A drug traditionally used to treat lung and ovarian cancer is set to undergo trials for its effectiveness in preventing hereditary breast cancer.
The international clinical trial, run by London-based researchers, will test the impact of carboplatin on women with a strong history of the cancer in the family.
It is thought that around five per cent of breast cancer sufferers have a history of the illness in their family and that over 75 per cent of these families have poorly-formed BRCA1 or BRCA2 genes.
Carboplatin is believed to concentrate on these particular faulty genes, which give carriers an 85 per cent risk of developing the disease by the time they reach 70.
Dr James Mackay, a genetic oncologist at University College London and co-leader of the study, said: "This trial is unique because it is the first to treat a specific genetic population of breast cancer patients.
"Because this is an established drug which is routinely used for the treatment of ovarian cancer, it has moved swiftly into trials and could be available to patients within five years if it proves to be effective."
The drug, which is thought to be 20 times more effective at killing cancer cells than chemotherapy, could be available within five years.