Can aspirin stop my cancer spreading? | Cancer Research UK
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Can aspirin stop my cancer spreading?

This page tells you about aspirin and whether it can lower the risk of cancer spreading. There is information about


Should I take aspirin

Research has been published showing that aspirin may help to prevent cancer and may also lower the risk of cancer spreading. These could be important findings but does not mean everyone, particularly people with cancer, should start taking aspirin. There are still some questions we need to answer about aspirin and cancer.

Aspirin can cause serious side effects for some people, such as internal bleeding. Some people with cancer already have a higher than normal risk of bleeding, because of their cancer or treatment. Some cancer drugs can also cause bad side effects when taken with aspirin.So it’s important that people with cancer talk to their doctors rather than deciding to take aspirin by themselves.

Aspirin can cause serious complications in people with other medical conditions such as asthma, stomach ulcers, or the blood clotting disorder haemophilia. 

Steroids and non steroid anti inflammatory drugs (NSAIDS) such as ibuprofen also irritate the stomach. So it is very important not to start taking aspirin without speaking to your doctor first if you take any of those.

If you are thinking of taking aspirin, do discuss the risks and benefits with your doctor first. If your doctor says that you can take aspirin, always eat something before taking it. Taking aspirin with food lines your stomach and lowers the risk of bleeding.

Remember there are other things you can do to lower your risk of developing cancer including

  • Eating a healthy diet
  • Keeping to a healthy weight
  • Giving up smoking
  • Taking regular exercise

The dose of aspirin

In trials so far, the amounts of aspirin taken each day varied from 75 to 300 mg. That’s between a junior aspirin (75mg) and one regular aspirin (300mg). If aspirin can help to prevent cancer or stop it spreading, we don’t know exactly how much aspirin people need to take.  As with any drug, it is important not to take too much because you could increase your risk of serious side effects.


Research into aspirin lowering the risk of cancer spreading

Research carried out so far shows that aspirin may lower the risk of dying from cancer and it may lower the risk of some cancers spreading to other parts of the body. But because aspirin can cause serious side effects for some people, it isn’t certain that the benefits of taking it always outweigh the risks.

A research study in 2012 looked at 5 trials which had been testing whether aspirin could prevent major heart and blood circulation problems in healthy people. People taking part in these trials were put into 2 groups. One group took aspirin every day and the other group had no treatment. The researchers then looked at all the people who went on to develop cancer in the 2 groups and compared

  • The types of cancer diagnosed
  • How many people who got cancer later developed cancer spread (secondary cancer)
  • How many people already had cancer that had spread when they were diagnosed

They found that in people who were diagnosed with an early stage (localised) cancer, those who took aspirin were less likely to develop a secondary cancer later on. So taking aspirin seemed to lower the risk of the cancer spreading.

The researchers also found that people taking aspirin were less likely to have a cancer that had spread when they were first diagnosed. A third fewer people who took aspirin had a spread of their cancer at diagnosis.

Another finding was that the greatest benefit was for a type of cancer called adenocarcinoma. Adenocarcinomas are cancers that develop in the epithelial glandular cells. These cells cover and line the body and the internal organs. So adenocarcinoma can start almost anywhere in the body. Many common cancers are adenocarcinomas, for example, breast and bowel cancers. In people taking aspirin who had adenocarcinoma, 70% fewer developed a secondary cancer than they would have expected.

In August 2014 an analysis of previous aspirin studies was reported in the Annals of Oncology. The study confirmed that aspirin can lower the risk of developing bowel, stomach and oesophageal cancers. It can also lower the risk of lung, prostate and breast cancers but not as much as the other cancer types.

Now, Cancer Research UK is helping fund the world's largest clinical trial looking at aspirin to stop cancer coming back. The ADD-Aspirin trial wants to find out if taking aspirin every day for 5 years can stop or delay an early cancer from returning. 11,000 people who have had, or are having, treatment for cancer of the bowel, breast, oesophagus (food pipe), prostate or stomach will take part. The trial will run for up to 12 years. It will compare 2 groups of people taking different doses of aspirin and another group taking dummy tablets (placebo). We have more information about the ADD-Aspirin trial on our clinical trials database.


Balancing the benefits and risks of aspirin

When looking for a medicine that can lower the risk of a large group of healthy people getting cancer, you also have to look at the risks it carries. You need to make sure that the benefits outweigh any harm the medicine may cause, because many people having the preventative treatment would never develop cancer anyway.

In the research studies so far, 2 or 3 people out of 1000 taking aspirin would die of strokes, bleeding or stomach ulcers. But 17 out of 1000 lives would be saved because people would avoid having cancer or heart attacks. 

The benefit of aspirin is not seen in people younger than 50. The benefit starts at the age of 50.

If you are thinking about taking aspirin, it is very important to talk to your doctor first. They can discuss with you the particular risks and possible benefits in your case and give you advice on the amount you should take. Because aspirin can cause these serious side effects, it is very important not to take too much.


Questions we need to answer about aspirin

So, there are still some unanswered questions about aspirin and cancer. We need to know which dose works best to lower the risk of cancer developing or spreading, while causing the least harm. We also need more research to find out

  • How long people should take aspirin for
  • What age people should start taking it
  • Whether some people are more likely than others to get side effects
  • Whether some people will benefit and others won’t
  • Whether we can lower the risk of having a stroke when people stop taking aspirin

Cancer Research UK is funding trials to try and answer these questions. You can find information about them on this website - go to the home page and type 'aspirin' into the search box.

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Updated: 6 August 2014