Researchers Claim Aspirin Reduces Risk Of Colon Cancer
October 28, 2011

Researchers Claim Aspirin Reduces Risk Of Colon Cancer

New research from the British universities Newcastle and Leeds suggest that taking two aspirin a day for two years reduces the long-term risk of hereditary colon cancer by as much as 60 percent in those people with a family history of the disease. 

The findings of the study, published in The Lancet, could have implications for the wider population, though more research is needed to determine an ideal dosage for different groups of people.

Scientists described the results as “the icing on the cake” after more than 20 years of research into aspirin´s effect on cancer.

However, in recent years there has been a lot of debate about the benefits of taking aspirin routinely, which increases the risk of stomach ulcers and internal bleeding. But studies have also confirmed aspirin´s role in protecting against heart problems.

This new study specifically looks at the preventative effect aspirin has on people with a hereditary condition known as Lynch Syndrome, thought to affect about 60,000 people in Britain, and responsible for one in 30 cancers of the bowel.

Bowel cancer is the third most common cancer in Britain, with 40,000 new cases annually and over 16,000 deaths.

The study, led by Professor Sir John Burns of Newcastle University, followed 861 middle-aged people with Lynch Syndrome. They found that those who took two 300mg aspirin pills daily for two years, were 63 percent less likely to have developed bowel cancer five years later, than those who were given a placebo.

The results are critical for those with the Lynch Syndrome because their lifetime risk of developing colon cancer is as high as one in two.

Tim Bishop, one of the authors of the study and a professor of epidemiology at Leeds University in England, told Nanci Hellmich of USA TODAY the new findings provide “one more piece of evidence that there are some very positive effects of aspirin, and it should be considered very seriously for people who are at risk of colorectal cancer.”

Burn said he was “very pleased” with the “impressive” results. He and Bishop suggested those with the syndrome should start taking aspirin from the age of 20, as they run the risk of developing cancer well before middle age.

“If we were to put them on aspirin now, we would stop about 10,000 cancers over 30 years,” said Burn. However, only 1 in 10 of those with Lynch Syndrome know they even have it.

This study reinforces a breakthrough study last year led by Professor Peter Rothwell of Oxford University that found people taking low dose aspirin daily for five years were 25 percent less likely to have developed bowel cancer after 20 years than those not taking it.

Other observational studies have shown that aspirin lowers the risk of developing colon cancer, but Burn and Bishop´s study is the first randomized controlled trial to find the effect.

“We have clear proof that aspirin prevents cancer in people at high genetic risk. We now have new questions to answer: Will low dose be as effective as two aspirins? Should all people at increased risk take aspirin?” Burn told USA TODAY.

Bishop says researchers don´t know for sure how aspirin works to prevent cancer, “but one speculation is that the active part of aspirin causes DNA-damaged cells to die.”

“There are certainly lots of benefits of taking aspirin,” Bishop told Hellmich. “But people have to weigh the tradeoffs. With larger doses of aspirin comes the increase danger of ulcers and vascular bleeds.”

The study, funded in part by Bayer, also found some evidence of a reduction in other solid cancers linked to Lynch Syndrome.

“This is a really important study showing that aspirin can significantly reduce the risk of bowel and other cancers in patients genetically at high risk of developing cancer,” Chris Paraskeva of the University of Bristol, who was not involved in the research, told Reuters.

Andrew Chan of Harvard Medical and Scott Lippman of the MD Anderson Cancer Center in Houston said in a commentary in The Lancet that the findings were “compelling” and arguably supported more general recommendations to consider aspirin for preventing bowel cancer, based on individual patients´ risks.

Burn and Bishop now aim to determine the best dose for those with Lynch Syndrome and want to recruit 3,000 people around the world to participate. The duo said subjects would most likely be given either 600, 300 or 75mg pills daily.

David Willetts, the Universities and Science Minister, said the study is “an excellent achievement for the UK research base.”

“It has the potential to save thousands of lives worldwide and is clear evidence of the value of long-term studies showing simple steps that can be taken to improve people´s lives,” Willetts told The Telegraph.

Eric Jacobs, an epidemiologist with the American Cancer Society, said in statement that “there is good evidence that long-term regular aspirin use can also modestly reduce risk of colorectal cancer in people who do not have Lynch syndrome.”

“However, aspirin use is not currently recommended specifically for cancer prevention because even low-dose aspirin can increase risk of serious stomach bleeding,” he said, adding that aspirin use should be discussed with a healthcare provider before taking on such a regimen.

There are many ways to help prevent colorectal cancer, Jacobs adds. “All people 50 or older should get tested for colon cancer, so that precancerous polyps can be found and removed before they ever turn into cancer. In addition, maintaining a healthy weight, being physically active, not smoking and eating less red meat can help lower risk of colorectal cancer.”

The National Health Service (NHS) is on track to deal with a 45 percent increase in cancer cases by 2030, Cancer Research UK has warned. It predicts the number will climb from 298,000 in 2007 to 432,000 by 2030, which could “overwhelm NHS resources.

The biggest reason for such an increase is the ageing population. But lifestyle changes are also a factor. Cancers of the mouth, kidney and liver are forecast to be among the biggest risers, due in part to smoking and drinking.


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