What is the evidence that aspirin lowers the chance of getting bowel cancer?
In a recent study:
- People with Lynch syndrome took aspirin every day, for at least 2 years.
- This lowered their chance of getting bowel cancer in a 10-year period.
- Taking aspirin didn’t have an effect straightaway but it lowered the chance of getting bowel cancer for many years after people stopped taking it.
- These pictures show the number of people with Lynch syndrome who got bowel cancer over 10 years, with and without taking aspirin.
Number of people with Lynch syndrome who got bowel cancer over 10 years
People who took aspirin
7 out of 100 people got bowel cancer
People who did not take aspirin
13 out of 100 people got bowel cancer
This information is based on the NICE decision aid for taking aspirin, edited by the Lynch Choices™ team.
It is not known how taking aspirin every day lowers the chance of getting bowel cancer. However, this has been found in scientific studies over many years. This includes studies of people with Lynch syndrome and people without Lynch syndrome.
Experts agree that daily aspirin should be recommended to people who have a higher chance of getting bowel cancer due to family history of bowel cancer or a genetic condition such as Lynch syndrome.
These images show the number of people with Lynch syndrome who got bowel cancer during 10 years of the CaPP2 study, with and without taking aspirin.
You may notice that the number of people who got bowel cancer without taking aspirin in the CaPP2 study is different from your own chance of getting bowel cancer (which you can see here). There are two reasons for this:
- The CaPP2 study looked at people who got bowel cancer over 10 years whereas your chance of getting bowel cancer is calculated over your lifetime (up to the age of 75).
- The number of people who got bowel cancer in the CaPP2 study includes all people with Lynch syndrome (including variants in any of the four genes, male and female), whereas your chance of getting bowel cancer is individual to you as it is based on your particular gene, whether you're male or female, and your age.
It’s important to understand that this study compared taking 600 mg of aspirin every day with taking a dummy tablet which didn’t contain any medicine. However, 600mg is a higher dose than people with Lynch syndrome are commonly advised to take.
You can read more about the CaPP2 study here if you would like.