THURSDAY, Oct. 9, 2008 (HealthDay News) -- Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with a reduced risk for breast cancer, a new review suggests.
But the findings aren't an invitation for all women to start popping the popular painkillers, the researchers added.
"We don't want that to happen here, for people to jump on the bandwagon and start taking aspirin or ibuprofen," said study senior author Mahyar Etminan, an assistant professor of medicine at the University of British Columbia. "A lot of people are taking these drugs for aches and pains, and aspirin to prevent cardiac events. Those people may actually get an added benefit, but, for someone relatively healthy, we don't recommend starting to [reduce breast cancer risk] as of yet."
"From a practitioner's standpoint, it's kind of reassuring to patients if they do take NSAIDs for whatever reason," added Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "I don't think women should be taking these medicines for prevention, but if they are taking them for other reasons like heart prevention or arthritis, this should be reassuring."
The study is in the Oct. 15 issue of the Journal of the National Cancer Institute.
Use of NSAIDs has been linked to a lower risk of cancer overall, particularly colon cancer, and even to a lower risk of breast cancer, although studies looking specifically at breast cancer have produced inconsistent results.
With colleagues at the University of Santiago de Compostela in Spain, Etminan reviewed mostly observational studies which, together, involved a total of almost 3 million women.
The analysis included the group of NSAIDs known as cox-2 inhibitors, only one of which, Celebrex (celecoxib), is still on the market.
NSAID use across all participants in all studies was associated with a 12 percent lower risk of developing breast cancer. Aspirin was associated with a 13 percent reduced risk, and ibuprofen with a 21 percent reduced risk.
Different doses did not yield different results.
The authors acknowledged that, given that almost all of the studies reviewed were observational, this analysis may be subject to the certain limitations, and all such analyses are only as good as the studies they review.
On the other hand, the review was a large one and has biological plausibility. The inhibition of the enzyme cyclooxygenase (COX) is thought to be one of the ways NSAIDs might reduce cancer risk. And, according to an accompanying editorial, cox-2 is over expressed by 40 percent in invasive breast cancer and 80 percent in colorectal cancer.
At the very least, the results should prompt further research.
"The question is, how can you apply these results? These drugs are widely used but not without side effects. You're not going to put someone on ibuprofen long-term, because it's not going to help the stomach, and there are kidney effects," said Dr. Debra Monticciolo, a professor of radiology at Texas A&M Health Science Center and vice chair of research in the radiology department and chief of breast imaging at Scott & White Hospital. "This is preliminary. You're looking at an observational meta-analysis. It's not the strength of a randomized, controlled trial. You want long-term efficacy and long-term safety data. We need more information."
A randomized trial looking at the protective effect of Celebrex on breast cancer is due to be completed in 2009, Etminan said.
The American Cancer Society has more on breast cancer.