A small daily dose of aspirin - 75mg - substantially reduces death rates from a range of common cancers, a study suggests.
Research at Oxford University and other centres found that it cut overall cancer deaths by at least a fifth.
Those patients who were given aspirin had a 25% lower risk of death from cancer during the trial period and a 10% reduction in death from any cause compared to patients who were not given the drug.
The risk of cancer death was reduced by 20% over 20 years. For individual cancers the reduction was about 40% for bowel cancer, 30% for lung cancer, 10% for prostate cancer and 60% for oesophageal cancer.
The reductions in pancreas, stomach and brain cancers were difficult to quantify because of smaller numbers of deaths.
There was also not enough data to show an effect on breast or ovarian cancer and the authors suggest this is because there were not enough women on the trials. Large-scale studies investigating the effects on these cancers are under way.
Professor Rothwell said he was not urging healthy middle-aged adults to immediately start taking aspirin, but said the evidence on cancer "tips things towards it being well worth it". The benefit in cancer reduction were found from a low daily dose of 75mg.
