Aspirin and cancer prevention

When Eichengrün and colleagues at dye manufacturer Friedrich Bayer & Co synthesised acetylsalicylic acid in 1897 the success story of aspirin began,1 and its potential applications are still being revealed. It is well established that aspirin reduces pain, limits the inflammatory response, and reduces cardiovascular disease but that it can lead to major bleeding events and gastrointestinal upset. For several years increasing numbers of studies have suggested a benefit of aspirin on the occurrence of polyps and colorectal cancer.2 3 Potential beneficial effects on other common cancer types have also been reported.4 Two recently published large scale studies have provided additional evidence that low dose aspirin reduces the incidence of cancer, death from cancer, and cancer metastasis.5 6

The first, an analysis of the short term effects of daily aspirin (<300 mg) use on various cancer related outcomes in 51 randomised controlled trials,5 found that allocation to aspirin reduced deaths from cancer (odds ratio 0.85, 95% confidence interval 0.76 to 0.96), particularly from five years of daily use onwards, resulting in fewer deaths from …