Wonder pill aspirin may prevent cancer

If it was developed today, the century-old drug might struggle to get through clinical trials because it can cause major damage to the lining of the stomach along with severe internal bleeding.

But a major study published yesterday gave yet another reason to keep making aspirin, which is also used to treat strokes and cataracts and boost the chances of having a baby while undergoing IVF treatment.

Researchers at Massachusetts General Hospital and Brigham and Women's Hospital in Boston studied more than 80,000 female nurses who took part in a major health study for more than 20 years.

They found that taking aspirin at least twice a day for more than ten years lowered the risk of getting colon cancer by 53 per cent, according to a report in the Journal of the American Medical Association. Taking a lower dose of between one and two pills a day resulted in a 22 per cent lower risk.

However the researchers estimated that for every one or two cases of cancer prevented by taking high doses of aspirin, about eight people would develop serious gastro-intestinal bleeding.

Dr Andrew Chan, of Massachusetts General Hospital, who was the lead author of the scientific paper on the study, said: "Our study did find a protective effect of long-term aspirin use on risk of invasive colorectal cancer, but only at dosage levels considerably higher than those used to prevent cardiovascular disease." Heart disease patients tend to take "baby" aspirin, which is one-quarter of the dose of full-strength aspirin, daily.

Previous research has linked aspirin with preventing the recurrence of colon cancer, but this is the first time it has been shown to reduce the risk of getting the disease in the first place and what strength of dose is required to have a significant effect.

"Several earlier studies have found that, among patients with a history of colon polyps or cancer, regular aspirin treatment prevents the recurrence of precancerous polyps," Dr Chan said.

"However, the ability of aspirin to reduce the long-term incidence of invasive cancer has not been well-demonstrated."

He told The Scotsman that further work was continuing to develop a new form of aspirin that did not have such severe side-effects.

"There may be some clinical applications down the road," Dr Chan said. "I don't think we can currently recommend people take aspirin, especially at this high dose. There may be particular people who have an especially high risk of getting colorectal cancer for whom it may be worth taking, but that sort of treatment needs to be discussed carefully with a doctor."

Out of the 83,000 people included in the nurses health survey, there were 962 cases of colorectal cancer diagnosed over a 20-year period.

Derek Napier, chief executive of the St Andrews-based Association for International Cancer Research, said doctors and patients would have to balance the relative risks.

"If aspirin has a significant effect in lowering the chance of getting colorectal cancer, it may well be people who are at risk of that may feel the possibility of side-effects is worth the risk," he said.

Ed Yong, Cancer Research UK's science information officer, said more work was needed to "weigh up all of the risks and benefits" of high doses of aspirin before recommendations can be made.

And Mr Yong pointed out: "Besides taking aspirin, there are many other ways of reducing the risk of bowel cancer such as keeping a healthy bodyweight, being active and eating lots of fibre and fish and less red or processed meat."

A 5,000-YEAR-OLD WONDER DRUG

ASPIRIN has been used in one form or another for some 5,000 years.

In about 3,000BC, Egyptians used myrtle leaves and willow - both of which contain salicylic acid, the main ingredient in aspirin - to relieve muscle pain.

In 1763, the Rev Edward Stone, of Oxfordshire, carried out trials of willow bark extract on people suffering from a fever and found it helped them.

Aspirin was patented in 1898 by Felix Hoffman, a German working for Bayer, the pharmaceutical company, and he is credited with its invention two years earlier.

However, some claim it was actually invented by Hoffman's boss, Arthur Eichengrun, but that this was written out of history by the Nazis because Eichengrun was Jewish.

A landmark study in the 1980s showed the drug produced a major reduction in the risk of having a heart attack.

Aspirin is also used to treat strokes, cataracts and blindness. Some studies have shown it can double the chances of an IVF pregnancy and delay the onset of senility, while its blood-thinning properties also mean it can be used to prevent deep-vein thromboses.

Today, about 100 billion aspirins are taken every year throughout the world.