Aspirin could help boost cancer treatment, experts find

'Exciting' study results show anti-inflammatory pain killer suppresses cancer molecule that allows tumours to evade body's immune defences

By Laura Donnelly, Health Editor

5:00PM BST 03 Sep 2015

Cancer treatment could be more effective when it is combined with aspirin, new research suggests.

The anti-inflammatory pain killer suppresses a cancer molecule that allows tumours to evade the body's immune defences, a study has found.

Experts said the research findings were “exciting”, suggesting that drugs that cost just a few pence could make “a huge difference” helping to save lives.

But they cautioned that the findings would need to be confirmed by further trials before aspirin was routinely given as part of cancer treatment.

Laboratory tests show that skin, breast and bowel cancer cells often generate large amounts of a molecule called prostaglandin E2 (PGE2).

The study found aspirin and other members of the "Cox inhibitor" drug family block its production so that tumours have nowhere to hide. In mice, combining immunotherapy with drugs such as aspirin substantially slowed the growth of bowel and malignant skin cancer.

Professor Caetano Reis e Sousa, who led the team from the Francis Crick Institute in London, said: "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 even more effective, delivering life-changing results for patients."

The ability of cancers to manufacture PGE2 may be one reason why some experimental immunotherapy treatments have not lived up to expectations.

Professor Peter Johnson, chief clinician at Cancer Research UK, which funded the study published in the journal Cell, 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."