The finding is based on an analysis of data from 38 studies that enrolled more than 2.7 million women, the largest of its kind, by researchers at the University of British Columbia, Vancouver Coastal Health Research Institute, and the University of Santiago de Compostela.
A separate analysis for Aspirin showed a 13 per cent relative risk reduction in breast cancer and an analysis for Advil showed a 21 per cent relative risk reduction.
The review, conducted by Dr. Mahyar Etminan, assistant professor of medicine at the University of British Columbia, and member of the Vancouver Coastal Health Research Institute, and Bahi Takkouche, professor of epidemiology at the University of Santiago de Compostela in Spain, alludes to a protective affect against breast cancer.
Previous studies have shown conflicting results that support and fail to support the use of non-steroidal anti-inflammatory drugs (NSAIDs), including Aspirin and ibuprofen (Advil), in reducing the risk of developing breast cancer.
Etminan warns that since most of the data is from observational studies, the results should be considered as hypothesis generating.
"The results are encouraging and may help us better understand the importance of role of inflammation in the pathology of the disease," says Etminan, who is also a scientist at the Center for Clinical Epidemiology and Evaluation at VCHRI.
"However, we don't recommend the routine use of NSAIDs for breast cancer prevention until large randomized trials confirm these findings. Results from an ongoing trial will be available in 2009," Etminan added.
The study is published in the U.S. Journal of the National Cancer Institute.