One-off blood tests could soon be used to pick up early cases of bowel cancer, potentially making it easier to detect the disease which is often missed. Bowel cancer, the fourth most common cancer in the UK, kills around more than 16,800 people every year, many of whom are diagnosed at late stage when survival rates are lower.
The Food and Drug Administration in the US has just approved the Shield blood test as a first-line screening option, which picks up DNA shed into the blood stream from colorectal tumours with a high degree of accuracy. The new test, which took 10 years to develop, has been approved for adults aged 45 and older who are at average risk for the disease. It was found to be just as effective as other more invasive tests in a study published earlier this year in the New England Journal of Medicine. Zac a Researchers at the Massachusetts General research Institute in Boston looked at 7861 patients who had already been diagnosed with colorectal cancer using colonoscopy in centres across the US. What they found was that 83.1% of the participants tested positive with the new blood test and 16.9% tested negative. Of those who tested positive, the test was able to pinpoint stage 1, 2 or 3 cancers with 87.5 % accuracy.
According to Cancer Research UK, there are around 44,100 new bowel cancer cases in the UK every year. Symptoms include a change in your normal bowel habit, blood in your poo, pain or feeling more tired than usual. People who are diagnosed early with the disease, at stage one when it hasn’t spread outside the bowel wall, have a 90 per cent chance of surviving five years but those whose cancer is caught at late stage 4, when the cancer has spread to the organs in the body, only have around a 10 per cent chance of surviving five years after their diagnosis. A study published in 2020 in Gut found that only 14.4% of bowel cancer cases in the UK were diagnosed at the earliest stage 1 and more than a quarter (29.7%) were diagnosed much later at stage 4.
Anyone aged between 54 to 74 years old in the UK is already eligible to have bowel screening checks on the NHS and the programme is gradually expanding to make it available to everyone aged 50 to 53 years.
The screening test used is called a FIT test which looks for blood in a poo sample. It is straightforward to do at home with a DIY kit. If blood is detected in the sample, the next stage is a colonoscopy, which is an invasive procedure to look inside the bowels using a fibre optic camera, and a biopsy, when tissue is taken to be examined under a microscope. Both involve sedation and a hospital visit.
Bowel cancer is treatable and curable if diagnosed early. Screening is one of the best ways to spot the disease early when it’s easier to treat and in some cases prevent it from developing by finding polyps (non-cancerous growths) in the bowel.
According to the latest UK government figures, during 2021-22, the NHS Bowel Cancer Screening Programme in England invited 5,924,232 people to participate in FOBt screening, and of these people 4,083,100 adequately participated (i.e., ‘were screened’), giving an uptake percentage of 68.9%.
- Tailor-made cancer vaccines - 7th March 2025
- One-off blood tests for bowel cancer - 7th March 2025
- Colon cancer takes sides - 7th March 2025