Hodgkin lymphoma (HL) is a relatively rare but curable hematologic malignancy characterized by the presence of Reed-Sternberg cells. It displays a bimodal age distribution, with an initial peak in adolescents and young adults and a second in individuals over 55 years. Early-onset Hodgkin lymphoma (EOHL), defined here as diagnosis at or before 39 years of age, accounts for a substantial share of global HL cases and is of particular epidemiological interest due to its occurrence in younger, otherwise healthy individuals, potentially leading to significant loss of quality-adjusted life years. Understanding its distribution may elucidate potential hereditary, infectious, and environmental contributors and reveal global disparities in cancer detection and care.

To analyze the global incidence of EOHL (ages 0-39) in 2022, stratified by country, continent, United Nations (UN) region, Human Development Index (HDI), and World Bank income classification, and to explore potential genetic, environmental, and socioeconomic factors in specific populations.

This is a descriptive epidemiological study based on data extracted from the Cancer Today platform of the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO). Incidence estimates for HL in individuals aged 0-39 years in 2022 were analyzed. The age-standardized rate (ASR, per 100,000 inhabitants) was used for comparisons. Stratifications were made by geographic (country, continent, and UN region), socioeconomic (HDI), and economic (World Bank income classification) parameters to identify patterns and disparities.

A total of 38,970 new cases were identified globally in 2022, with an ASR of 0.74 per 100,000. The highest national ASRs were observed in Italy (3.6), Portugal (3.3), Iceland (3.2), Slovakia (3.2), and Belgium (3.0). Thirteen countries, mostly low-income, reported zero cases. Europe had the highest continental ASR (2.2), followed by North America (2.1), Oceania (1.5), Latin America (1.0), Africa (0.60), and Asia (0.47). Among UN regions, the highest rates occurred in Southern, Northern, and Western Europe (2.7, 2.3, and 2.2, respectively), whereas the lowest were recorded in Western Africa (0.36), Middle Africa (0.25), and Eastern Asia (0.21). Micronesia and Polynesia reported no cases. HDI stratification revealed a gradient: very high HDI countries exhibited an ASR of 1.8, considerably higher than high (0.61), medium (0.48), and low HDI nations (0.48). Similarly, high-income countries showed the highest incidence (1.9), followed by upper-middle-, lower-middle-, and low-income nations. Brazil reported 1,419 cases, with an ASR of 0.98, nearly matching the Latin American average.

The incidence of EOHL varies widely across regions and socioeconomic contexts. Higher ASRs in developed nations may be attributed to enhanced diagnostic capacity, effective health registries, and potential environmental or genetic risk factors. In contrast, underdiagnosis, limited access to medical care, and competing health priorities may contribute to underreporting in low-income and low HDI countries. These findings underscore the urgent need for expanded cancer surveillance systems, investments in diagnostic infrastructure, and further research into the multifactorial causes of EOHL. Addressing these gaps is fundamental to improving early detection, optimizing treatment strategies, and reducing global health disparities in lymphoma care.