NPR’s Richard Knox has been around the block a few times – a veteran science journalist. And it shows in the way he covered a study pointing to an association – women who took aspirin had fewer diagnoses of melanoma.
Emphasis on association, not causation.
He allowed one of the author’s enthusiasm to come forth – because that’s what she said:
“We’re really excited aspirin could be used as a potential preventive agent for melanoma,” Dr. Jean Tang of Stanford University Medical School, the study’s senior author, tells Shots. “In terms of cancer prevention, a lower melanoma risk by 20 percent is very large and significant.”
Tang says women who regularly took aspirin for five years or more had a 30 percent lower risk.
“There’s nothing else that I know of that has as large an effect as what we’re seeing with aspirin,” Tang says.
But Knox followed that with the kind of counter clarification that we think is essential in stories about observational studies. He wrote:
The data came from the 22-year-old, federally financed Women’s Health Initiative. But this study merely observed whether women chose to take aspirin or not, and then correlated that with whether they got melanoma. This kind of “observational” study doesn’t prove anything.
“We would have to do a large clinical trial, randomizing women to receive aspirin versus placebo, following them for 10-plus years,” Tang says.
She acknowledges that type of gold-standard study isn’t likely to happen because “it’s just too expensive to do.”
So this study (like so many others) leaves open the question: What should anybody do?
He ends with this important context:
But skeptics … agree with enthusiasts … on one point: “The worst thing,” Tang says, “would be [for people to think], ‘I can take aspirin, and that justifies me doing indoor tanning.’ That is not the right message.”
Tang says one reason melanoma is rising fast among young women is that so many of them love those tanning booths.
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