Aspirin in the Chemoprevention of Colorectal Neoplasia: An Overview

reposted from: Cancer Prev Res (Phila). 2012 February; 5(2): 164–178.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273592/

crabsallover highlights, key points, comments / links.

Andrew T. Chan, Nadir Arber, John Burn, John Whay-Kuang Chia, Peter Elwood, Mark A. Hull,  Richard F. Logan, Peter M. Rothwell, Karsten Schrör, and John A. Baron

Abstract 

Considerable evidence supports the effectiveness of aspirin for chemoprevention of colorectal cancer (CRC) in addition to its well-established benefits in the prevention of vascular disease. Epidemiologic studies have consistently observed an inverse association between aspirin use and risk of CRC. A recent pooled analysis of a long-term post-trial follow-up of nearly 14,000 patients from 4 randomized, cardiovascular disease prevention trials showed that daily aspirin treatment for about 5 years was associated with a 34% reduction in 20-year CRC mortality. A separate meta-analysis of nearly 3,000 patients with a history of colorectal adenoma or cancer in 4 randomized adenoma prevention trials demonstrated that aspirin reduced the occurrence of advanced adenomas by 28% and any adenoma by 17%. Aspirin has also been shown to be beneficial in a clinical trial of patients with Lynch syndrome, a hereditary CRC syndrome; in those treated with aspirin for at least 2 years, there was a = 50% reduction in the risk of CRC commencing 5 years after randomization and after aspirin had been discontinued. A few observational studies have shown an increase in survival among patients with CRC who use aspirin. Taken together, these findings strengthen the case for consideration of long-term aspirin use in CRC prevention. Despite these compelling data, there is a lack of consensus about the balance of risks and benefits associated with long-term aspirin use, particularly in low-risk populations. The optimal dose to use for cancer prevention and the precise mechanism underlying aspirin’s anticancer effect require further investigation.

The mechanism of action of aspirin for chemoprevention

Possible sites of action of aspirin in the prevention of colorectal cancer. COX-dependent and independent targets of aspirin are likely to be present in both epithelial and stromal cell compartments in colorectal adenomas and cancers. ATLs, aspirin-triggered lipoxins; COX, cyclooxygenase; PGE₂, prostaglandin E₂; S-1P, sphingosine-1-phosphate.

Aspirin Foundation: Evidence for use of aspirin to prevent cancer - Prof Peter Elwood - Cardiff University, UK

Aspirin Foundation: Evidence for use of aspirin to prevent cancer - Prof Peter Elwood - Cardiff University, UK

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summarises the recent trials with aspirin and cancer.

reposted from: http://www.alphagalileo.org/ViewItem.aspx?ItemId=103955&CultureCode=en via Google 'aspirin', 'cancer' alert

crabsallover highlights, key points, comments / links.

Conference reviews cancer prevention benefits of prophylactic aspirin

24 May 2011 ecancermedicalscience

Recent evidence linking aspirin use with a reduced risk of several cancers could change the risk benefits analysis in favour of wider use of aspirin, concluded a meeting organized by the Aspirin Foundation. The report of the meeting “Aspirin, Salicylates and Cancer”, held November 2010 at the Royal Society of Medicine, has just been published in ecancermedicalscience. 

In the report Gareth Morgan, from Older People’s Services, NHS Wales, outlined the current evidence on aspirin and cancer prevention;  while Peter Rothwell, from Oxford University, explored the effects of aspirin on colon cancer risk; and Sir John Burn, from Newcastle University, looked at aspirin in the prevention and treatment of hereditary colorectal cancer.

Based its safety profile aspirin is the chemoprevention agent of choice in colorectal cancer, said Dion Morton from the University of Birmingham. The fact that aspirin reduces the risk of colorectal cancer with a latency of 10 years indicates that adenoma prevention, rather than down-staging cancer or preventing progression is probably the mechanism involved. He proposed a trial in which patients with high risk adenoma should be randomised to adjunctive treatment with aspirin or placebo.

Jack Cuzick, from Cancer Research UK, said that the cost of Phase II studies for early validation of the role of aspirin in cancer prevention could be minimised by the use of biomarkers and precursor lesions as end points.

Gordon McVie, from the European Institute of Oncology, Italy, said that several issues remain unresolved including the dose-response relationship in the prevention of colorectal cancer and the effect of enteric coating. The combinations of aspirin with other treatments, he added, was an avenue worth exploring in clinical trials.

