Half (51%) of people invited to bowel screening for the first time in 2015 didn't take part, according to the latest figures from Cancer Research UK published today (Wednesday) in the European Journal of Cancer.
Averaged figures from 2010-15 in England showed that those from deprived areas were less likely to participate (43%) than those in wealthier regions (57%) and more women (56%) than men (47%) returned samples from the screening kits sent out in the post.
People who lived in ethnically diverse neighbourhoods were also less likely to take part (41%) than those who didn't (56%).
The current screening kit requires small stool samples to be taken on three separate days and posted back to the bowel screening unit in specially sealed envelopes.
Researchers from University College London (UCL) examined the anonymous data from 4.4 million men and women aged between 60 and 64 who were sent a home test kit for the first time as part of the English Bowel Cancer Screening Programme between 2010 and 2015.
They found that 53% returned samples in 2010, but this dropped to 49% by 2015.
For those who choose to take part in screening the risk of dying from bowel cancer is 25% lower than for those who don't.
Lead researcher Dr. Christian von Wagner from UCL said: "The fact fewer and fewer people are returning their kits and that inequalities in the system are widening, is very worrying. There is an urgent need to revolutionise bowel cancer screening because the earlier cancer is spotted, the more lives can be saved.
"Research has shown the introduction of a new test called the Faecal Immunochemical Test (FIT) would encourage more people to take part, with a 7% increase in uptake. The sooner this can be introduced, the more lives will be saved."
FIT is a new test due to be introduced into the national bowel screening programme in England this autumn. It is easier to use than the current test as it only requires one sample instead of three and is more accurate in detecting potential cancers.
Sara Hiom, director of early diagnosis at Cancer Research UK, said: "Our bowel cancer screening programme is extremely effective at detecting early disease before symptoms show themselves, so it's very concerning that so many people are missing out on this potential health benefit.
"We have good evidence to suggest that the new FIT screening test—which is easier to do—will help reduce barriers and result in more people choosing to take up their invitation. So the sooner it is introduced, and made available to everyone eligible, the better.
"When bowel cancer is diagnosed at an early stage, as through screening, more than 9 in 10 people survive but when it is detected in the late stages, survival falls to less than 1 in 10. Every year around 28,500 people aged 60 and over are diagnosed with bowel cancer in England.
Improved screening will undoubtedly reduce deaths from a cancer that affects so many lives."
Anne Parmenter, 63, from South London was diagnosed with bowel cancer through screening. Following surgery and chemotherapy she is now doing well and back at work as a classroom assistant.
She said: "On my 60th birthday, I received a bowel cancer testing kit in the post from the NHS. I wasn't going to do it but, in the end, I thought it was daft not to and sent it back. The following Tuesday I received a letter asking me to go to hospital for more tests.
"I had no symptoms before and didn't feel unwell, so I feel that kit saved my life. The cancer has changed how I look at life because none of us know what is around the corner. Three years ago, I had no idea of what was to come but I am now slowly recovering and getting back to normal."
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Hirst Y, Stoffel S, Baio G, McGregor L, von Wagner C, Uptake of the English Bowel (Colorectal) Cancer Screening Programme: an update 5 years after full roll-out, European Journal of Cancer (2018), DOI: 10.1016/j.ejca.2018.07.135