Over the course of two decades, a thousand patients across the world have taken part in a study that required them to take two aspirins every day, a food supplement or a placebo.
They all had Lynch syndrome, an inherited condition that increases their risk of colorectal cancer - such as colon cancer or endometrial cancer.
By 2011, findings revealed that of the 861 people involved, 34 in the placebo group had bowel cancer. But among the 427 who were taking aspirin, only 19 were diagnosed.
The findings were clear. Aspirin had almost halved the number of people diagnosed with cancer in the group.
In this blog, we’re exploring the steps that led to these monumental findings, and the inspiring work Professor Sir John Burn is doing to pave the way for cancer prevention. Read on to find out more.
One in two people
One in two people will be diagnosed with cancer in their lifetime.
And though we’ve made great strides towards a cure, we still have a long road ahead of us.
But what if this disease could be mitigated by something that’s often found in our medicine cabinet? What if even those who are at a high risk of getting cancer could significantly improve their chances by taking two, tiny tablets every day?
Introducing Professor Sir John Burn and CaPP
At the heart of this research is Professor Sir John Burn.
Chairman of the Newcastle-upon-Tyne Hospitals NHS Foundation Trust, he is Professor of Clinical Genetics at Newcastle University and one of three principal investigators at the centre of the Cancer Prevention Programme. Otherwise known as CaPP.
Professor Burn launched the programme in 1993, after contributing to the international research community that discovered the APC gene. Spelling mistakes in this gene can run in families, and carriers of these faulty genes develop hundreds of polyps, little lumps in the lining of the bowel, during their teens. This can lead to cancer developing at a young age. To prevent this, an operation is offered when they reach adulthood, to take out the colon.
Professor Sir John Burn, alongside colleagues Professors John Mathers and Tim Bishop, began to think about different ways to treat gene carriers to prevent these polyps developing or, at least, slow the process down.
And it is this research that has identified aspirin as a treatment for Lynch syndrome. Many patients identified with the underlying gene defect that causes Lynch syndrome are now prescribed aspirin, which seems to slow down the growth of cancer cells as it’s thought aspirin switches off a protein overactive in bowel cancer cells.
How did CaPP identify aspirin as a cancer preventer?
It’s estimated that one in 300 people suffer from Lynch syndrome in the UK, and around one in thirty bowel cancer cases are associated with the genetic condition.
Prof Sir John Burn and the team asked that each of the 861 participants take either two aspirins daily, or a placebo, for at least two years.
“Taking aspirin has the potential to save thousands of lives worldwide and is clear evidence of the value of long-term studies showing simple steps that can be taken to improve people’s lives.”
Though there was no change in bowel cancer incidence between the two groups in the first analysis in 2007, the second analysis three years later painted a very different picture and, over time, the protective effects of aspirin became clear.
By 2010, there were 34 new cases of cancer among those who took the placebo, compared to 19 among those who took aspirin - a 44% reduction in cancer diagnoses.
And further analysis of the patients who took aspirin for at least two years saw an even more profound effect revealing a 63% reduction in bowel cancer.
Follow-up research published in 2020 showed that when all the people in the study were included, even those who had taken aspirin for a shorter time, reduced their risk of cancer. This was recognised by the American Society of Clinical Oncology the most important advance in cancer prevention of the year.
What are the side effects?
Aspirin is already well known to reduce the risk of a heart attack in high-risk patients.
Other studies have suggested the pain killer has the power to reduce the risk of cancer. But this was the first randomised control trial, specifically for aspirin and cancer, to prove it.
However, there are side effects to the long-term usage of aspirin, such as stomach ulcers and strokes. But, for a reduced risk of cancer and improved life expectancy, a step Prof Sir John Burn feels Lynch syndrome patients may be willing to take.
"If we can prevent 10,000 cancers in return for 1,000 ulcers, in most people's minds that's a good deal."
What does the future of cancer prevention look like?
The cancer-preventing role of aspirin has been confirmed. Now, the next step for the CaPP team is to fine-tune the dosage.
Namely, can we identify a dosage that retains aspirin’s cancer-preventing powers, without the patient being at risk of stroke or stomach ulcers?
“Aspirin has a major preventative effect on cancer but this doesn’t become apparent until at least four years later. With the help of these dedicated volunteers, we have learned something of value to us all.”
But the ramifications of this research are much more far-reaching, and could have implications for each and every one of us. Currently, the CaPP team is working to identify whether aspirin should be used in the general population to prevent cancer and, as a result, reduce the number of people being affected by the disease.