A study published in The Lancet Oncology in January 2025 revealed that colorectal cancer diagnoses are rising among younger adults worldwide – and England is among the hardest hit. Analysing data up to 2017 from 50 countries, researchers found that in 27 of them, bowel cancer rates in individuals aged 25–49 have steadily increased over the past decade.
The most dramatic annual increases were recorded in New Zealand (3.97–4%), Chile (3.96–4%), Puerto Rico (3.81%), and England (3.59–3.6%). In comparison, older adults (aged 50–74) in many of those countries either saw stable or declining rates. What could be the reason behind this worrying demographic shift?
“Colorectal cancer incidence trends in younger versus older adults: an analysis of population-based cancer registry data”, Hyuna Sung et al:
https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045%2824%2900600-4/fulltext
The Rise of Bowel Cancer in England
England’s 3.6% annual rise in early-onset cases is the fastest in Europe, marking a 52% increase since the early ’90s. Despite young-onset cases still being relatively rare – only about 1 in 20 bowel cancer diagnoses in the UK occur in the under‑50s – this rapid increase remains deeply concerning.
In addition, young women in several countries, including England, have shown faster increases than men, which also suggests that complex sex-based risk factors are also at play.
Why is this happening?
The medical community remains in the early stages of understanding the underlying causes. The Lancet authors suggest a potent combination of:
- Junk food and ultra‑processed diet: High consumption of processed meats, sugars, seed oils, emulsifiers, and reduced fibre intake may disrupt gut health.
- Obesity epidemic: Increasing global rates are tightly linked to cancer risk.
- Physical inactivity: Sedentary lifestyles are strongly associated with colorectal cancer.
- Microbial toxins: Emerging research links childhood exposure to colibactin (a toxin from certain E. coli) with early-onset cases – colibactin-induced mutations were found 3.3× more in those diagnosed under 40 compared to older patients:
https://news.cancerresearchuk.org/2025/04/23/colibactin-e-coli-early-onset-bowel-cancer
These factors align with findings by Sung et al. in The Lancet Oncology: “nutritional attributes, physical inactivity, and excess bodyweight” are top suspects.
Not Just in The West
While early-onset colorectal cancer was once seen as a Western phenomenon, this study reveals it is truly global – spanning Latin America, Asia, Oceania, and parts of Europe and Africa. High-income countries show the strongest rises, but even middle-income countries are reporting increases.
The Problems Caused by this Rapid Rise in Bowel Cancer
For one, it signifies a reversal of progress. Where previously, older age groups saw stable or declining rates, this surge among the young threatens to offset decades of success in cancer control, which will possibly also impact the older generation.
The burden of healthcare also shifts. Treating younger patients involves longer life expectancy but also more years living with treatment side-effects and psychological challenges.
On top of that, younger people are more likely to suffer delayed diagnoses, as both patients and doctors often overlook symptoms – rectal bleeding, abdominal pain, changed bowel habits, unexplained weight loss – leading to late-stage diagnosis and poorer outcomes.
What The Experts Say
Hyuna Sung (American Cancer Society), lead author: “The increase in early‑onset colorectal cancer is a global phenomenon… documented in various economies and regions.”
Michelle Mitchell (Cancer Research UK): “Rates in younger adults are still very low compared to over‑50s, but we need to understand what’s causing this trend.”
David Robert Grimes (Trinity College Dublin): Urged caution, noting differences in registry quality may affect country comparisons.
Katrina Brown (Cancer Research UK): Pointed out England’s fast rise vs Wales, Scotland and Northern Ireland requires further investigation; small case numbers in devolved nations can affect trends.
Dr. Ramamoorthy (surgical expert): Emphasised raising awareness among surgeons and primary care about the lowered screening age (now 45 in many places) and the need for symptom vigilance.
What can we do about it?
Raising awareness of potential symptoms of bowel cancer is always at the top of the list of priorities – both within primary care and among younger adults. The focus should, as usual, also be on targeted prevention – developing public health tools to reduce obesity, inactivity and poor diet, especially ultra‑processed foods. It is obvious that the message still isn’t getting through.
There is also ongoing research, including the international PROSPECT initiative, funded by Cancer Grand Challenges, to uncover microbial, dietary, and genetic triggers:
https://www.cancergrandchallenges.org/prospect
Screening is very important, and many countries have recently lowered the screening onset age of colorectal cancer, e.g., to 45 or even younger for high-risk groups.
And lastly, we need better, uniform cancer registries on a global scale for improvements in the quality of data and trend comparisons.
In summary
Early-onset bowel cancer is no longer a rarity – it’s a rising global health emergency. With nearly three-quarters of analysed countries reporting increases, and high-income nations like England seeing sharpest rises, urgent multi-pronged action is needed. Preventive public health measures, better awareness, more research into causes (like diet, obesity, and gut microbes), and younger screening could help turn the tide – but the clock is ticking…
