NEW YORK (Reuters Health) – Daily low-dose aspirin reduces not only cardiovascular mortality but also nonvascular mortality – and cancer mortality in particular — after relatively short duration of treatment, according to the results of a meta-analysis published in the American Journal of Medicine online April 18.

“The impact of widespread aspirin use on cancer mortality may have a large and important impact on public health,” the authors comment. “The emerging evidence on aspirin’s cancer protection highlights an exciting time for cancer prevention through low-cost interventions.”

Dr. Edward J. Mills, at the University of Ottawa in Ontario, Canada, and colleagues point out that while low-dose aspirin is commonly prescribed for preventing cardiovascular disease, recent evidence indicates that various doses of aspirin have an anti-cancer effect.

To investigate the effect of daily low-dose aspirin, the team identified 23 relevant randomized trials that included data on nonvascular mortality; 11 of the studies also included information on cancer-specific mortality.

The pooled data indicated that during an average follow-up of 2.5 years there were 944 nonvascular deaths among 41,398 (2.28%) individuals in the aspirin groups and 1074 nonvascular deaths among 41,470 (2.58%) subjects not receiving aspirin. This difference was significant with a relative risk of 0.88.

Regarding cancer mortality, over an average follow-up of 2.8 years there were 162 cancer deaths among 7998 (2.02%) low-dose aspirin users and 210 among 8068 (2.60%) non-aspirin users—also a significant difference. The relative risk of cancer mortality was 0.77.

The treatment effect was apparent after about 4 years of follow-up, the authors report.

Dr. Mills and colleagues also note that they previously demonstrated a significant risk of major bleeding with low-dose aspirin, and they sound a note of caution in their summary despite the evidence of benefit in preventing nonvascular deaths.

“Public awareness of this may lead to widespread use of low-dose aspirin with or without clinician or pharmacist consultation,” they write. “Clinicians and pharmacists should be prepared to discuss the broad benefits and risks of aspirin beyond their traditional use in cardiovascular disease.”

SOURCE:

Am J Med 2012.