Colorectal cancer incidence among adults under 50 years is rising in 27 of 50 countries analysed, according to a new global study. Researchers examined trends across nations of varying development levels using data from the WHO–IARC Cancer Incidence in Five Continents Plus database.
The highest early-onset colorectal cancer rates were observed in Australia (16.5 cases per 100,000), followed by the USA, New Zealand, and South Korea. In contrast, the lowest rates were reported in Uganda (4.4) and India (3.5). For older adults, incidence peaked in the Netherlands (168.4) and Denmark (158.3) while remaining lowest in Uganda (45.9) and India (23.5).
Trends revealed an average annual percentage increase (AAPC) in younger adults in countries like New Zealand (3.97%), Chile (3.96%), and England (3.59%), surpassing growth rates in older populations. In 14 countries, rates stabilised or declined in older adults despite increases among younger adults.
The study highlights the urgency of identifying underlying causes and raising awareness to facilitate early detection. Men in countries like Chile and Argentina showed faster incidence growth, whereas women led the increase in England and Australia.
The findings suggest a pressing global health issue, particularly in nations experiencing exclusive or accelerated rises in early-onset cases. Proactive screening strategies and research into potential environmental, lifestyle, or genetic drivers are essential to combat this alarming trend.
Helena Bradbury, EMJ
Reference
Sung H et al. Colorectal cancer incidence trends in younger versus older adults: an analysis of population-based cancer registry data. Lancet Oncol. 2024;S1470-2045(24):00600-4.
