Blood test offers new hope for lung cancer

BRITAIN: Scientists in Britain have developed a blood test which detects the recurrence of lung cancer in patients up to a year before the disease can be detected by CT scans and X-rays.

The groundbreaking TRACERx study, funded by Cancer Research UK and published in the science journal Nature, identified the cause of relapse of the disease and how it spreads, in a discovery that could lead to earlier treatment for patients.

By analysing tumours from 100 lung cancer patients, researchers at medical research centre the Francis Crick Institute found that those containing a higher proportion of ‘‘unstable chromosomes’’ - those which cause genetic chaos and allow the tumour to evolve - were four times more likely to have a relapse or die within two years.

Genetically diverse tumours are harder to treat, as they are more likely to spread and become drugresistant.

In a study using 96 of those 100 patients, scientists screened their blood for circulating tumour DNA - bits of DNA that had ‘‘broken off’’ from a tumour - in order to uncover defects present in the patient’s cancer.

They used this information to analyse blood samples from 24 patients who had undergone surgery, and were able to identify more than 90 per cent of cancer cases likely to return, up to a year before other clinical methods, such as CT scans or an X-ray, could detect the illness.

Scientists also compared the levels of tumour DNA in patients’ blood before and after post-surgery chemotherapy. They found that the cancer returned when levels of tumour DNA were not reduced, showing that the tumour had become partially resistant to the chemotherapy.

The findings could pave the way for the development of new drugs to target resistant parts of lung cancer tumours. - PA