These 'sleeper cells', which do not typically show up on scans, can be found in patients' bone marrow and are a key factor in cancer returning.
In the trial, specific drugs successfully cleared these cells from 80 per cent of 51 breast cancer survivors, with only two patients experiencing recurrence after six to twelve months of treatment.
Researchers found that the drugs effective against these dormant cells differ from those used for actively growing cancers, indicating a distinct biological mechanism.
This development offers significant hope for breast cancer survivors, as recurrent breast cancer has previously been considered incurable.