A new method of analysing cancer patients’ blood for evidence of the disease could be up to 10 times more sensitive than previous methods, according to new research.
In the coming years, this method, and others based on this approach, could lead to tests that more accurately determine if a patient is likely to relapse after having treatment and could pave the way for the development of pinprick home blood tests to monitor patients.
The technique uses personalised genetic testing of a patient’s tumour to search blood samples for hundreds of different genetic mutations in circulating tumour DNA (ctDNA), DNA released by cancer cells into the bloodstream.
Combined with new methods to analyse this data to remove background noise and enhance the signal, the team was able to reach a level of sensitivity that in some cases could find one mutant DNA molecule among a million pieces of DNA – about 10 times more sensitive than previous methods.
Dr Nitzan Rosenfeld, senior group leader at the Cancer Research UK Cambridge Institute, who led the team at the University of Cambridge that conducted this research, said: “Personalised tests that can detect if cancer is still present, or find it early if it is returning, are now being tested in clinical trials.
“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.”
