A pioneering new type of immunotherapy has seen a woman with late-stage, terminal breast cancer apparently completely cured of the condition.
Judy Perkins from Florida had advanced cancer that had failed to respond to traditional treatments and had spread to secondary locations in the body, including her liver, where tennis ball-sized tumours were present.
She had been planning her death, but two years after she received immunotherapy, there is no sign of any cancer anywhere in her body.
The treatment involved screening the patient's white blood cells and extracting those that were capable of attacking the cancer. They were identified as cells that had invaded the tumour in an attempt to kill it by targeting its mutations, but were too weak to do so.
Next, these cells were replicated in their billions in a laboratory and screened again to check which would be capable of finding and destroying cancer cells by recognising abnormal proteins.
Finally, 90 billion of the new immune cells were injected back into the patient to act as a living drug made from her own immune cells.
Incredibly, in what is believed to be the first successful application of T-cell immunotherapy for late-stage breast cancer, the woman appears to have been cured.
The research was carried out at the US National Cancer Institute and published in the journal Nature Medicine.
Lead author Dr Steven Rosenberg told BBC News: "We're talking about the most highly personalised treatment imaginable. It remains experimental and still requires considerably more testing before it can be used more widely, but this is how it works: it starts by getting to know the enemy."
So far, this type of adoptive cell transfer has proved effective on skin cancer but not other forms of the disease. However, it is hoped that this new success could mark a turning point in immunotherapy because it responds to individual mutations as opposed to cancer type.
There are currently around 11,400 breast cancer deaths in the UK every year and it is the fourth most common cause of cancer death in Britain, according to Cancer Research.