Common painkillers reduce breast cancer risk

A REVIEW of scientific evidence has found that common painkillers reduce the risk of breast cancer by up to 21%.

Scientists pooled together data from 38 studies involving more than 2.7 million women from five countries.

The results showed that regular use of drugs such as aspirin and ibuprofen lowered the risk of breast cancer by 12% compared with no use.

A separate analysis for aspirin showed a 13% risk reduction, while ibuprofen on its own reduced the chances of developing breast cancer by 21%.

Both belong to a class of medicines known as non-steroidal anti-inflammatory drugs (NSAIDs), which work by inhibiting two enzymes in the body linked to the immune system.

Cox 1 and 2 enzymes help to drive inflammation, and are thought to play several roles in the promotion of cancer.

They are believed to affect processes such as cell proliferation and death, the generation of blood vessels that feed tumours, tissue invasion by cancer cells, and immune responsiveness.

Previous studies looking at whether painkiller drugs can protect against breast cancer have produced conflicting results.

Some suggested the drugs help prevent cancers while others have not.

By combining results from a number of investigations, it is often possible to get a clearer picture of subtle trends than individual studies can provide.

The review, published in the US Journal of the National Cancer Institute, supports the theory that inhibiting cox enzymes with aspirin-like drugs can reduce the risk of breast cancer.

Dr Mahyar Etminan, from the University of British Columbia in Canada, who led the research, said: “The results are encouraging and may help us better understand the importance of the role of inflammation in the pathology of the disease.

“However, we don’t recommend the routine use of NSAIDs for breast cancer prevention until large randomised trials confirm these findings. Results from an ongoing trial will be available in 2009.”

Dr Sarah Rawlings, head of policy at the charity Breakthrough Breast Cancer, said: “The potential of anti-inflammatory drugs, such as aspirin, to lower the chances of developing breast cancer is very interesting but as the researchers say, large-scale trials are needed to confirm these findings.

“Anti-inflammatory drugs can have potentially serious side-effects when taken over a long period. Until the long-term effects of taking these drugs for breast cancer prevention are known, we would urge women worried about their risk of breast cancer to talk to their GP.”