Dramatic increases in early-onset cancer have been observed worldwide over the last two decades, with some rates doubling. While improved diagnostic awareness may account for part of this surge, researchers are urgently investigating whether actual case numbers are rising, particularly in regions like Latin America where colorectal cancer is becoming increasingly common among younger populations.
Data from the World Cancer Research Fund (WCRF), which analyzed registry records from England, the United States, and the Netherlands, reveals that new cancer cases increased for seven different types in England alone. In the UK specifically, colorectal cancer diagnoses in people under 50 rose from approximately one in 26,000 in 2001 to one in 12,000 by 2023. However, Amy Berrington de Gonzalez, a professor of clinical epidemiology at the Institute of Cancer Research in London, emphasized that these remain statistically small numbers. “Three times a small number is still a small number,” she told DW, noting that cancer is still uncommon among young adults overall.
The trend is particularly pronounced in Latin America. A 2025 study examining data from 50 countries found early-onset colorectal cancer rising in 27 regions. Chile saw annual increases of nearly 4%, while Argentina, Ecuador, Costa Rica, and Puerto Rico also reported significant spikes. Hospital data from Brazil’s A.C. Camargo Cancer Center in São Paulo indicates a 7.6% annual growth in colorectal cancer patients under 50 between 2000 and 2023, representing a five-fold increase. Cases in patients over 50 grew even faster at 8.1% annually.
Marc Gunter, a professor of cancer epidemiology at Imperial College London, suggests this pattern mirrors what occurred in wealthier nations as diets became more Westernized and lifestyles more sedentary. He argued that Latin American countries are likely following the same trajectory. However, Berrington de Gonzalez highlighted the need for stronger cancer registration systems in countries like Brazil and Mexico, where obesity rates have also climbed sharply.
Another 2025 analysis involving 42 countries compared data from 2003 to 2017 across two age groups: 20 to 49 years and 50 years and older. The study identified six cancers—thyroid, breast, colorectal, kidney, uterine, and leukemia—that rose among younger adults in most nations. Notably, colorectal cancer was unique; in about a third of the countries studied, it increased faster in younger adults than in older ones, even as rates declined in the older demographic.
Researchers are also exploring whether better detection explains the statistics. A US study on pancreatic cancer in adults aged 15 to 39 found that rising incidence was driven almost entirely by early-stage tumors, with death rates remaining stable. This suggests increased screening and awareness rather than a true rise in disease. Conversely, colorectal cancer data from the US indicates increases in advanced-stage diagnoses as well, pointing to a genuine rise in cases.
Obesity is a well-established risk factor for at least 13 cancers, according to the WHO’s International Agency for Research on Cancer (IARC). A 2021 review found that young adults with obesity were nearly twice as likely to develop colorectal cancer before age 50. Obesity rates have doubled among adults and quadrupled among adolescents since the 1990s. Dietary factors also play a critical role: processed meat is classified as carcinogenic, alcohol is a known risk factor, and fiber from vegetables, whole grains, and pulses can lower cancer risk.
While some speculate that ultra-processed foods and microplastics contribute to the trend, Gunter described the evidence as inconclusive, calling much of the discussion “hype.” Berrington de Gonzalez agreed, stating that while diets have changed, their specific role requires further study.
Experts stress that public health policy must address societal structures built around convenience foods and sedentary work, rather than placing blame on individuals. Nonetheless, Gunter recommended that young people maintain a healthy weight, increase physical activity, consume more fiber, and reduce processed meat intake. For a 30-year-old reader, Berrington de Gonzalez offered reassurance: despite the upward trend, cancer at a young age remains relatively rare.
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