Drugs commonly used to treat arthritis could help prevent the spread of breast cancer.
Researchers found three NHS arthritis drugs had the potential to stop the disease reaching a patient’s bones, where it becomes incurable.
The discovery means anakinra, canakinumab and sulfasalazine could be used to treat breast cancer once more testing has been done.
Scientists found bone marrow releases a protein called interleukin 1-beta that helps cancerous cells grow and make secondary tumours in bones which cannot be treated.
The team from the University of Manchester and University of Sheffield found the three drugs blocked that process.
Following treatment with anakinra, only 14% of mice in the study developed secondary tumours in the bone, compared to 42% of control animals.
More research is needed to understand how these drugs may interact with the immune system and other cancer therapies.
Lead author Dr Rachel Eyre, of the University of Manchester, said: “We will now look to see if similar processes are also involved in breast cancer growing in other organs, such as the liver and lungs.
“We hope we could in future identify those at high risk of their breast cancer spreading, and where possible use drugs already available to prevent this from happening.”
Breast Cancer Now, which largely funded the study, said around 55,000 women and 370 men are diagnosed with breast cancer each year, making it the UK’s most common cancer.
It kills about 11,500 women a year, almost all from tumours that have spread to other parts of the body.
It most commonly spreads to the bones, brain, lungs or liver.
Chief executive Baroness Delyth Morgan said: ““While more research is needed, it’s really exciting that these well-tolerated and widely-available arthritis drugs may help prevent secondary breast cancer in the bone."
