Routine aspirin ‘a step closer’
Experts say that routine use of aspirin for primary prevention of cancer has moved a step closer with the publication of data showing it reduces short-term cancer incidence and mortality - and may even treat existing cancers.
Having previously demonstrated that daily aspirin reduces 20-year cancer mortality, Professor Peter Rothwell (University of Oxford, UK) and colleagues now report that it reduces cancer incidence by one quarter after just 3 years, and cancer deaths by 37% from 5 years onwards.
The team also noted an even earlier reduction in cancer deaths in high-dose aspirin trials, suggesting the drug had prevented growth of clinically occult cancers already present at the beginning of the studies. Moreover, a separate analysis showed that aspirin reduced the risk of cancer with distant metastasis by 36%. The researchers say these findings suggest that aspirin's impact on cancer mortality is due at least partly to metastasis prevention - and that it may be effective in the treatment of some cancers.
Rothwell and team report these latest findings in two papers published in the Lancet. In a third paper, published in the Lancet Oncology, they also report findings from observational data that is consistent with randomised trial results in showing that aspirin reduces the risk of colorectal cancer, as well as of oesophageal, gastric, biliary and breast cancer.
In an accompanying editorial, Professors Andrew Chan and Nancy Cook, from Harvard Medical School in Boston, Massachusetts, USA, say it is still too soon to recommend routine use of aspirin at the population level, given that these data come from vascular disease prevention trials. Studies including cancer as a prespecified endpoint (and therefore less open to bias) have found no cancer benefit with alternate-day aspirin up to 10-12 years.
Furthermore, they say that bleeding remains a concern when weighing up the benefits and risks of aspirin. Nonetheless, they conclude, the current evidence "moves us another step closer to broadening recommendations for aspirin use".
GP News is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Caroline Price