Low-dose aspirin slashes colon cancer risk - study
Saturday 23 October 2010
Low doses of aspirin, taken daily and over the long term, cut cases of colorectal cancer by a quarter and the death toll from this disease by a third, according to a study published online on Friday by The Lancet.
Aspirin is already recommended in low, daily doses by many doctors for patients at risk of a heart attack or a stroke.
High doses of this cheap, over-the-counter medication have similarly been found to help prevent cancer of the rectum and colon.
But, studies have also found, the benefits may well be outweighed by the risks, such as increased bleeding from high aspirin use.
Eager to verify whether low doses can also be protective, researchers followed up four trials in Britain and Sweden, conducted in the 1980s or early 1990s, on the cardiovascular impacts of aspirin.
The study entailed looking over centralised data banks to see whether volunteers in these trials had since died or been diagnosed with colorectal cancer.
On average, the trials lasted six years, entailing volunteers who took either aspirin or a dummy lookalike pill called a placebo. The doses ranged up to 1,200 mg.
Out of 14,033 patients whose health could be traced 18 years or so since the trial, 391 had colorectal cancer, the investigators found.
Taking aspirin reduced the risk of cancer by 24 percent and the risk of dying from it by 35 percent.
The results were consistent across all four trials - and there was no increase in benefits beyond a dose of 75 mg.
Where the reduction was most remarkable was in cases of proximal colon cancer.
These occur in the upper colon and are thus liable to be missed in lower-intestine scans for polyps, the precursor of tumours.
The authors say their study had limits, as the original trials were not designed to look at aspects of colorectal cancer, nor was data available for any deaths from aspirin's side effects.
Also, aspirin's benefit may have been somewhat over-estimated, they said.
This was because the original trials took place before colon screening for polyps became a routine practice in those countries.
Even so, the evidence has now swung the scales in favour of low-dosage aspirin for a disease that claims 600,000 deaths worldwide each year, they said.
"Our findings suggest that long-term low-dose aspirin treatment and sigmoidoscopy screening would combine to substantially reduce cancer incidence in all parts of the colon and rectum," said the lead author, Peter Rothwell, a professor at the Department of Clinical Neurology at Oxford University.
In a commentary, doctors Robert Benamouzig and Bernard Uzzan of the Avicenne Hospital in Bobigny, on the outskirts of Paris, said the study should unleash "the next logical step," of formulating guidelines for people at risk.
Colorectal cancer is the second commonest cancer in developed countries, with a lifetime risk of five percent, according to figures cited in the city.
Aspirin is believed to have a preventive effect because it inhibits an enzyme called COX-2, which promomotes cell proliferation in colorectal tumours.
Jennifer Lawrence attacks mass media again over body image
Paris charity auction staged to save the ancient city of Tyre
scienceScientists find the answer to a question that even puzzled Darwin
A very timely Great Train Robbery and a frantic 24 Hours in A&E among the highlights
arts + entsThe 'Friends' actor on his new role as campaigner on addiction issues
Life & Style blogs
The 10 Best Scotch Whiskies
America's 'virgin births'? One in 200 mothers 'became pregnant without having sex'
Last orders looming for Trappist beers as Belgium's band of brotherly brewers dies off
Facebook 'self-censorship': study records when you don't post to find more ways to share
Vitamin pills are a waste of money, offer no health benefits and could be harmful - study
- 1 America's 'virgin births'? One in 200 mothers 'became pregnant without having sex'
- 2 Sun will 'flip upside down' within weeks, says Nasa
- 3 Christmas comes early: Justin Bieber announces he's 'retiring from music'
- 4 Children evacuated from swimming pool after prosthetic leg mistaken for paedophile
- 5 Status: Wet - Woman walks off a pier while checking Facebook on her phone
- < Previous
- Next >
£60000 - £80000 per annum: Pro-Recruitment Group: Have you been waiting for th...
£22000 per annum: Inspiring Interns: This fast-growing multinational company h...
£25000 - £28000 Per Annum: Clearwater People Solutions Ltd: 2nd Line Support T...
Negotiable: Capita Education Resourcing Permanent Team: Primary Year 1 Teacher...