Destroying ‘sleeper cells’ may be the key to ensuring breast cancer never comes back.
New research could pave the way to ensure any and all cancer cells are made dormant for longer or possibly even killed entirely.
Around 30 per cent of breast cancer patients taking hormone therapies see their cancer eventually return – sometimes as long as 20 years after treatment.
The returning cancer has usually spread around the body and tumours are often resistant to medication.
Study lead author Dr Luca Magnani, of Imperial College, London, said: “For a long time scientists have debated whether hormone therapies – which are a very effective treatment and save millions of lives – work by killing breast cancer cells or whether the drugs flip them into a dormant ‘sleeper’ state.
“This is an important question as hormone treatments are used on the majority of breast cancers.
“Our findings suggest the drugs may actually kill some cells and switch others into this sleeper state.
“If we can unlock the secrets of these dormant cells, we may be able to find a way of preventing cancer coming back, either by holding the cells in permanent sleep mode, or be waking them up and killing them.”
The Imperial team studied around 50,000 human breast cancer single cells in the lab, and found that treating them with hormone treatment exposed a small proportion of them as being in a dormant state.
The study, funded by Cancer Research UK and the NIHR Imperial Research Centre, was published in the journal National Communications.
Dr Rachel Shaw, of Cancer Research UK, said: “Although treatments for breast cancer are usually successful, cancer returns for some women, often bringing with it a poorer prognosis.
“Figuring out why breast cancer sometimes comes back is essential to help us develop better treatments and prevent this from happening.”
She added: “This study highlights a key route researchers can now explore to tackle ‘sleeping’ cancer cells that can wake up years after treatment, which could potentially save the lives of many more women with the disease.”
