Giving cancer patients aspirin at the same time as immunotherapy could dramatically boost the effectiveness of the treatment, according to a new research on mice.
Researchers from the Francis Crick Institute have shown that skin, breast and bowel cancer cells often produce large amounts of prostaglandin E2 (PGE2).
This molecule dampens down the immune system’s normal response to attack faulty cells, which helps cancer to hide. It is a trick that allows the tumour to thrive and may explain why some immunotherapy treatments have not been as effective as hoped.
Aspirin is part of a group of molecules called COX inhibitors, which stop the production of PGE2 and help reawaken the immune system.
Combining immunotherapy with aspirin or other COX inhibitors substantially slowed bowel and melanoma skin cancer growth in mice, compared to immunotherapy alone, researchers said.
The type of immunotherapy tested was anti-PD-1.
“We’ve added to the growing evidence that some cancers produce PGE2 as a way of escaping the immune system,” said study author Professor Caetano Reis e Sousa, senior group leader at the Francis Crick Institute.
“If you can take away cancer cells’ ability to make PGE2 you effectively lift this protective barrier and unleash the full power of the immune system,” Sousa said.
“Giving patients COX inhibitors like aspirin at the same time as immunotherapy could potentially make a huge difference to the benefit they get from treatment.
“It’s still early work but this could help make cancer immunotherapy even more effective, delivering life-changing results for patients,” Sousa said.
“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,” said Professor Peter Johnson, chief clinician at Cancer Research UK, which funded the study.
“But it’s an exciting finding that could offer a simple way to dramatically improve the response to treatment in a range of cancers,” he said.
The research was published in the journal Cell.