A DAILY dose of aspirin can slash the risk of developing bowel cancer by 60 per cent.
A ground-breaking trial has proved that taking two of the “wonder” pills a day gives long-term protection and could save thousands of lives each year.
Lead researcher Professor Sir John Burn, of the University of Newcastle, said: “We have finally shown that aspirin has a major preventative effect on cancer, but this doesn’t become apparent until years later.
“If you gave two aspirin a day for two years to people with hereditary bowel cancer, after five years their cancer risk will be reduced by more than half.”
The landmark British study was hailed by Professor Nick Hastie, director of the Medical Research Council Human Genetics Unit, as providing “the clearest evidence yet” that aspirin can protect against cancer.
He said: “As we learn more about the underlying mechanism of this effect, we will eventually be able to develop new ways of preventing and treating cancer.”
The study was carried out in patients at high risk of bowel cancer but experts hope the findings could have wider implications in the general population.
There was also evidence of a similar impact on cancers with the same genetic link – womb, ovarian, pancreatic, brain, stomach and kidney.
Further research is to be carried out, but the researchers said people with a family history of bowel cancer may want to start taking a low dose of aspirin as a preventative measure after first discussing it with their doctor.
The study, called CAPP2 and published online in The Lancet, provides the most definitive evidence yet of aspirin’s anti-cancer properties.
It focused on patients with Lynch syndrome, a genetic fault that strongly predisposes people to bowel cancer.
Around one in 1,000 of the population carry the genes, which account for one in 30 cases of bowel cancer.
Those affected are 10 times more likely than average to develop cancer.
Each year around 40,000 people in Britain are diagnosed with bowel cancer and more than 16,000 die from it.
The findings suggest aspirin treatment could prevent up to 10,000 cancers over the next 30 years and possibly save 1,000 lives. Despite taking large doses of aspirin – two 300 milligram pills per day – patients suffered no adverse effects.
Aspirin is known to raise the risk of strokes, internal bleeding and stomach ulcers, so there is a trade-off.
It is given to people at risk of heart attacks or stroke. As a long-term anticoagulant or a preventative measure for heart disease, the dose is 75mg a day. As a painkiller, the recommended dose is 275 to 300mg, not exceeding three doses a day.
A new investigation will look at the dose needed to prevent cancer.
The CAPP2 study between 1999 and 2005 involved 861 people identified as Lynch syndrome carriers and given aspirin or a placebo.
Results in 2007 showed no difference in bowel cancer rates. But by 2010 there was a 44 per cent reduced incidence rate linked to the aspirins.
Further analysis of the 60 per cent who took aspirin for at least two years revealed a 63 per cent difference.
Professor Chris Paraskeva, Cancer Research UK’s bowel cancer expert, said: “This adds to the growing body of evidence showing the importance of aspirin in the fight against cancer.”
Mark Flannagan, chief executive of Beating Bowel Cancer, said: “These results are really very promising.”