Further research suggests aspirin can reduce risk of breast cancer

A new piece of research has provided further evidence to suggest that individuals who take aspirin have a lower risk of developing breast cancer. Researchers collected information from 57,000 female teachers in California over a period of more than 15 years.

In keeping with previous studies, the researchers found that women who took low dose aspirin (normally defined as 75mg – 100mg) were less likely to develop breast cancer. In particular, they were less likely to develop a common type of breast cancer known as a hormone receptor positive/HER-2 negative cancer.  The findings were reported in the journal Breast Cancer Research and also in the news media  . Previous studies have reported similar findings but some of those studies did not have information about aspirin dose or types of breast cancer. These findings need confirming.

There are some important limitations to this type of study – in particular, there are many other factors that will affect an individual’s risk of developing cancer, and these may differ for those people who did take aspirin and those who did not. 

Participants in the Add-Aspirin trial will have had a previous diagnosis and treatment for cancer, and so their risk of cancer returning will be higher than in the general population and they may derive an even greater benefit from taking aspirin. We do not believe that this new information affects the rationale for the trial but we will continue to monitor all new information carefully.