Stemming the Rising Tide of Early-Onset Cancers: Research Gaps and Public Health Actions

Early-onset cancers (EOCs), typically defined as cancers diagnosed before age 50, are rising across multiple organ sites and populations globally. EOCs often exhibit more aggressive biology than later-onset cancers and contribute disproportionately to premature mortality and morbidity. A large sex disparity exists, with two-thirds of EOCs diagnosed in women. While EOC incidence is increasing broadly, patterns vary by geography, income, and race/ethnicity, offering clues about the role of health behaviors, environmental exposures, preventive care, and broader social and economic contexts. Gaps remain in our etiologic understanding of EOCs, including the contribution of modifiable environmental factors. Addressing this burden will require coordinated research using novel epidemiologic, intervention, and implementation science approaches, alongside policy action. We provide an overview of EOC trends, examine key methodological considerations, review established and suspected risk factors, and highlight opportunities to strengthen prevention and early detection, with a focus on US and relevant global considerations.