Women who regularly take aspirin significantly reduce their risk of dying from breast cancer, according to a large new study published in the journal Cancer Research. The study is the latest to show that aspirin and some other pain relievers can help prevent cancer and lower the risk of it spreading to other parts of the body.
In the breast cancer study, Irish researchers analyzed the health records and pharmacy claims of nearly 2,800 women diagnosed with stage I-III breast cancer.
“Our findings suggest that aspirin could play a role in reducing mortality from breast cancer by preventing the cancer spreading to nearby lymph nodes,” said lead author Ian Barron, PhD, Trinity College in Dublin
“We found that those women prescribed aspirin in the years immediately prior to their breast cancer diagnosis were statistically significantly less likely to present with a lymph node-positive breast cancer than non-users. The association was strongest among women prescribed aspirin regularly and women prescribed higher aspirin doses. We now need to establish how and why this is the case.”
The study was observational and did not look at the reasons why aspirin appears to slow the spread of cancer. But the findings are consistent with previous research that found aspirin use was associated with a reduction in cancer mortality and the risk of developing metastases.
The most prominent side effect of regular aspirin use is gastrointestinal bleeding.
“These results do not mean that women should start taking aspirin as a precautionary measure. Aspirin can have serious side effects. We still need to identify exactly how aspirin may prevent breast cancer from spreading to the lymph nodes; which women, or types of breast cancer, are most likely to benefit from taking aspirin; as well as what the optimum doses might be,” said co-author Kathleen Bennett, a professor in the Department of Pharmacology & Therapeutics, School of Medicine, Trinity College Dublin.
Another study published in the journal Cancer Research found that obese women recovering from breast cancer might halve their chances of the cancer reoccurring if they take aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) regularly.
Researchers followed 440 breast cancer survivors — most of them past menopause and overweight — who had estrogen receptor-positive breast cancer. Of the 440 women, 159 used aspirin or NSAID pain relievers. The other 281 women did not take pain relievers.
After seven years, 12% of the women who did not use pain relievers had a recurrence of cancer, while only 6% of the women taking pain medication did.
It also took longer for the cancer to reoccur, about 6.5 years in the pain medication group, compared to 4.2 years for the non-users.
Being overweight can cause inflammation, and both aspirin and NSAIDs have anti-inflammatory properties. Researchers think the pain relievers also make hormone therapy more effective for obese women being treated for estrogen receptor-positive cancers.
Risk of Cancer in Men Also Reduced
Another recent study found that aspirin can significantly reduce the risk of developing and dying from major cancers of the digestive tract – for both men and women.
Researchers at Queen Mary University in London found that taking aspirin for 10 years could cut bowel cancer cases by around 35% and deaths by 40%. Rates of esophageal and stomach cancers were also cut by 30% and deaths from those cancers were reduced 35 to 50%.
To reap the benefits of aspirin, people had to take a daily dose of 75-100 mg for at least five years when they were between the ages of 50 and 65. The study was funded by Cancer Research UK and published in the cancer journal Annals of Oncology.
“It has long been known that aspirin – one of the cheapest and most common drugs on the market – can protect against certain types of cancer. But until our study, where we analyzed all the available evidence, it was unclear whether the pros of taking aspirin outweighed the cons,” said Professor Jack Cuzick, Head of Queen Mary University’s Centre for Cancer Prevention.
Cuzick estimates that if everyone aged 50 to 65 started taking aspirin daily for at least 10 years, there would be a 9% reduction in the number of cancers, strokes and heart attacks in men and around 7% in women. The total number of deaths from any cause would also be lower, by about 4% over 20 years.
“Whilst there are some serious side effects that can’t be ignored, taking aspirin daily looks to be the most important thing we can do to reduce cancer after stopping smoking and reducing obesity, and will probably be much easier to implement,” said Cuzick.