Screening has a critical effect on reducing bowel cancer incidence in England
Press release issued: 9 August 2023
Screening has reduced the incidence of bowel cancer finds a new study jointly led by researchers from the University of Bristol and University Hospitals Bristol and Weston NHS Foundation Trust.
The incidence of bowel cancer in the lowermost portion of the large bowel has decreased by approximately 15% following the introduction of the English Bowel Cancer Screening Programme (BCSP) in 2006. The findings also show that the most pronounced reductions in incidence were observed in men and in patients living in areas of greatest socioeconomic deprivation.
In this new study, published in Colorectal Disease, researchers wanted to investigate the impact of the BCSP on incidence rates of bowel cancer among adults in England. After its introduction in 2006, the BCSP was expanded in 2010 to offer screening to all adults aged 60 to 74 years registered with a GP in England. As part of the programme, adults in this age group are automatically sent an NHS bowel cancer screening kit every two years. The age of screening onset is currently being reduced with the NHS Long Term Plan committed to lowering the age threshold to 50 years by 2025.
Using data from the National Cancer Registration and Analysis Service database, the team identified 541,515 adults diagnosed with bowel cancer of screening age (60-74 years) between 2001 and 2017. Of these, 44% of patients had tumours of the uppermost portion of the large bowel (caecum to splenic flexure) and 56% had tumours of the lowermost portion (descending colon to rectum).
While the incidence rate of bowel cancer initially peaked in the years following the introduction of the BCSP, it subsequently decreased with the greatest reduction in incidence being observed in tumours of the lowermost portion of the large bowel. In 2001, the incidence of tumours of the lowermost portion of bowel was 11% higher in patients from the most deprived compared to the least deprived areas, reducing to 4% by 2017. Furthermore, men were also noted to have experienced a greater reduction than women over time-period of the study for tumours of both the uppermost and lowermost portions of the large bowel.
Mr Adam Chambers, one of the study's lead authors and an Academic Clinical Lecturer in Colorectal Surgery in the School of Cellular and Molecular Medicine at the University of Bristol, said: "Our results show that one of the benefits of screening people for bowel cancer is that there is a significant lowering of colorectal cancer incidence rates that is primarily driven by detecting and removing pre-cancerous polyps at colonoscopy.
"Future work should be focused on reducing the incidence of tumours of the uppermost portion of the large bowel by increasing screening uptake through use of the new faecal immunohistochemical test (FIT) and improving the quality of colonoscopy. We welcome the reduction in the screening age threshold, as our research group have previously demonstrated that bowel cancer incidence is rapidly increasing in young adults."
'Colorectal cancer incidence trends by tumour location among adults of screening-age in England: a population-based study' by Adam. C. Chambers et. al in Colorectal Disease [open access]