Concluding the conference chairman, Peter Elwood, from the University of Cardiff, said that evidence of the risks and benefits of taking aspirin should be presented to the public in a package of measures to preserve health to allow them to make informed choices.

http://www.ecancermedicalscience.com/view-article.asp?doi=10.3332/ecancer.2011.213&type=abstract

download free conference report: http://www.ecancermedicalscience.com/cache/pdf/10.3332-ecancer.2011.213.pdf

• Full bibliographic informationG Morgan, P Rothwell, J Burn, A Chan, L Mur, D Morton, J Cuzick, G McVie, "Aspirin, Salicylates and Cancer: report of a meeting at the Royal Society of Medicine, London, 23 November 2010". E cancer 2011, 5:213 DOI: 10.3332/ecancer.2011.213.

Aspirin could cut cancer risk - The Independent video

reposted from: http://www.independent.co.uk/video/show/?play=/News/Aspirin_could_cut_cancer_risk

Take aspirin with a glass of milk says The Independent. Crabsallover thinks Prof. Peter Elwood recommends taking milk with aspirin. Milk is not mentioned in the Peter Rothwell December 7th Lancet paper.

Ed Yong of Cancer Research UK says see your GP before taking daily aspirin.

The research says low dose 75mg aspirin is as effective as larger 300mg doses which therefore cuts risks of bleeding and strokes.

start lobbying for popping a 75-milligram aspirin a day to be included as official cancer prevention lifestyle advice

reposted from:  http://www.guardian.co.uk/science/2010/dec/12/aspirin-cancer-wonder-drug-lancet
crabsallover highlights in red

Health reporting has its own lexicon of hyperbole. We get a dizzying number of apparent breakthroughs, advances that will revolutionise patients' lives and, of course, offer the Holy Grail – cures – far beyond the evidence. One national newspaper proclaims a new cancer cure on its front page on many Mondays. Only last week a procedure billed as a "cure" for Type 2 diabetes turned out, sadly, to be nothing of the sort.

And, of course, there are "wonder drugs", a description given to many of the cancer medications that NHS organisations have declined to give to patients because the National Institute of Health and Clinical Excellence has decided the potential benefit gained is less than the huge expense involved.

But aspirin, the humblest of medicines, surely merits that accolade after last week's research reported in The Lancet showing that regular small doses reduce the risk of many cancers, some by up to 54%. (We already knew that aspirin helps prevent heart attacks and strokes.)

Unlike most research findings, these ones could, and arguably should, lead many people – in this case the over-45s – to alter their behaviour. Not for nothing did BBC medical correspondent Fergus Walsh, 49, write in his blog: "From now on I am going to take a daily low-dose aspirin. I intend to continue doing this for the next 25 years."

Peter Elwood, honorary professor of epidemiology at Cardiff University, was part of a team of researchers who in 1974 provided the first real proof of aspirin's efficacy. "It's a miracle drug because it's a simple molecule that is unique in attacking both the world's two major causes of death and disability, cardiovascular disease and cancer." While some drugs – statins, for example – are good at preventing heart attacks and strokes, and some at tackling cancer, only aspirin does both, stresses Elwood.

One other advantage is its cheapness, itself a result of it being out of patent in most countries. Drug giant Bayer, its creator, makes little from it anymore. Aspirin is now a generic drug – anyone can make it. So are there any others like that? Sadly not. "No other out-of-patent drug offers anywhere like the same benefit," says Elwood.

Aspirin is the commonest of wonder drugs, available at corner shops, supermarkets and petrol stations for as little as a penny a tablet. It is usually used for headaches, hangovers, a migraine, angina or rheumatic pain, or to stop the blood clotting and so thwart a heart attack, stroke or blood clot.

But last week's findings did not convince everyone. "I wouldn't call aspirin a wonder drug," says Sultan "Sid" Dajani, a pharmacist and spokesman for the Royal Pharmaceutical Society, the professional body for the UK's 45,000 pharmacists.

"To me, a wonder drug brings maximum benefit and minimal risk. Statins and antibiotics are wonder drugs, because both save lives, and some anti-cancer drugs, such as Tamoxifen, Herceptin and Avastin, because, while toxic, they give you hope and maybe a second chance. And when the genetic medicines in development become available – the 'magic bullet' drugs that can switch off genes that are precursors to things like diabetes, cancer and osteoporosis – if they work, they'll clearly be wonder drugs. But not aspirin."

For him, the risk of aspirin causing a stomach bleed is too great. Another drug, Clopidogrel, is more effective than aspirin and carries less risk, he says, but it's prescription-only and is far less available on the NHS because it costs much more than little white aspirin tablets. 

Elwood points out that while heart attacks and stroke have a 40% death rate, the worst outcome from excess consumption of aspirin is bleeding that will require a blood transfusion. "Compare the seriousness involved," he pleads.

After last week's breakthrough, some of the UK's most senior doctors will start lobbying for popping a 75-milligram aspirin a day to be included as official cancer prevention lifestyle advice, alongside not smoking, being physically active and eating healthily. Don't be surprised if they succeed.

• by Denis Campbell Health Correspondent
• The Observer, Sunday 12 December 2010