A groundbreaking cancer blood test which is ten times more sensitive in identifying DNA changes in patients could help predict relapses.
Current ‘liquid biopsy’ tests can detect around one genetic mutation in 10,000 pieces of DNA and may return a negative result even if the cancer is still lurking and could flare up.
While this is like searching for a “needle in a haystack”, according to University of Cambridge researchers, this new technique can routinely pick up one genetic mutation in 100,000 pieces of DNA, making it much less likely they slip under the radar.
Mutations in tumour DNA (ctDNA) can vary between patients, and the test can pick up on many different ones up to 12 months earlier than possible with imaging tests.
It is hoped the test will determine to a significantly higher accuracy whether a patient’s cancer is going to return following treatment.
The researchers studied blood samples from 105 cancer patients with five different types of cancer at varying stages of progression.
They found that the test was highly sensitive in detecting genetic mutations in patients with advanced breast and skin cancer, those with very early stage cancer which would normally be difficult to detect, and patients with glioblastoma – which is notoriously difficult to identify in the blood.
Dr Nitzan Rosenfeld, who led the research team, said: “Whilst this may be several years away from clinical use, our research shows what is possible when we push such approaches to an extreme.
“It demonstrates that the levels of sensitivity we’ve come to accept in recent years in relation to testing for ctDNA can be dramatically improved.
“At present this is still experimental, but technology is advancing rapidly, and in the near future tests with such sensitivity could make a real difference to patients.”
This breakthrough could pave the way for less blood being required for testing and the introduction of finger prick tests which patients can carry out themselves at home, revolutionising the way cancer is monitored.
It would not only result in fewer trips to hospital, but also more frequent and potentially life-saving updates on a cancer patient’s status.
Cancer Research UK, which funded the study, plan to expand this test to those who are at high risk of developing cancer, making early detection much more possible.
Michelle Mitchell, chief executive of the charity, said: “Liquid biopsies have the potential to revolutionise all aspects of cancer care, from early detection to personalised treatment and monitoring.
“As a field that relies heavily on technology, this kind of proof-of-concept research is incredibly important for us to invest in as a charity, as it’s what makes potential future leaps in the use of liquid biopsies possible, and ultimately save more lives.”
The research findings are published in the journal Science Translational Medicine.