Older women who take an aspirin regularly may be lowering their risk of developing the deadly skin cancer melanoma, a recent study suggests.
And the longer postmenopausal women take aspirin, the more melanoma risk appears to diminish.
The effect is only seen with aspirin, not with other pain relievers such as acetaminophen (Tylenol), the researchers noted.
Each year in the United States there are nearly 77,000 new cases of melanoma and more than 9,000 deaths from it, according to the US National Cancer Institute.
For the study, the research team collected data on nearly 60,000 white women who were part of the Women's Health Initiative, a long-term national study. The women, aged between 50 and 79, were asked about what medications they took and other lifestyle preferences.
Over 12 years of follow-up, the investigators found that women who took aspirin had a 21% lower risk of developing melanoma compared with women who didn't take aspirin.
The study found that women who took aspirin for at least five years had their melanoma risk drop by 30%, compared with women who didn't take aspirin.
To try to isolate the effect of aspirin on melanoma, the researchers accounted for other factors such as skin tone, tanning and use of sunscreen.
The new report was published in Cancer.
More Study Needed
But it's too soon to make firm conclusions, a researcher cautioned.
"Aspirin could be potentially used to prevent melanoma, but a clinical trial is needed," said lead author Jean Tang, MD, PhD, an assistant professor of dermatology at Stanford University.
This type of population-based study can only show an association between aspirin and the reduced risk for melanoma, not that aspirin actually helps prevent it.
Dr. Tang doesn't believe women should start taking aspirin solely to try to prevent melanoma. "It's too early to say this," she said.
It is possible that aspirin's anti-inflammatory properties might be responsible for lowering the risk of melanoma, Dr. Tang suggested.
"Aspirin may also promote cell death of melanoma cells," she added.
Whether a protective effect also occurs in men is not known, said Dr. Tang, who plans to look at that in her next study.
One expert doesn't see any problem taking aspirin to prevent melanoma, especially for people with a family history of the disease.
Prolonged use of aspirin is not without risks, including stomach bleeding, but the benefits of preventing melanoma outweigh the risk for vulnerable people, said Michele Green, MD, a dermatologist at Lenox Hill Hospital in New York City. She praised the recent research.
"I think it's fantastic. It's really a remarkable study," Dr. Green said.
"If you have a family history of melanoma, I don't see any downside of taking aspirin for this," she said. "I would urge my patients who have a family history of melanoma to take aspirin based on this study."