April 17, 2007 (Los Angeles) -- Humble aspirin comes through again. Already known to protect against heart disease, the popular painkiller also appears to lower a woman’s risk of developing or dying from cancer, a new study shows.
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% said they used aspirin, 39% used nonaspirin NSAIDs, and 28% used both aspirin and nonaspirin NSAIDs.
Over the next 12 years, 3,487 women developed cancer and 3,581 died, including 1,193 who died from cancer. Results showed that those who used aspirin at least once a week were 15% less likely to develop cancer and 9% 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% less likely to develop cancer and 18% less likely to die from 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.