A single tablet of aspirin taken daily prevents the recurrence of polyps (growths) in patients who have already had bowel cancer, new research has shown.
The study of 720 patients in the US had to be prematurely stopped because the benefits of taking aspirin were so striking.
It found that 37 per cent fewer patients developed adenomas - a precursor to colon cancer - among those taking a standard daily dose of aspirin compared to patients who were given a placebo.
"While other research has shown that aspirin and other non-steroidal anti-inflammatory drugs may decrease the risk of colon cancer in large populations, this is the first to demonstrate in a scientific manner the protective properties of aspirin in people who have already had the disease", said Dr Electra Paskett, associate director of population sciences at the Ohio State University Comprehensive Cancer Centre.
The study findings, reported in today's edition of the US medical publication The New England Journal of Medicine, are based on a seven-year research project.
Participants were aged between 30 and 80, and all had been treated for colon or rectal cancer.
Researchers first screened the patients to ensure it was safe for them to take aspirin. Following an initial evaluation period, patients were randomly assigned to either the aspirin or the placebo group.
Taking 325mg of aspirin every day reduced the number of adenomas each patient developed, as well as prolonging the time it took them to develop.
Commenting on the research, Dr Padraig McMathúna, consultant gastroenterologist at the Mater hospital, said: "This clinical trial lends support to the role of aspirin in cancer recurrence."