New study looking at risks and benefits of daily aspirin

A number of news outlets recently reported on a new study which has looked at the benefits and risks of taking daily aspirin for individuals without a history of heart disease.

The study pooled data from a number of previous, large clinical trials which have looked at this. The results suggested that aspirin can prevent heart attacks and strokes in these individuals. However, a known but rare side effect of aspirin is internal bleeding. As has been seen in other studies, this research confirmed that those individuals who were taking aspirin in the trials were more likely to suffer serious bleeding, though the risk of bleeding for any individual was small.

These trials were not designed to look at whether aspirin can prevent cancer. In this pooled study, the researchers found no indication that aspirin had an effect on cancer incidence, but the data to assess this may have been limited and further information is needed – for example, about the different types of cancer occurring during the trials, and whether the study participants had had a previous cancer diagnosis.

Participants in the Add-Aspirin trial have had treatment for a previous cancer - we expect any benefits of aspirin (in terms of cancer prevention) to be greatest in these individuals, because of the risk of the cancer returning. This has not yet been confirmed and will be looked at in the trial. As such, we do not believe the results of this recent study changes the Add-Aspirin trial. Individuals who have an increased risk of internal bleeding are not eligible for the Add-Aspirin trial, and participants and data from the trial are monitored closely in relation to this.