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Tuesday 7 June 2011

Lancet Correspondence on Peter Rothwell studies on Aspirin & Cancer, 14 May 2011

This is an important series of 4 letters published May 2011 about Peter Rothwells work on Aspirin and Cancer followed by a comment by Peter Rothwell.

reposted from: http://download.thelancet.com/pdfs/journals/lancet/PIIS0140673611606661.pdf
and Peter Rothwells comments: http://download.thelancet.com/pdfs/journals/lancet/PIIS0140673611606703.pdf?id=e16241398b8eb460:3c68b886:1306b6f6506:38b41307479634423

crabsallover highlightskey pointscomments / links.

The new data on cancer help to clarify the net benefit of aspirin, particularly if aspirin were included with a statin and bloodpressure- lowering drugs in a combined formulation (Polypill). Aspirin causes substantially fewer major extracranial bleeds that require a blood transfusion than the number of CVD events and cancer deaths prevented (table).




Aspirin in the prevention of cancer, N J Wald, J K Morris, M R Law
Peter Rothwell and colleagues, in their meta-analysis of randomised trials (Jan 1, p 31),1 show that low-dose long-term aspirin use reduces the risk of several cancers. Before this information was available, the balance of benefit and harm in taking aspirin in the primary prevention of coronary heart disease and stroke (cardiovascular disease [CVD]) was uncertain. The new data on cancer help to clarify the net benefit of aspirin, particularly if aspirin were included with a statin and bloodpressure- lowering drugs in a combined formulation (Polypill). 


The table shows the estimated number of first CVD events and cancer deaths prevented in England and Wales in 1 year on the basis of a Polypill (composed of three blood-pressure lowering drugs at half standard dose and a statin at standard dose such as simvastatin 40 mg), with or without aspirin. 


In people aged 55–89 years, for example, 186 000 CVD events and cancer deaths would be prevented. The table shows that 120 such outcomes would be prevented in 1000 people over a period of 20 years (or 170 per 1000 over 35 years).2–6 


Aspirin causes substantially fewer major extracranial bleeds that require a blood transfusion than the number of CVD events and cancer deaths prevented (table). However, the risk of an aspirin-induced major extracranial bleed increases with age.4 


The estimates for such bleeds shown in the table among people aged 55 years over a period of 20 years are based on observed data and are likely to be accurate, but the numbers in people older than 75 years are uncertain— they would be twice those shown if the age trend to 75 years continues to 90 years. 


Given the results published by Rothwell and colleagues,1 the balance of the evidence is in favour of including aspirin in a Polypill strategy to prevent CVD and cancer.


NW and ML hold a European and Canadian patent (pend ing in the USA) for the Polypill, filed in April 2000.


 *N J Wald, J K Morris, M R Law n.j.wald@qmul.ac.uk Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK 
1 Rothwell PM, Fowkes FG, Belch JF, Ogawa H, Warlow CP, Meade TW. Eff ect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials. Lancet 2011; 377: 31–41. 
2 Law M, Wald N, Morris J. Lowering blood pressure to prevent myocardial infarction and stroke: a new preventive strategy. Health Technol Assess 2003; 7: 31. 
3 Offi ce for National Statistics. Mortality statistics: deaths registered in 2009. London: Stationery Offi ce, 2010. http://www.statistics.gov.uk/ downloads/theme_health/dr2009/dr-09.pdf (accessed April 27, 2011). 
4 Antithrombotic Trialists’ (ATT) Collaboration. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet 2009; 373: 1849–60. 
5 Law MR, Wald NJ, Rudnicka AR. Quantifying the eff ect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis. BMJ 2003; 326: 1423–27. 
6 Wald NJ, Law MR. A strategy to reduce cardiovascular disease by more than 80%. BMJ 2003; 326: 1419–23.


Author’s reply 
We agree with N J Wald and colleagues that our results and their analyses do suggest that aspirin should be included in Polypill regimens, although the balance of risk and benefit is less certain in older individuals owing to the increase in risk of bleeding with age.

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