New Delhi, Jan 13 : A team of British scientists has found that a blood test used to detect circulating tumour DNA can predict the outcome of lung cancer.

Circulating tumour DNA (ctDNA) is fragments of DNA released into the blood by tumours. It's known to be important for disease prognosis but can be difficult to measure precisely.

In the study, scientists from the Francis Crick Institute and University College London used a whole-genome sequencing platform called NeXT Personal, which can detect very small amounts -- 1 part per million -- of ctDNA.

They used the platform to test blood plasma samples from 171 people with early-stage lung cancer.

The finding published on Monday in the journal Nature Medicine showed that people with a low level of ctDNA before surgery were less likely to relapse and had improved overall survival rates than people with a high level of ctDNA.

The high sensitivity of the test meant that smaller amounts of ctDNA could be detected, which prevented people with a lower amount of ctDNA from being incorrectly labelled ctDNA negative.

'We've shown that the presence or absence of tumour DNA in the blood was strongly predictive of prognosis. ctDNA testing, especially using ultrasensitive platforms, could help clinicians make more informed decisions about treatment and give patients a more accurate idea of how their disease might progress,' said James Black, Postdoctoral Clinical Fellow at the Francis Crick Institute.

Current treatment for early-stage lung cancer includes removing the tumour by surgery and with chemotherapy or immunotherapy. The treatment course depends on the stage of the tumour, which aims to achieve the highest chance of cure.

Meanwhile, the team noted that the test will next be assessed on samples from patients who have undergone surgery with the earliest stages of lung cancer. This will help evaluate if the presence of ctDNA post-operatively in blood can be used to infer future risk of relapse.

This could allow doctors to offer additional therapy after surgery, increasing the chance of curing patients, the scientists said.

/IANS