But other NSAIDs — nonsteroidal anti-inflammatory drugs — like Advil, Motrin, Nuprin, and Aleve, do not, the research suggests.
"If you're already taking aspirin for its heart-protective properties, you may be getting an added benefit," says researcher Aditya Bardia, MD, MPH, of the Mayo Clinic in Rochester, Minn.
But that doesn't mean women should start popping aspirin in hopes of warding
off cancer, he tells WebMD.
"Aspirin may have anticancer effects, but it also has it own risks, chiefly
an increased risk of gastrointestinal bleeding. Talk to your doctor about the risks and benefits," Bardia says.
Bardia notes that previous studies on the topic have had conflicting results, with some showing that both aspirin and nonaspirin NSAIDs protect against cancer, particularly colon and breast cancer, and others suggesting they do not.
The new study, presented at the annual meeting of the American Association
for Cancer Research, is noteworthy both for its large size and long follow-up, he says.
The study included 22,507 cancer-free postmenopausal women aged 55 and over
who participated in the Iowa Women's Health Study. At the start of the study, all the women were asked about their use of aspirin and other NSAIDs.
Of the total, 72 percent said they used aspirin, 39 percent used nonaspirin NSAIDs, and 28 percent used both aspirin and nonaspirin NSAIDs.
Over the next 12 years, 3,487 women developed cancer and 3,581 died from it. Results showed that those who used aspirin at least once a week were 15 percent less likely to develop cancer and 9 percent less likely to die from it than women who never used the painkiller.
The more aspirin they took, the greater the benefit: Women who took it six or more times a week were 19 percent less likely to develop cancer and 18 percent less likely to die from it than nonusers.
But regular use of the other NSAIDs offered no such protection, Bardia says. Additionally, current smokers did not appear to get the same benefits from aspirin, although former and never smokers did, he says.
Mike Xu, PhD, a member of the ovarian cancer program at Fox Chase Cancer Center in Philadelphia, says his own studies in mice show aspirin protects against ovarian cancer.
Xu tells WebMD he is surprised the other NSAIDs studied didn't offer benefits as well.
All of the drugs block the effects of enzymes known as Cox-1 and Cox-2 that play a key role in making prostaglandins. Prostaglandins can drive inflammation, pain, and swelling and possibly stimulate cancer development in a number of organs throughout the body, so blocking them should prevent these effects, he explains.
"I would have expected similar results with all of the drugs," Xu says.
The researchers did not look at a newer type of prescription NSAID called Cox-2 inhibitors that affect only Cox-2 enzymes and not Cox-1. Two of them, Bextra and Vioxx, are no longer sold because of concerns about their side effects. The third, Celebrex, is still available.
By Charlene Laino
Reviewed by Louise Chang
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