The benefits and risks of aspirin are becoming like coffee. It’s difficult to sort out all the studies providing conflicting evidence on whether it’s good or bad for you – or doesn’t make any difference. As recently as last month several studies came out which found no benefit from a daily aspirin for people with a median age of 74.
Like all studies you have to look carefully at who was studied. These studies were healthy older adults.
So now comes new research on aspirin use suggesting a benefit in two cancers. Nearly 100,000 nurses were followed for as many as 35 years. They were part of the famed Harvard Nurses Health Study. When researchers looked back at those women who developed ovarian cancer and those who didn’t, they found that taking a daily low-dose aspirin reduced the risk of ovarian cancer by 23%.
In a second study, over 130,000 people, including both the female nurses, and male health professionals, taking a daily standard aspirin reduced the risk of liver cancer by nearly 50%.
Sounds pretty impressive. Aspirin can prevent cancer so why not take it? Let’s look at the pros and cons of both of these studies and hear from the doctor who wrote the editorial that tried to put these studies in perspective for the physicians reading them.
- Large numbers of patients, followed for many years
- Top quality medical Journal (JAMA Oncology)
- Published by prestigious institutions (Harvard School of Public Health, Massachusetts General Hospital)
- These are two tough cancers
- Liver cancer rates are rising faster than any other cancer, and the authors note that there are “limited treatment options and median survival of less than one year.”
- Ovarian cancer is the fifth most common cause of cancer-related death among women with a poor prognosis and there is no effective screening test
- Significant benefits from aspirin use in both studies (23% and 49% reduction)
- We do not understand what dose is best, for how long and how aspirin could reduce the cancer risk
- One study showed standard dose worked. The other study said only low-dose worked, and standard dose did not
- Aspirin use increases the risk of bleeding
- These kinds of studies don’t prove that doing one thing causes another – they just showed that there was an association between aspirin use and reduced cancer risk
In addition in the liver cancer study, the benefits were seen in only one type of cancer. Dr. Tracey Simon, the lead author from Massachusetts General Hospital told SurvivorNet “there is not yet enough data to know which patients stand to benefit the most from aspirin therapy. Before we can use aspirin in a prevention strategy against primary liver cancer, we need to learn more about the benefits and risks of aspirin in different patient populations.”
Where does that leave us? Dr. Victoria Seewaldt, of the City of Hope Cancer Center, titled the editorial she wrote for the doctors who read this journal: “Aspirin and Chemoprevention: Have we arrived?” Chemoprevention means we would use aspirin to try and prevent ovarian and liver cancer. Doctors would tell their patients to take a daily aspirin. Dr. Seewaldt doesn’t think we are there yet.
She told SurvivorNet that “these studies, while very exciting, are the beginning and not the end. They are large epidemiological studies that test for associations.” Dr. Seewaldt said what is needed are clinical trials where one group takes aspirin, one group doesn’t and people are followed to see what happens.
But she says there are some people who might act on these studies. “I would urge people who are at risk for these cancers to work with a physician who specializes in risk for these diseases to talk about aspirin,” she said. As for the rest of us? “Low or average risk people should not take aspirin for cancer prevention.”