Long-term aspirin use protects against bowel cancer in people with Lynch syndrome – a genetic disorder that predisposes to the disease – according to research partly funded by Cancer Research UK.
The study is the first randomised controlled trial to look at aspirin’s effect on cancer incidence, and according to the authors, the case for using aspirin to prevent cancer in patients with Lynch syndrome is now clear.
The trial followed nearly 1,000 patients with Lynch Syndrome, an inherited genetic disorder associated with an increased risk of several cancers, especially bowel cancer. Around 1 in 30 bowel cancer cases are associated with the condition, also known as hereditary non-polyposis colon cancer (HNPCC), which is carried by around one person in every thousand.
People with Lynch syndrome are about 10 times more likely that the general population to develop cancer, particularly of the bowel and womb, and often at a young age.
The study, published in The Lancet, involved 43 centres in 16 countries. Some of the patient’s progress was followed for more than 10 years.
In the trial, 861 patients started either to take two aspirins (600 mg) each day (434 patients) or a placebo (427) for at least two years. There was no change in bowel cancer incidence between the two groups in the first analysis in 2007.
But the protective effects of aspirin became clear over time: by 2010 there were 34 new cases of the condition among those who took the placebo, compared with 19 among people who took aspirin – a 44 per cent reduction in incidence.
More analysis, this time of patients who took aspirin for at least two years (60 per cent of the total), saw an even more pronounced effect of the drug. There was a 63 per cent reduced incidence of bowel cancer in these long-term users, with 23 cancers in the placebo group and just 10 in the aspirin group.
Taking all cancers linked to Lynch syndrome into account, nearly 30 per cent of people taking a placebo developed a cancer compared with around 15 per cent of those taking the aspirin. There was no difference in side-effects between aspirin and placebo groups.
According to the authors: “Our results, taken in conjunction with recent research, provide a basis for recommendation of aspirin chemoprevention in Lynch Syndrome as standard of care.”
Study leader Professor John Burn from Newcastle University, said: “We have succeeded in showing the benefits of aspirin because we had a lot of long term data and because Lynch Syndrome is associated with rapid development of cancer.”
Professor Chris Paraskeva, Cancer Research UK’s bowel cancer expert at the University of Bristol, said: “This is a really important study showing that aspirin can significantly reduce the risk of bowel and other cancers in patients genetically at high risk of developing cancer.
“This adds to the growing body of evidence showing the importance of aspirin, and aspirin-like drugs, in the fight against cancer and emphasises how critical it is to carry out long term international research.”
David Willetts MP, Minister for Universities and Science, said: “This groundbreaking study is an excellent achievement for the UK research base and a welcome addition to our robust body of evidence on cancer.
“It has the potential to save thousands of lives worldwide and is clear evidence of the value of long-term studies showing simple steps that can be taken to improve people’s lives.”
Copyright Press Association 2011
- Burn, J, et al. Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial. Lancet doi:10.1016/S0140-6736(11)61049-0