title: Estimates of benefits and harms of prophylactic use of aspirin in the general population.
abstract: BACKGROUND
  Accumulating evidence supports an effect of aspirin in reducing overall cancer incidence and mortality in the general population. We reviewed current data and assessed the benefits and harms of prophylactic use of aspirin in the general population.
  
  
  METHODS
  The effect of aspirin for site-specific cancer incidence and mortality, cardiovascular events was collated from the most recent systematic reviews. Studies identified through systematic Medline search provided data regarding harmful effects of aspirin and baseline rates of harms like gastrointestinal bleeding and peptic ulcer.
  
  
  RESULTS
  The effects of aspirin on cancer are not apparent until at least 3 years after the start of use, and some benefits are sustained for several years after cessation in long-term users. No differences between low and standard doses of aspirin are observed, but there were no direct comparisons. Higher doses do not appear to confer additional benefit but increase toxicities. Excess bleeding is the most important harm associated with aspirin use, and its risk and fatality rate increases with age. For average-risk individuals aged 50-65 years taking aspirin for 10 years, there would be a relative reduction of between 7% (women) and 9% (men) in the number of cancer, myocardial infarction or stroke events over a 15-year period and an overall 4% relative reduction in all deaths over a 20-year period.
  
  
  CONCLUSIONS
  Prophylactic aspirin use for a minimum of 5 years at doses between 75 and 325 mg/day appears to have favourable benefit-harm profile; longer use is likely to have greater benefits. Further research is needed to determine the optimum dose and duration of use, to identify individuals at increased risk of bleeding, and to test effectiveness of Helicobacter pylori screening-eradication before starting aspirin prophylaxis.
authors.affiliation: Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK. Electronic address: j.cuzick@qmul.ac.uk.
authors.forename: J
authors.initials: J
authors.lastname: Cuzick
authors.affiliation: Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Thorat
authors.affiliation: Department of Epidemiology, IRCCS-Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Bosetti
authors.affiliation: Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Brown
authors.affiliation: Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: J
authors.initials: J
authors.lastname: Burn
authors.affiliation: Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston.
authors.forename: N R
authors.initials: NR
authors.lastname: Cook
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda.
authors.forename: L G
authors.initials: LG
authors.lastname: Ford
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Jacobs
authors.affiliation: Centre for Biomedical Research-Translational and Stratified Medicine, Peninsula Schools of Medicine and Dentistry, Plymouth University, Plymouth; Centre for Digestive Diseases, Blizard Institute of Cell and Molecular Science, Queen Mary University of London, London, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Jankowski
authors.affiliation: Department of Epidemiology, IRCCS-Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Law
authors.affiliation: Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, USA.
authors.forename: F
authors.initials: F
authors.lastname: Meyskens
authors.affiliation: Stroke Prevention Research Unit, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Rothwell
authors.affiliation: Tumor and Breast Center ZeTuP, St Gallen, Switzerland.
authors.forename: H J
authors.initials: HJ
authors.lastname: Senn
authors.affiliation: Gastrointestinal and Other Cancers Research Group, Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda, USA.
authors.forename: A
authors.initials: A
authors.lastname: Umar
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000627:therapeutic use; D001241:Aspirin / Q000009:adverse effects* / Q000627:therapeutic use*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000517:prevention & control*; D009369:Neoplasms / Q000517:prevention & control*; D020521:Stroke / Q000517:prevention & control*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin
keywords: aspirin; benefit-harm; cancer; cardiovascular disease; gastrointestinal bleeding; prevention
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