New AI blood test for bowel cancer could save lives by slashing huge backlog of cases

Scientists are rolling out a new ‘artificial intelligence blood test’ for bowel cancer that they hope will save lives by prioritising those who need a check-up straight away.

The Covid-19 pandemic has led to a huge backlog of patients awaiting a colonoscopy – the ‘gold standard’ examination for bowel cancer in which a tiny camera is inserted into the body to look for tumours.

More than nine in ten who undergo a colonoscopy will not have cancer, but for those who do, any delay to treatment can affect their chances of survival.

Now scientists have developed a blood test which is up to 96 per cent accurate in detecting bowel cancer, which they say can be used to bump those who most urgently need a colonoscopy up the list.

The CanSense-CRC test uses laser light and artificial intelligence (AI) to analyse a small blood sample for signs of proteins released by bowel cancer cells.

The CanSense-CRC test uses laser light and artificial intelligence (AI) to analyse a small blood sample for signs of proteins released by bowel cancer cells. [File image] 

It currently has a relatively high ‘false positive rate’ – when patients are flagged as having cancer when, in fact, they do not. As a result, a colonoscopy is still needed to confirm the result.

But scientists say the blood test could be used to great effect to prioritise the colonoscopy waiting list as it is cheap, quick and non-invasive.

Two hundred patients awaiting colonoscopies in Swansea are being offered it as a precursor to a wider rollout. They must be checked out after overcoming bowel cancer or having pre-cancerous lesions called polyps removed.

Colorectal surgeon Professor Dean Harris, who has been working to develop the test with a team at Swansea University, said there were 3,000 people in the city in this situation, some of whom had been ‘waiting years’.

Guidelines say such patients need a colonoscopy every one to three years, depending on circumstances.

However, Prof Harris said: ‘All that [checking] activity stopped in the pandemic, and now there’s a huge backlog, not just in Swansea, but everywhere.’

Some are getting checked out only if they develop potential symptoms of cancer – which could be too late.

Prof Harris added: ‘We want to help prioritise which patients need to be bumped up the list to have their colonoscopy done soonest, based on the result of this blood test.’ He believes the test could have a ‘massive impact’ on the waiting list, helping screen ‘not only [cancer] survivors but also to identify the disease in the first place’.

The tests currently cost about £100 each time – roughly a quarter of the cost of a colonoscopy – but Prof Harris said this would likely fall further as more tests were done. The initial rollout is being financed by the Moondance Cancer Initiative, Cancer Research Wales and the National Institute for Health and Care Research.