Giving cancer patients aspirin at the same time as immunotherapy could dramatically boost the effectiveness of the treatment, according to new research published in the journal Cell by a team from the Francis Crick Institute.
Funded by Cancer Research UK, the researchers have shown that aspirin, as part of a group of molecules called COX inhibitors, stops the production of PGE2 (prostaglandin E2) which is produced in large amounts by skin, breast and bowel cancer cells. PGE2 helps cancer to effectively hide, and dampen down the immune’s system normal response to faulty cells.
In testing, combining immunotherapy with aspirin or other COX inhibitors substantially slowed bowel and melanoma skin cancer growth in mice, compared to immunotherapy alone.
Study author, Professor Caetano Reis e Sousa, senior group leader at the Francis Crick Institute, commented: “We’ve added to the growing evidence that some cancers produce PGE2 as a way of escaping the immune system. 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.
“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 more effective, delivering life-changing results for patients.”
Professor Peter Johnson, Cancer Research UK’s chief clinician, said: “PGE2 acts on many different cells in our body, and this study suggests that one of these actions is to tell our immune system to ignore cancer cells. Once you stop the cancer cells from producing it, the immune system switches back to “kill mode” and attacks the tumour.
“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.”