More evidence that blood samples could help monitor breast cancer
"There is some way to go before this could be developed into a test that doctors could use routinely, and doing so is never simple” - Professor Jacqui Shaw, Cancer Research UK
The discovery could also be used to make earlier predictions about whether a woman’s breast cancer will return following treatment, according to the scientists.
Using specialised DNA-reading technology, the researchers were able to track key genetic faults in circulating tumour DNA isolated from patients’ blood samples.
While still under development, the approach – published in the journal Science Translational Medicine – could offer an alternative to more invasive biopsy procedures.
The hope is that this method could lead to a test that identifies and helps track the genetic faults within a patient’s tumour, possibly months in advance of conventional approaches.
But such a test is a long way off, according to Professor Jacqui Shaw, an expert in circulating tumour DNA from Cancer Research UK, which part-funded the study.
“This important study suggests that looking for tumour DNA in a patient’s blood after they’ve been treated for early stage breast cancer could help monitor them, and even make predictions about whether their disease may come back,” she said.
“And it may be possible to do this before tumours become visible on conventional scans. But there is some way to go before this could be developed into a test that doctors could use routinely, and doing so is never simple.”
The researchers, based at the Institute of Cancer Research, London (ICR), and the Royal Marsden NHS Foundation Trust, analysed tumour and blood samples from 55 breast cancer patients.
All patients were in the early stages of the disease and had received chemotherapy followed by surgery. Blood samples were taken after surgery and then every six months in follow-up.
The researchers found that women who tested positive for circulating tumour DNA were 12 times more likely to see their breast cancer come back, compared to those who tested negative.
And for those who did see their cancer come back, the DNA analysis was able to detect this nearly eight months before any visible signs emerged.
The findings build on previous research that first highlighted the potential of using tumour DNA from blood samples to help monitor breast cancer. And further research has shown how this could detect the earliest stages of tumours that may have spread – potentially months before they are visible on scans.
And according to Professor Shaw, this latest study reinforces the potential of using blood samples as a kinder way of monitoring a patient’s cancer.
“Finding less invasive ways of diagnosing and monitoring cancer is really important. And fishing for fragments of tumour DNA, or even rogue cancer cells, released into the bloodstream has emerged as a hugely promising way to do this,” she said.
Professor Paul Workman, Chief Executive of the ICR, said the study was part of a new era of research on ways of monitoring how tumours develop and change over time.
“It is really fantastic that we can get such a comprehensive insight about what is going on in the cancer all over the body, without the need for invasive biopsies,” he said.
“Studies like this also give us a better understanding of how cancer changes to evade treatments – knowledge we can use when we are designing the new cancer drugs of the future.”
The study was funded by the NIHR Biomedical Research Centre at The Royal Marsden and the ICR, Breast Cancer Now and Cancer Research UK.