Monday, 30 January 2012

Risk of GI bleed with Aspirin

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The Lancet, Volume 377, Issue 9778, Pages 1650 - 1651, 14 May 2011
doi:10.1016/S0140-6736(11)60668-5Cite or Link Using DOI

Aspirin in the prevention of cancer

Although Peter Rothwell and colleagues1 provide the strongest evidence to date for the effect of aspirin in cancer prevention, they do not consider the well known adverse effects of aspirin, and focused on one potential benefit of aspirin in a study largely confined to middle-aged men.
Risk and benefit increase with age.2 Although the results look impressive when presented in proportional reduction terms, they are less so in “real” terms (14 000 people took aspirin for at least 4 years for a saving of about 100 cancer deaths). It is important, therefore, to be aware that a small proportion of those who develop serious adverse events, such as haemorrhagic stroke and major gastrointestinal bleeding, could reduce or reverse the benefit.2—4
In older people, for whom serious adverse events are much more common and their consequences potentially more serious, the risk/benefit equation will probably be different. The ASPirin in Reducing Events in the Elderly (ASPREE) trial5 examines whether the benefits of daily aspirin outweigh the risks in people aged 70 years or older. The ASPREE primary endpoint is extension of life free from dementia and disability. The trial will be able to show the true overall benefit of routine use of aspirin in older people for primary prevention beyond simply counting individual adverse events.
I have received travel support from Bayer Healthcare—a manufacturer of aspirin. This company is also providing aspirin for ASPREE, of which I am a principal investigator.


1 Rothwell PMFowkes FGBelch JFOgawa HWarlow CPMeade TWEffect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trialsLancet 201137731-41Summary | Full Text | PDF(502KB) |CrossRef | PubMed
2 Hernandez-Diaz SRodriguez LAIncidence of serious upper gastrointestinal bleeding/perforation in the general population: review of epidemiologic studiesJ Clin Epidemiol 200255157-163CrossRef | PubMed
3 He JWhelton PKVu BKlag MJAspirin and risk of hemorrhagic stroke: a meta-analysis of randomized controlled trials.JAMA 19982801930-1935CrossRef | PubMed
4 Pirmohamed MJames SMeakin S, et alAdverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patientsBMJ 200432915-19CrossRef | PubMed
5 Nelson MRReid CMAmes D, et alFeasibility of conducting a primary prevention trial of low-dose aspirin for major adverse events in the elderly in Australia: ASPirin in Reducing Events in the Elderly (ASPREE)Med J Aust 2008189105-109PubMed
a Menzies Research Institute/University of Tasmania, Private Bag 23, Hobart, Tasmania 7001, Australia

Mark Nelson raises the issue of the risk of bleeding on aspirin. We deliberately made no specific recommendations about the widespread use of aspirin in healthy individuals, but we did discuss the issue of bleeding in some detail. Our analyses showed that taking aspirin daily for 5—10 years would reduce all-cause mortality (including any fatal bleeds) during that time by about 10% in relative terms. Subsequently, there would be further delayed reductions in risk of cancer death even if aspirin was stopped.
In healthy middle-aged individuals, the risk of major bleeding on aspirin is relatively low (about 0·2 per 1000 patients per year—only a small proportion of which are fatal),3 and is already offset in many groups by the small reduction in risk of ischaemic vascular events.3 The reduction in risk of cancer is therefore additional to this existing balance in which the bleeding risk is already taken into account. However, the risk of bleeding on aspirin increases steeply with age and so we did not comment on use of aspirin in healthy individuals older than 75 years. The results of the ASPREE trial will be of great importance in this respect.
3 Antithrombotic Trialists' (ATT) CollaborationAspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trialsLancet 20093731849-1860Summary | Full Text | PDF(329KB) CrossRef | PubMed

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