While cancer caused more than 170,000 deaths in 2023, including more than 90,000 men and nearly 67,000 women, French registers show a moderate but continuous increase in certain cancers among young adults for around twenty years. Nothing of an epidemic,but a weak,persistent signal,which intrigues epidemiologists.The figures, published in 2025 by Public Health France and the National Cancer Institute (INCa), confirm the trend.
Cancers in young peopel: what do the figures say?
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An incidence that is rising… moderately
The figures,this time,no longer really leave any room for doubt. According to the EPI-AJA study, published in 2025 by Public Health France and the National Cancer Institute (INCa), the overall incidence of cancer among 15 to 39 year olds increased on average by +1.62% per year between 2000 and 2014, before falling slightly by -0.79% per year between 2015 and 2020. Simply put, the trend is neither explosive nor linear, but very
Why Are more Young People Getting Cancer?
For years, a disturbing trend has been emerging: an increase in cancer diagnoses among younger populations. While overall cancer rates aren’t experiencing a widespread “explosion” as of 2015, specialists are observing a concerning shift – cancers are appearing in increasingly younger individuals. This is a subtle signal demanding careful interpretation, not panic.
But why are cancers affecting more and more young people?
Improved diagnosis: an amplification effect
One key description is simply better detection. Advances in medical imaging (MRI, CT scans, ultrasound), molecular biology, and organized screening programs now identify tumors earlier than ever before. This naturally leads to an increase in reported incidence.
However, this doesn’t account for everything. For cancers like glioblastoma (an aggressive brain tumor) and colon cancer in those under 40,the rise in cases extends beyond what screening alone can explain. Public Health France confirms this represents a genuine increase in diagnoses, meaning the disease is manifesting at earlier ages. Technology has broadened our view, but the disease itself is appearing sooner.
Modern lifestyles
Our behaviors have profoundly changed, and our bodies are reacting. Sedentary lifestyles, diets rich in ultra-processed foods, excessive sugar and fat consumption, overweight, and obesity are all clearly linked to an increased risk of several cancers, including those of the breast, colon-rectum, liver, and kidney, according to the WHO and Inserm.
Overweight is notably concerning. It’s linked to at least 13 recognized cancer sites by the International Agency for Research on Cancer (IARC). In France, the prevalence of overweight among young adults is rising. The Esteban 2023 survey reveals that one in five young people are now affected.
These behaviors are also starting earlier in life. We’re less active, spend more time sitting, and consume more processed foods.This weakens metabolism at a younger age, and chronic inflammation promotes the change of healthy cells into cancerous ones over time.
The chemical environment and early exposures
The other major factor is environmental exposure. Younger generations are born into and raised in an environment saturated with air pollutants, pesticides, plastics, heavy metals, and endocrine disruptors. These substances, found in air, water, food, cosmetics, and packaging, exert their effects at low doses but over extended periods.
Numerous studies from IARC and Inserm have confirmed the link between certain disruptors (like bisphenol A or phthalates) and hormone-dependent cancers, particularly of the breast and prostate. Researchers describe a cohort effect: each generation is born into a more “charged” environment, accumulating invisible exposures from fetal life. While precisely measuring this impact is tough, the signals are multiplying, and cancer is increasingly becoming a chemical barometer of our time.