Cancer treatments could be more effective when they are combined with aspirin, a British study has suggested.
The anti-inflammatory pain killer was found to suppress a cancer molecule that allows tumours to evade the body's immune defences.
Experts said the research findings were "exciting" and suggested that drugs which cost just a few dollars could make "a huge difference".
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 showed that skin, breast and bowel cancer cells often generated large amounts of a molecule called prostaglandin E2 (PGE2).
The study found that aspirin and other members of the "Cox inhibitor" drug family block its production, leaving tumours exposed to attack.