On Jan. 13, 2025, scientists from the Francis Crick Institute, UCL, UCLH and Personalis announced they have found that a test to detect circulating tumour DNA can predict lung cancer outcome in a Cancer Research UK-funded study. 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.

Crick and UCL scientists worked with Personalis to test a platform called NeXT Personal, which can detect very small amounts – 1 part per million – of ctDNA. This builds on the Crick team’s discovery of signals in the blood that detect cancer cells after treatment, which could indicate a potential for relapse. 

They applied the platform to blood plasma samples from 171 people with early-stage lung cancer in the TRACERx cohort, finding 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.

The test will next be assessed on samples from patients that have undergone surgery with the earliest stages of lung cancer, to 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 research was published in Nature Medicine.