Aspirin could be combined with immuno-oncology treatments to boost their cancer-killing power, according to a new study.

The research, conducted by the Francis Crick Institute and funded by Cancer Research UK, demonstrated that cancer cells often produce large amounts of prostaglandin E2 (PGE2), a molecule that dampens the immune system’s normal response to attack faulty cells. CRUK says that this may explain why some immunotherapies have not been as effective as hoped.

COX inhibitors like aspirin inhibit the production of PGE2 and helps reawaken the immune system – and the researchers found that combining the common painkiller with immunotherapy ‘substantially’ slowed bowel and melanoma skin cancer growth in mice compared to immunotherapy alone.

“It’s still early work but this could help make cancer immunotherapy even more effective, delivering life-changing results for patients,” says study author professor Caetano Reis e Sousa, senior group leader at the Francis Crick Institute.

Professor Peter Johnson, Cancer Research UK’s chief clinician, adds: “This research was carried out in mice so there is still some way to go before we will see patients being given COX inhibitors as part of their treatment. But it’s an exciting finding that could offer a simple way to dramatically improve the response to treatment in a range of cancers.”

Aspirin’s interactions with cancer is an increasingly exciting area of research. One study last year suggested that a daily dose of the drug could significantly cut the risk of developing and dying from a number of cancers in the digestive tract.