Global prevalence trends and predictions of Hodgkin lymphoma from 1990 to 2021: age-period-cohort analysis and transnational inequality

Background: Hodgkin lymphoma (HL) is a highly curable malignancy with distinctive aetiological subtypes. Given recent therapeutic advances and demographic changes, an up-to-date assessment of the global HL burden is needed to inform evidence-based resource allocation and health policy planning. This study described the global prevalence trend of HL and analysed its age cohort and transnational inequality. Methods: We used data from the Global Burden of Disease 2021 study (204 countries/territories). We analysed age-standardised rates (ASRs) for incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) from 1990 to 2021. An autoregressive integrated moving average (ARIMA) model projected incidence trends to 2050. We used the age-period-cohort (APC) analysis to separate the effects of age, period, and cohort on HL burden. We assessed transnational inequality with the slope index of inequality and the concentration index. All estimates are reported with 95% uncertainty intervals (UI). Results: In 2021, an estimated 65,182 (95% UI = 53,167, 77,143) new HL cases occurred globally. Substantial geographic disparities were observed in ASRs per 100,000 population: prevalence 4.42 (95% UI = 3.75, 5.09), incidence 0.79 (95% UI = 0.64, 0.94), mortality 0.34 (95% UI = 0.25, 0.43), and DALYs 14.82 (95% UI = 10.43, 18.96). The global age-standardised incidence rate (ASIR) declined slightly (estimated annual percentage change = -1.10%; 95% confidence interval (CI) = -1.16, 1.05) from 1990 to 2021, yet absolute incident cases increased by 19.23% (95% CI = 14.14, 22.44), driven by population growth and ageing. We found that HL risk peaked among young (25-29 years) and older adults (65-69 years), with steady declines in relative risk across successive periods and birth cohorts. The burden consistently skewed towards males and high sociodemographic index (SDI) regions. Projections indicated a stable ASIR but a rising prevalence through 2050, alongside continued declines in mortality and DALY rates. Conclusions: We found that the global HL burden is characterised by stable ASIR but growing absolute case numbers, with a disproportionate impact on males and high-SDI countries. These trends, reflecting demographic shifts and therapeutic advances, underscore the necessity for robust diagnostic pathways and multidisciplinary, risk-adapted care models to manage the increasing population of HL survivors effectively.