Cheap blood test detects lung cancer at an early and treatable stage

Lung cancer screening has always been expensive, but a simple blood test that detects lipids associated with tumours may offer a cheaper alternative

By Alice Klein

A blood test that can detect lung cancer before people get symptoms may save lives by allowing early treatment.

Lung cancer has a 63 per cent survival rate if it is caught early and hasn’t spread to other parts of the body. Once it spreads, the survival rate drops to 7 per cent.

Catching lung cancer early is difficult because we don’t have any cheap, simple ways to screen for it. Chest CT scans can be used to look for tumours in the lungs, but they are expensive, expose people to radiation and can sometimes make false detections.

Jun Wang at Peking University in Beijing, China, and his colleagues discovered a new way to detect lung cancer by checking people’s blood for unusual levels of nine different lipids – fatty molecules that are present in unusual amounts in tumours.

They trialled the blood test in 1036 people over the age of 40 who didn’t have symptoms of cancer and were going for an annual physical examination. The test was over 90 per cent accurate at detecting those with lung cancer, as determined by a CT scan of each participant’s chest.

The 13 individuals who were found to have lung cancer – mostly early stage – were treated by surgically removing their tumours.

A benefit of the test is that it takes less than 90 minutes to complete, from taking a person’s blood to running it through a mass spectrometry machine to measure lipid levels and crunching the data, says Wang.

The test is also relatively cheap and doesn’t expose people to any radiation, he says.

Kwun Fong at the Prince Charles Hospital in Brisbane, Australia, says the blood test looks promising and could potentially be used to screen people who are at high risk of developing lung cancer – for example, those who have a family history or are heavy smokers.

This in turn could save lives by identifying cancers at a stage where they can still be curatively treated with surgical removal or radiation, says Fong.

“[The test] needs to be validated in other populations first, but if it performs as well, it could be used in addition to CT screening or possibly as a replacement,” he says.

Journal reference: Science Translational Medicine, DOI: 10.1126/scitranslmed.abk2756

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