Aspirin a day cuts cancer risk after just three years
People can significantly reduce their chances of being diagnosed with cancer by taking an aspirin a day for as little as three years, according to new research.The cheap drug not only appears to stop cancers developing in the first place, but also prevents them from spreading to other parts of the body, the new work shows.
Those who start taking low dose (75mg) aspirin daily in their 60s appear to benefit just as much as those who start taking it earlier.
The study Effect of daily aspirin on risk of cancer metastasis published in The Lancet, add to the argument that low dose aspirin should be taken widely from middle-age, said the lead author, Professor Peter Rothwell, of Oxford University’s Stroke Prevention Research Unit.
His team found that taking low dose daily aspirin for between three and five years reduced the chance of being diagnosed with cancer at that time by 19 per cent. Five years or more after starting taking aspirin, the reduction rose to 30 per cent.
He said: “These data do push the argument in favour of taking daily low-dose aspirin, particularly if you have a family history of heart disease or cancer.
“We showed previously that daily aspirin substantially reduces the long-term risk of some cancers, particularly colorectal cancer and oesophageal cancer, but that these effects don’t appear until about eight to 10 years after starting treatment.
“The delay is because aspirin is preventing the very early development of cancers and there is a long delay between this early stage and the eventual clinical presentation with a cancer.
“What we have now shown is that aspirin also has short-term effects, which are manifest after only two to three years.”
The effect was just as marked in those who started taking it after they had turned 60.
The short-term effect appeared to be caused by aspirin slowing the progression of cancer. Another new study showed aspirin almost halved the chances of diagnosed cancer spreading to other organs, over 6.5 years.
Prof Rothwell said: “This is important because it is this process of spread of cancer, or ‘metastasis’, which most commonly kills people with cancer.”
After five years, the chance of having died from cancer if on aspirin was 37 per cent lower.
The findings also raised “the distinct possibility that aspirin will be effective as an additional treatment for cancer – to prevent distant spread of the disease”, he said.
Aspirin has long been hailed for its blood-thinning properties, leading some to argue that it should be prescribed to those who are at a higher risk of heart attack or stroke, even if they have never had one.
However, researchers have been increasingly worried that the benefits of reduced heart attacks and strokes are cancelled out by the raised risk of stomach bleeds, which are occasionally fatal.
But Prof Rothwell said the new research showed that aspirin had a far greater effect on reducing cancer than reducing heart attacks and strokes. Nine out of 10 deaths it prevented were “non-vascular”, according to one of the studies.
Critics of widespread aspirin use point out that it triggers stomach bleeding in some people, which can occasionally be fatal. Even advocates concede it should be used with caution in over 75s.
Prof Rothwell said their studies showed that while aspiring doubled the risk of bleeds in the first three years, after that the risk fell so there was no difference to not taking it. Aspirin also did not increase the risk of fatal bleeds, he said.