Will an aspirin a day keep prostate cancer at bay?
Not necessarily, according to new research.
Danish scientists say low-dose aspirin doesn't seem to reduce a man's risk of death from prostate cancer, but it may slow down the disease in some cases.
For patients with slow-growing, non-aggressive cancer, aspirin did appear to stop the cancer from progressing. A slight benefit was also seen among men who took aspirin for more than five years, the researchers found.
A small reduction
"Aspirin is widely used due to its established protection against cardiovascular diseases," said lead researcher Charlotte Skriver, from the Danish Cancer Society Research Center in Copenhagen. "Our results, however, do not suggest an overall protective effect of low-dose aspirin used in the year after prostate cancer diagnosis on mortality from prostate cancer."
But growing evidence suggests aspirin might reduce the risk of developing and dying from colon and other cancers, Skriver said. It was thought that prostate cancer could be added to that list.
Researchers did see a small reduction in prostate cancer deaths among patients who took low-dose aspirin for an extended time, she said. More study is needed to confirm that finding.
Skriver said any potential benefit from low-dose aspirin needs to be weighed against the risk of gastrointestinal bleeding linked with its use.
For the study, her team collected data on more than 29 000 men, average age 70, who were diagnosed with prostate cancer between 2000 and 2011.
During nearly five years of follow-up, more than 7 600 men died of prostate cancer and more than 5 500 died from other causes, the study found.
The findings were published in the Annals of Internal Medicine.
Dr Teemu Murtola, a professor of surgery at the University of Tampere in Finland, wrote an editorial that accompanied the study.
"Aspirin may have other benefits, but it is probably not helpful against prostate cancer," he said.
Murtola noted that aspirin was not associated in this large study with a lower risk of death from prostate cancer, despite promising previous laboratory studies.
Treatment not taken into account
Still, the risk was reduced among aspirin users in a subgroup of men with lowest-risk prostate cancer, he said.
"Future studies should aim to evaluate effects of very long-term, at least 10 years, of aspirin use on risk of prostate cancer death," Murtola said.
Dr Anthony D'Amico, a professor of radiation oncology at Harvard Medical School in Boston, said the study doesn't take into account the treatment patients received – an important point, because treatment directly affects survival.
Variables such as surgery, radiation and hormone treatment are essential to tease out the real effect of aspirin on survival, he said.
It's not only the treatments themselves, but the combinations used and the duration that can make a difference, D'Amico said.
"This is not definitive, because there is too much lacking in terms of treatment specifics," he said. "It's interesting, but it doesn't mean you should take an aspirin."
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