Evidence mounts that Aspirin can help prevent cancer

by Bruce Sylvester – taken from The Lancet –

A study by Professor Peter M Rothwell, University of Oxford, UK and colleagues supports the hypothesis and adds to the evidence that daily aspirin helps prevent  cancer.

The study was published on March 20, 2012 in the Lancet.

The researchers retrospectively evaluated patient data from 51 randomized trials of daily aspirin versus no aspirin, trials testing for prevention of vascular events such as heart attacks.

They found that aspirin reduced the risk of a cancer death by 15% compared with controls. And there was a 37% reduced risk of a cancer death for subjects on aspirin for 5 years or longer.

Aspirin-related reduction in cancer deaths resulted in a 12% reduction in non-vascular deaths overall during the trials.

In these trials of primary prevention, the reduction in non-vascular deaths accounted for almost all (91%) of the deaths prevented. Daily low-dose aspirin reduced cancer incidence by around a quarter from 3 years and onwards, with similar reductions in men (23%) and women (25%).

Notably, the reduced risk of major vascular events was initially offset by an increased risk of major bleeding. But both effects diminished over time, leaving the reduced risk of cancer from 3 years and onwards (an absolute reduction of 3 cases per 1000 patients per year, 12 per 1000 control versus 9 per 1000 in aspirin groups).

Case-fatality from major extracranial bleeds was also two thirds lower among aspirin users compared to controls.

The authors said, “Alongside the previously reported reduction by aspirin of the long-term risk of cancer death, the short-term reductions in cancer incidence and mortality and the decrease in risk of major extracranial bleeds with extended use, and their low case-fatality, add to the case for daily aspirin in prevention of cancer.”

They added, “In view of the very low rates of vascular events in recent and ongoing trials of aspirin in primary prevention, prevention of cancer could become the main justification for aspirin use in this setting.”