An aspirin a day could prevent bowel cancer, study shows
Thursday 26 June 2025
An aspirin a day can prevent bowel cancer in people at high risk of the disease, a major clinical trial has confirmed.
The CaPP3 trial, led by Newcastle University and funded by Cancer Research UK, has found that taking a low daily dose of 75 –100mg of aspirin reduces the risk of bowel cancer in people with Lynch syndrome.
While higher doses of aspirin have previously been shown to prevent bowel cancer, this new trial of almost 1,900 people has found that a lower daily dose works just as well in cutting this risk, potentially allowing more patients to benefit.
Updating advice for GPs
The National Institute of Health and Care Excellence (NICE) currently recommends that people with Lynch syndrome consider taking aspirin daily to prevent bowel cancer.
However, a 2016 survey revealed that less than half of GPs were aware that they should recommend aspirin to people with Lynch syndrome, while many were worried about the high recommended dose of 600mg.
Scientists leading the research are now in talks with the British National Formulary to update the advice it gives on aspirin when used as a cancer prevention drug. This would make it easier for GPs to prescribe aspirin to those patients.
‘This is a big moment in cancer research’
Dr Lisa Wilde, Director of Research, Policy and Influencing at Bowel Cancer UK, said: “We’ve known for some time that aspirin reduces the risk of bowel cancer for people with Lynch syndrome, but we haven’t known how large a dose is needed of the drug to get this benefit safely.
“We’re delighted that the CaPP3 trial has found that lower doses of aspirin are just as effective in reducing the risk of bowel cancer. This could help more people with Lynch syndrome get the benefits of taking aspirin, while reducing the likelihood of experiencing the side effects associated with higher doses.
“We now call on health authorities across the UK to update formularies and national guidelines to reflect these results and encourage more doctors to prescribe aspirin for people with Lynch syndrome.
“This is a big moment in cancer research, and potentially a major milestone in cancer prevention. We look forward to seeing how the results of this trial could prevent more people from developing bowel cancer and ultimately save more lives.”
- Learn more about this trial and what it means for those with Lynch syndrome
- Find out more about our campaign on Lynch syndrome
- Learn more about aspirin
