Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen could play an important role in both preventing and treating breast cancer, suggests a review of clinical studies over a 27-year period.

But the researchers caution that further work is needed to determine the optimum type, dose and duration of NSAID treatment in this context, and to pin down whether the benefits of regular use outweigh the associated side-effects, especially in high-risk groups.

Professor Ian Fentiman and Avi Agrawal from Guy’s Hospital in London, UK looked at 21 studies of NSAIDs and breast cancer published between 1980 and 2007, involving more than 37,000 women in total. Their findings were published in the March issue of the International Journal of Clinical Practice (62.3, pp 444-449).

The review encompassed 11 studies of women with breast cancer and 10 studies that compared women with or without the disease. Some of the trials found no links between NSAIDS and reduced levels of breast cancer, while others indicated that taking NSAIDs could reduce the risk of breast cancer by about a fifth.

“Having weighed up the findings from over 20 studies, we have concluded that NSAIDs may well offer significant protection against developing breast cancer in the first place and may provide a useful addition to the treatment currently available to women who already have the disease,” Professor Fentiman commented.

“Recent studies of NSAIDs use have shown about a 20% risk reduction in the incidence of breast cancer, but this benefit may be confined to aspirin use alone and not other NSAIDs,” he added.

Moreover, the review did not examine the potential side-effects of using NSAIDs on a regular basis, such as gastrointestinal bleeding and perforation, Professor Fentiman pointed out.

“It would be essential to take these negative effects into account before we could justify routinely using NSAIDs like aspirin to prevent breast cancer,” he stressed.