Personalised cancer blood test hope
Personalised blood tests which could track whether cancer treatment is working or if the disease has come back have been developed by US researchers.
The test identifies tumour DNA "rearrangements" which are specific to the individual patient.
In the future, this "genetic fingerprint" could be used to pick out tiny remnants of a tumour, Science Translational Medicine reports.
Such techniques are currently very expensive but costs are falling.
The researchers hope that one day the technology could be used to spot cancer recurrence before they would be picked up by scans.
DNA from volunteer patients was scanned for rearrangements of large chunks of genetic information which occur in cancer cells but not normal cells.