and 51% accurate at detecting early-stage lung cancers, the research found.

The methods, which look for mutations and genomic changes, were up to 89% effective in detecting late-stage lung cancers.

There is an unmet need globally for early detection tests for lung cancer that can be easily implemented by health care systemsGeoffrey Oxnard

The findings, presented at the American Society of Clinical Oncology (ASCO) annual meeting, have been hailed by charities as a “very promising” development.

The initial report, which involved 127 people with stage one to four lung cancer, is part of the larger Circulating Cell-Free Genome Atlas (CCGA) study.

Lead author Geoffrey Oxnard, associate professor of medicine at Dana-Farber Cancer Institute and Harvard Medical School in Boston, said: “We’re excited that initial results from the CCGA study show it is possible to detect early-stage lung cancer from blood samples using genome sequencing.

“There is an unmet need globally for early detection tests for lung cancer that can be easily implemented by health care systems.”

Commenting on the results, ASCO expert David Graham said: “We’re one step closer to being able to detect early lung cancer from a simple blood test.

“While there’s still a way to go before cell-free DNA from blood can be used for cancer detection on a broad scale, this research serves as a building block for the development of future tests.”

So-called “liquid biopsies” are already used to help choose targeted treatments in patients with advanced lung cancer.

Professor Stephen Spiro, honorary medical adviser to the British Lung Foundation said: “This study is very promising.

“With any new research it’s important for it to be backed up with additional evidence. And, in this case applied to a high risk group to show how effective it would be in detecting cancer at its earliest stage.”

He added: “This research, with more development, could provide a breakthrough in diagnosis.”

Itâs too early to tell if a cancer blood test will work. Find out why in our news digest: https://t.co/3UbiUdquOU pic.twitter.com/xaW0WHYXxc — Cancer Research UK (@CR_UK) June 2, 2018

Dr Jodie Moffat, Cancer Research UK’s head of early diagnosis, said: “It’s exciting to think that one day we could offer people a blood test to find lung cancer earlier, meaning they could benefit from treatments which give them a better chance of beating the disease.

“This research takes us towards that but there’s still a way to go.

“We need to work out why these blood tests failed to spot lung cancer in around half of cancer patients with early stage disease, whether it’s effective in people without symptoms, and ultimately whether it can save lives.”

PA