Aspirin may halve the risk of death from breast cancer in women who have had early treatment for the disease, researchers have found.
The effect was revealed in an analysis of data from the US Nurses' Health Study, which followed 238,000 nurses in the US for more than 30 years. It is the first time aspirin has been shown to significantly reduce the risk of death from breast cancer in women who have already been treated for the disease.
Michelle Holmes, associate professor of medicine and epidemiology at Harvard Medical School, who led the study published in the Journal of Clinical Oncology, said: "If these findings are confirmed in other clinical trials, taking aspirin may become another simple, low-cost and relatively safe tool to help women with breast cancer live longer, healthier lives."
Previous studies have suggested aspirin has a protective effect against breast cancer, as well as at least two other types of cancer: prostate and colon. Researchers on the latest study say it is not clear how it affects cancer cells but it may curb the spread of the disease by reducing inflammation, which is a key factor in cancer development.
The results showed that in addition to halving the risk of death, it also reduces metastases – spread of the cancer to other areas of the body – by a similar margin. Laboratory studies indicate that aspirin reduces the growth and invasiveness of breast cancer cells.