A combination of immunotherapy and a virus could treat aggressive breast cancer, an 'absolutely amazing' study has revealed.
Breakthrough research showed the pairing cured up to 90 per cent of mice plagued by triple negative breast cancer - deemed the deadliest form.
Canadian scientists are hopeful the findings will lead to a potential cure, as survival depends on how early the disease is caught.
The trial, led by Ottawa University scientists, comes as a separate study found that an injection of a virus could also treat aggressive brain tumours.
Breakthrough research showed the pairing cured up to 90 per cent of mice plagued by triple negative breast cancer - deemed the deadliest form
Dr Marie-Claude Bourgeois-Daigneault, lead author of the Canadian study, was full of praise for the findings, which may apply to humans.
She said: 'It was absolutely amazing to see that we could cure cancer in most of our mice, even in models that are normally very resistant to immunotherapy.
'We believe that the same mechanisms are at work in human cancers, but further research is needed to test this kind of therapy in humans.'
Every year 11,400 people die from breast cancer in the UK. In the US, the figure is around four times higher.
Charities estimate around 15 per cent of all cases of breast cancer are triple negative - but death rates are proportionally higher.
The study, published in Science Translational Medicine, adds to the growing body of evidence that shows the vast benefits of immunotherapy.
All of the mice in the study were resistant to the checkpoint inhibitor, which blocks proteins on cancer cells to stop them from growing, that was used.
Immunotherapy, described as 'game changing', is hailed as the biggest advance in cancer treatment in decades.
It is considered far kinder than chemotherapy, which can cause pain and loss of appetite by targeting healthy and diseased cells.
Instead, immunotherapy 'turbo-charges' the immune system so it targets and kills just cancer cells. It's usually given in weekly infusions.
The treatment has already proven hugely effective against some deadly cancers, extending the lives of terminal patients by up to five years.
Despite the array of research, the drugs were rejected for NHS funding in April before health chiefs back tracked in the autumn.
They vowed in September to fund the drug