Daily aspirin use for at least 5 years reduced cancer deaths by 21% (OR 0.79) compared to control, though its use for primary prevention must be balanced against increased bleeding risks.
Does aspirin reduce cancer mortality and cardiovascular events in the general population for primary prevention?
While aspirin shows potential for reducing long-term cancer mortality, its use for primary prevention must be carefully weighed against the increased risk of significant gastrointestinal and intracranial bleeding.
Effect estimate: OR 0.79 (95% CI 0.68 to 0.92)
Aspirin was discovered in 1897 and marketed initially as an analgesic. Over the years it has been used for other purposes including the prevention of both arterial and venous thrombosis, and as an anti-inflammatory drug. More recently there has been interest in the use of aspirin for primary and secondary prevention of cancer. A recent study published in the Lancet,1 showing impressive benefits of low dose aspirin in reducing both cancer mortality and all-cause mortality, received a lot of press publicity. The Daily Mail for example, claimed ‘Aspirin really can beat cancer’.2 No doubt following this publicity many primary care doctors have been asked the question ‘Doctor, should I be taking aspirin?’. In this article we discuss how this latest publication fits in with previous evidence, and the clinical implications of the findings in relation to the primary prevention of cancer. Many studies have investigated the benefits of aspirin in relation to cardiovascular disease. A recent meta-analysis of aspirin and heart disease by the Antithrombotic Triallists’ Collaboration (ATTC) has quantified these benefits.3 This large study reported an analysis of individual patient data from trials of both primary prevention (95 000 subjects) and secondary prevention (17 000 subjects). In trials of primary prevention the aspirin dose varied between 75 mg and 500 mg. There was no significant reduction in cardiovascular mortality and a small reduction in cardiovascular events. We have calculated the number needed to treat (NNT) to prevent one cardiovascular event with aspirin treatment for 1 year was 1666. Benefits for secondary prevention were more impressive with both reduction in cardiovascular events (NNT = 66 with treatment by aspirin for 1 year) and deaths (NNT = 344 with treatment by aspirin for 1 year). This study confirmed the importance of aspirin in secondary prevention of cardiovascular disease, …
Rose et al. (Mon,) conducted a review in Cancer and cardiovascular disease. Aspirin vs. Control was evaluated on Cancer deaths after 5 years of follow-up (OR 0.79, 95% CI 0.68 to 0.92). Daily aspirin use for at least 5 years reduced cancer deaths by 21% (OR 0.79) compared to control, though its use for primary prevention must be balanced against increased bleeding risks.