Using NHS patient data from the last 40 years, the research led by Adam Chambers at the University of Bristol and UH Bristol, looked at more than 55,000 cases of colorectal (bowel) cancer over 40 years in England.
Adam Chambers, Honorary Senior Research Associate in the School of Cellular and Molecular Medicine at the University of Bristol and Colorectal Registrar at UH Bristol, said: "Age has always been a major risk factor for bowel cancer, with the majority of cases being diagnosed in patients over 60 and therefore bowel cancer screening has focused on older age groups. However, this study shows that over the past 30 years, there has been an exponential increase in the incidence of bowel cancer among adults under 50."
The research, published in the British Journal of Surgery (BJS), describes in detail the demographic changes in colorectal cancer incidence among this younger population.
The study highlights that the increase in bowel cancer incidence in young people is predominantly driven by an increase in tumours of the lowermost portion of the bowel, specifically the sigmoid colon and rectum. While this increase does not appear to be associated with gender or socioeconomic status, there are some marked geographical variations.
The fastest increase in bowel cancer incidence was observed in southern regions, with an increase of more than ten per cent per year in the South West.
The study supports the findings from recent European and American studies that also showed the incidence of bowel cancer to be increasing quickly in young adults and, importantly, provides far greater detail on how this relates to the characteristics of the young adult population.
David Messenger, Consultant Colorectal Surgeon at UH Bristol and corresponding author, added: "Bowel cancer is becoming increasingly common in younger adults. Future research needs to focus on understanding why this trend is occurring and how it might be reversed, potentially through the development of cost-effective testing strategies that detect tumours at an earlier stage or polyps before they become cancerous."
The study was funded by the Medical Research Council (MRC), David Telling Charitable Trust and the Elizabeth Blackwell Institute (EBI).
Paper
'Demographic trends in the incidence of young-onset colorectal cancer: a population-based study' by Mr A C Chambers, Dr S W Dixon, Dr P White, Prof A C Williams, Mr M G Thomas, Mr D E Messenger in BJS [open access]