STEVE INSKEEP, HOST:
A new report suggests women who often use aspirin have a lower risk of melanoma, the deadliest kind of skin cancer. This is not the first study that finds aspirin might protect against melanoma, but it is one of the largest. And NPR's Richard Knox says this is far from the first hint that the lowly aspirin tablet may reduce the risk of a number of cancers.
RICHARD KNOX, BYLINE: Melanoma's been increasing in recent years, especially in young women. So anything that might reduce the risk is good news; especially if it's a cheap, common drug that millions of people take anyway to fight a headache, or reduce their risk of a heart attack.
The new study, in the journal "Cancer," looked at melanoma in 60,000 Caucasian women; light-skinned people have the highest risk of this cancer. Over a 12-year period, women who took aspirin at least a couple of times a week had a 20 percent lower risk of developing melanoma.
DR. JEAN TANG: In terms of cancer prevention, a lower melanoma risk by 20 percent is very large and significant.
KNOX: That's Dr. Jean Tang of Stanford University, the study's senior author. She says women who regularly took aspirin for five years or more had a 30 percent lower risk.
TANG: There's nothing else that I know of, that has as large of an effect as what we're seeing with aspirin.
KNOX: Most of the women took a regular dose, not a baby aspirin. But this study just observed whether women chose to take aspirin or not, and then correlated that with whether they got melanoma. So it doesn't prove anything.
TANG: We would have to do a large clinical trial, randomizing women to receive aspirin versus placebo; following them for 10-plus years.
KNOX: And Tang says that gold-standard type of study isn't likely to happen.
TANG: It's just too expensive to do.
KNOX: So this study, like so many others, leaves open the question: What should anybody do?
TANG: I know you want to pin me down and say, should women go out and take aspirin for melanoma? In somebody who's at high risk for melanoma, I would say that taking aspirin is a good idea.
KNOX: Tang says high risk means anybody who's already had skin cancer - either melanoma, or less dangerous kinds. Either one is an indicator of how much sun damage their skin has had. People who sunburn easily, and don't tan so much, are also at higher risk for melanoma.
Some cancer researchers say this new melanoma paper adds to a pile of studies over the past decade, suggesting that aspirin lowers the risk of many cancers: colon, breast, esophagus, stomach, prostate, bladder and ovary.
Dr. Randall Harris, of Ohio State, is pretty convinced that aspirin prevents cancer by damping down a master gene called Cox-2, that prevents inflammation. Harris thinks it's reasonable for folks to take some aspirin for its anti-cancer effects.
DR. RANDALL HARRIS: You don't need to take too much. You just need to reset the inflammatory mechanism, in my opinion. And so, you can get by with just a couple of tablets a week. That's what I do - been doing it for a long time.
KNOX: But Eric Jacobs, of the American Cancer Society, says that's premature.
DR. ERIC JACOBS: There've been about eight studies that have looked at aspirin and melanoma. And about half of them find slightly lower risk. And half of them find no connection at all. You look at the totality of the evidence and right now, it's rather mixed.
KNOX: Jacobs says it's important to remember that aspirin is a real drug with real side effects. It can cause serious and even fatal stomach bleeding, even at low doses. But skeptics like Jacobs agree with enthusiasts like Jean Tang on one point.
TANG: The worst thing would be, I can take aspirin and that justifies me doing indoor tanning. That is not the right message.
KNOX: She says one reason melanoma's rising fast among young women is that so many of them love those tanning booths.
Richard Knox, NPR News