Men can reduce their risk of prostate cancer by almost a third with a daily dose of aspirin, research has revealed.
The new research highlights the theory that inflammation plays a vital role in the disease.
The effects of anti-inflammatory drugs, such as aspirin, on men with prostate cancer were studied by American scientists who looked at 1,000 sufferers and a similar number of healthy people.
They found that daily use of low-dose aspirin lowered the risk of being diagnosed with prostate cancer by 29%.
Long-term aspirin use for more than five years was associated with a 24% reduced risk. However, no protection was seen from other non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.
The findings are reported in the American Journal of Epidemiology.
In their conclusions, the scientists, led by Dr Janet Stanford, from the Fred Hutchinson Cancer Research Centre in Seattle, Washington, wrote: "The significant inverse association between prostate cancer risk and use of aspirin that we observed provides additional support for the role of inflammation in the development of this cancer.
"Aspirin is a widely used and inexpensive medication, and the potential public health implications of an effective chemopreventive agent for prostate cancer are considerable."
Each year around 35,000 men in the UK are diagnosed with prostate cancer, and some 10,000 die from the disease.
The Prostate Cancer Charity said the results of the study should be treated with caution, and warned healthy men not to start dosing themselves with aspirin.