Daily low-dose aspirin 'reduces death rates for several cancers'
A new study in the Lancet medical journal adds to a growing body of evidence suggesting that a daily dose of aspirin can reduce the risk of dying from several types of cancer, with even low-dose aspirin appearing to be beneficial.
Scientists from the University of Oxford and the London School of Hygiene and Tropical Medicine have reviewed eight clinical trials involving more than 25,500 patients, all of which were designed to investigate the effect of long-term aspirin on the heart and blood vessels.
When data from these randomised trials were combined, the results showed that taking aspirin was associated with a 21 per cent lower risk of dying from cancer.
Overall, death rates for all cancers fell by 34 per cent after five years of aspirin use, and those for cancers of the digestive system dropped by 54 per cent.
As well as looking at the five-year risk of dying from cancer, the researchers were able to analyse data for 20 years after the trials had ended.
During this period, there were 1,634 deaths from cancer, but the researchers found that patients who had previously taken aspirin had a 20 per cent lower risk of dying from solid cancers than those who had not, and a 35 per cent lower risk of dying from cancers of the digestive system.
The new study is the latest to show that the drug can help to prevent deaths from a range of common cancers. It follows a previous paper in the October issue of the Lancet showing that long-term low-dose aspirin reduced death rates from bowel cancer by more than a third.
The benefits were strongest for bowel, oesophageal and stomach cancers. Aspirin could also help to prevent deaths from pancreatic, lung and brain cancers.
The researchers believe that patients may gain the most benefit by starting to take aspirin in their late 40s or 50s, when the risk of developing many cancers begins to rise.
They also say that such an intervention would be cost-effective, even if patients have to be given other medicines alongside aspirin to reduce the risk of bleeding complications.
Professor Peter Rothwell, from the University of Oxford and the city's John Radcliffe Hospital, said: "These results do not mean that all adults should immediately start taking aspirin, but they do demonstrate major new benefits that have not previously been factored into guideline recommendations.
"Previous guidelines have rightly cautioned that in healthy middle-aged people, the small risk of bleeding on aspirin partly offsets the benefit from prevention of strokes and heart attacks, but the reductions in deaths due to several common cancers will now alter this balance for many people."
Professor Rothwell emphasised that more research is needed, including studies to determine the effects of aspirin on cancer incidence and breast cancer, and longer follow-up studies.
He concluded: "Perhaps the most important finding for the longer term is the proof of principle that cancers can be prevented by simple compounds like aspirin and that 'chemoprevention' is therefore a realistic goal for future research with other compounds."
Ed Yong, head of health information and evidence at Cancer Research UK, said: "These promising results build on a large body of evidence suggesting that aspirin could reduce the risk of developing or dying from many different types of cancer. While earlier studies suggested that you only get benefits from taking high doses of aspirin, this new study tells us that even small doses reduce the risk of dying from cancer, provided it is taken for at least five years.
"In addition to the effect on cancer death, aspirin can affect our health in other ways, such as reducing the risk of stroke but increasing the chances of bleeding from the gut. We await trial results expected next year to learn more about these different effects."
He added: "We encourage anyone interested in taking aspirin on a regular basis to talk to their GP first."
- Rothwell et al. 2010. Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials. Lancet DOI: 10.1016/S0140-6736(10)62110-1