Development of a non-invasive diagnostic tool for early detection of bowel cancer
Lead researcher: Professor Nathalie Juge and Dr Dimitra Lamprinaki
Location: Quadram Institute Bioscience and Norfolk and Norwich University Hospital
Grant award: £25,000
Dr Dimitra Lamprinaki in Professor Nathalie Juge’s team investigated if a new blood test could be used, alongside the faecal immunochemical test (FIT), to give more accurate detection of bowel cancer.
The challenge
FIT is used in bowel screening and by doctors if someone has symptoms that need further investigation. It detects traces of blood in poo which can be a sign of a cancer or a pre-cancerous growth in the bowel.
However, sometimes FIT gives the wrong result. Someone without bowel cancer may get a positive result and have an unnecessary colonoscopy, while someone with bowel cancer may get a negative result, delaying their diagnosis.
The science behind the project
A particular type of bacterium which is found in the bowel is known to increase bowel cancer risk and is present at higher levels in cancerous tissues. Professor Juge’s team previously showed that it interacts with a protein on immune cells. Although the bacterium and the protein are in the bowel, there are markers of their presence in the blood and these markers are raised in people with bowel cancer.
This study tested how well these blood markers identify bowel cancer, using donated blood samples from people having a colonoscopy after an abnormal FIT result.
Results
The researchers collected blood samples from 436 patients having colonoscopies as part of the NHS bowel screening programme. Of these, 33 had bowel cancer and 45 were healthy controls — the rest of the patients had pre-cancerous changes such as polyps, or other bowel conditions like diverticulosis.
At this stage, the tested blood markers weren’t different enough between cancer and control samples to be able to confidently identify the people with cancer.
What difference will this project make?
Although these blood markers can’t be a new diagnostic test, these results are still useful information for the researchers. They’re now going to extend their work to exploring other possible signs of the bacterium.
Improving the accuracy of FIT by combining it with a simple blood test would benefit both patients and clinicians, by reducing the number of incorrect FIT results that lead down the wrong pathway. A false negative FIT result can give faulty reassurance and delay diagnosis of bowel cancer with potential impact on the chances of cure, while a false positive result can cause anxiety and mean patients undergo an unnecessary procedure, putting extra burden on colonoscopy services.
- Learn more about bowel cancer screening
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