Low aspirin dose lowers cancer risk in Lynch syndrome

A daily low dose of aspirin is as effective as higher doses in reducing cancer risk for people with Lynch syndrome, according to new research.

Lynch syndrome is an inherited condition caused by a faulty gene, which significantly increases the risk of cancers such as bowel and womb cancer. In the study, 1,879 people with the condition were given daily doses of either 100mg, 300mg or 600mg of aspirin.

Researchers from Newcastle University found that the smallest dose – 100mg – offered the same level of protection as the larger ones, with a reduced chance of side effects. The UK standard for a low dose is 75mg, sometimes referred to as “baby aspirin”. Based on the findings, researchers are now recommending this lower 75mg dose.

The study, known as Cancer Prevention Project 3 (CaPP3), was funded by Cancer Research UK and ran for nearly a decade.

Professor Sir John Burn, who led the international trial, said he would be asking health regulators to recommend a daily 75mg dose for people with Lynch syndrome.

He said: “We already have NICE guidance saying people with Lynch syndrome should be recommended to take aspirin. Now we should recommend a baby aspirin.

“So what we can now say with statistical confidence is that the people taking a baby aspirin are as protected as the people taking two aspirins – but also much less likely to have side effects.”

A previous study, also led by Prof Burn, showed a protective benefit in those taking 600mg of aspirin daily for just over two years. The latest findings confirm the lower dose is just as effective.

Burn said: “Roughly speaking, if someone with Lynch syndrome has about a 2 per cent a year chance of getting mostly bowel cancers, we think if they take aspirin, that is halved – down to about 1 per cent a year.”

Nick James, a furniture maker from Newcastle, was the first person to join the trial, nearly ten years ago. He has Lynch syndrome and has lost nearly all of his family in the UK to cancer.

Wanting to reduce his own risk, he signed up for the study without knowing which dose he was receiving. He later learned he had been taking the 300mg dose.

He said: “Quite a few members of my family have had cancer – like colorectal cancers, or endometrial.

“My grandfather had bladder cancer, my mum had a certain kind of cancer. When you start looking at the family tree – it becomes quite apparent what’s going on.

“We didn’t actually know it was Lynch syndrome until 13 years ago, and that’s when I learned about the aspirin trials.”

He described the findings as “massively reassuring” for him and his family.

He said: “The fact that I can now go down to a baby aspirin makes it feel less scary.

“I didn’t have any major side effects – but it potentially reduces any.

“That the research has shown that taking an aspirin reduces your risk of getting a cancer if you have Lynch syndrome is massively reassuring for me – and my family.”

Aspirin can sometimes cause internal bleeding, which is why the researchers aimed to determine the lowest effective dose.