Monday, 30 January 2012

Take aspirin daily - even for those at low cardiovascular risk

reposted from:
crabsallover highlightskey pointscomments / links.

The Lancet, Volume 377, Issue 9778, Page 1651, 14 May 2011
doi:10.1016/S0140-6736(11)60669-7Cite or Link Using DOI

Aspirin in the prevention of cancer

That aspirin can help to prevent cancer1 has caught the public's attention. How does this benefit compare with the rather modest benefit in lessening cardiovascular events previously reported in those at low cardiovascular risk? In a previous study of such patients,2 the prevention was only three events in women and four in men among 1000 people studied over 6·4 years. The cost was 2·5 major bleeds per 1000 per 5 years in women and three in men, so the overall benefit was truly modest. By contrast, the cancer prevention rates in the study by Rothwell and colleagues1 included 15 gastrointestinal cancer deaths per 1000 people over 5 years. These benefits vastly outweighed the risk of major bleeds.
In view of these new facts, we should no longer be reserved about recommending aspirin even for those at low cardiovascular risk. However, we are still lacking firm data on when aspirin should be started in those at low risk, and at which dose. The doses of aspirin protecting from cancer in Peter Rothwell and colleagues' study1 were in the range of 75—300 mg daily. My guess is to start at a low dose—say 75 mg—in the early 50s.
I delare that I have no conflicts of interest.


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 Berger JSRoncaglioni MCAvanzini FPangrazzi ITognoni GBrown DLAspirin for the primary prevention of cardiovascular events in women and men: a sex-specific meta-analysis of randomized controlled trialsJAMA 2006295306-313CrossRef |PubMed
a Hatter Cardiovascular Research Institute, University of Cape Town Medical School, Observatory, Cape Town 7925, South Africa

We agree with L H Opie that, in individuals without previous vascular events, both the relative and absolute reductions in risk of death due to cancer on aspirin versus control are larger than the equivalent reductions in risk of fatal vascular events, and that effects on cancer outcomes will dominate the overall risk/benefit equation, particularly when the delayed effects on cancer death beyond the end of the trials is also factored in.

No comments: