An Irish-funded study has found that women who have been prescribed aspirin regularly, before being diagnosed with breast cancer, are less likely to have cancer that spreads, than women not on prescription aspirin.
The study examined data from more than 2,700 women with various stages of breast cancer.
It found that aspirin may reduce death from breast cancer by preventing the cancer spreading to the lymph nodes.
The link was strongest among women prescribed aspirin regularly and women prescribed higher aspirin doses.
Professor Kathleen Bennett, co-author from the Department of Pharmacology & Therapeutics at Trinity College Dublin, said the results do not mean that women should start taking aspirin as a precautionary measure.
She said that aspirin can have serious side effects and studies are needed to identify exactly how aspirin may prevent cancer from spreading, which women or types of breast cancer would most likely benefit from taking aspirin and the optimum doses.
The research was funded by the Health Research Board and the Irish Cancer Society and is published in Cancer Journal by the American Association for Cancer Research.
Research to answer the outstanding questions is being funded by the Irish Cancer Society.