Liquid biopsy could detect breast cancer recurrence earlier than scan

A newly developed blood test can spot breast cancer relapses almost a year before they are clinically detectable.

In a study published in Jama Oncology, researchers showed that blood samples from a combined cohort of 144 breast cancer patients predicted cancer recurrence about 11 months before symptoms appeared or secondary tumours were detected using scans. 

Professor Nicholas Turner, the lead author on the study, said: 'These new blood tests can work out which patients are at risk of relapse much more accurately than we have done before, identifying the earliest signs of relapse almost a year before the patient will clinically relapse.'

The personalised 'liquid biopsy' was developed by scientists at the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust, in London. The test can detect small amounts of cancer DNA in a patient's blood sample, by matching the DNA in the blood to that found in the original tumour sampled before treatment. The study found that the test works in all types of breast cancer and could potentially be used to monitor how a patient’s cancer is responding to treatment in real-time and spot recurrences.

In the UK, around 55,000 people develop breast cancer every year and in 2016, more than 11,500 people died from the disease. If the cancer returns and spreads after treatment it can be controlled for some time but cannot generally be cured, accounting for most deaths. While this blood test may detect relapses earlier, whether this will help these as-yet incurable patients is not clear. 

Professor Turner said: 'We hope that by identifying relapse much earlier we will be able to treat it much more effectively than we can do now, perhaps even prevent some people from relapsing.'

Further research is needed to establish if the test could be used in the clinic to help guide treatment and improve patient outcomes.

Dr Simon Vincent, director of research at the charity Breast Cancer Now, which provided most of the funding for the study, said: 'The potential of this blood test to in future spot the signs of breast cancer returning or spreading much earlier in NHS clinics is extremely exciting. But we now need upcoming trials to identify whether offering treatments to patients at this stage could actually help intervene and improve their chances of survival or quality of life.'