Could a blood test be used to diagnose bowel cancer?

One of our medical advisors, Professor Ian Tomlinson – and his team, have recently been awarded £500,000 by Cancer Research UK to investigate whether a blood test could be used to detect early signs of bowel cancer. We asked Professor Tomlinson to tell us more about this exciting research and explain what this could mean for the future of bowel cancer screening.  

What is this research looking at?

I’m working with researchers, both in the UK and in Denmark, to see whether it’s possible to detect DNA from bowel cancer cells in someone’s blood.

To test how well it works, we’ll look at blood from people who we know have had bowel cancer and people who have had polyps (non-cancerous growths) removed. We’ll also look at blood samples from ‘healthy’ people, to give us a comparison.

We are trying to develop a test that can find both polyps and bowel cancer (and tell the difference between the two). We hope this will help improve the way bowel cancer screening programme works, as well as reducing pressure on stretched NHS services.

Why is this sort of blood test needed?

At the moment, the NHS uses a test that looks for blood in poo to look for signs of bowel cancer or polyps. This test is used as part of the national screening programme, for people without symptoms of bowel cancer.

Bowel cancer screening is the best way to detect bowel cancer at the earliest stage and ultimately save lives. But as with any test, it’s not 100% reliable. An improved version of the current screening test is on the horizon, but to really make progress we need to think about different ways of detecting the disease.

Looking at DNA from cancer cells (known as circulating tumour DNA) is an exciting area of research, but we don’t yet know if it could be used to help diagnose bowel cancer or decide who needs further tests.

What difference will this research make?

Our project will initially last two years. At the end of the project, we’ll know whether or not this sort of test might work on a wider scale. If it shows potential, we’ll need to do more research to make sure it’s a reliable test and that it would be cost effective to roll this out as part of the wider screening programme for bowel cancer.

In the future, this could mean doctors have a much more accurate way of knowing which patients need further tests after their screening test. One day, it could be an alternative to the current screening test, although in the near future, we see the two tests working together. This means we have the chance to diagnose bowel cancer earlier – when there’s a better chance of successful treatment – in even more people.