Trends in incidence and five-year relative survival analysis of classical Hodgkin lymphoma in children, adolescents, and young adults (ages <20): A population-based study using National Childhood Cancer Registry (NCCR) data (2001–2021).

e13778 Background: Classical Hodgkin lymphoma (cHL) is a significant malignancy affecting pediatric populations, with implications for public health and clinical practice. This study evaluates trends in incidence and 5-year relative survival rates using data from the National Cancer Registries (NCCR), covering 75% of U.S. children, adolescents, and young adults. Methods: This population-based retrospective cohort study analyzed age-adjusted incidence rates (2001–2021) and 5-year relative survival rates (2014–2020) of cHL in patients aged < 20 years. Data were obtained from the NCCR, with cases stratified by sex, race/ethnicity, and age. Annual Percent Change (APC) and Average Annual Percent Change (AAPC) were calculated using Joinpoint Regression Program version 4.9.1.0, applying a log-linear model. Statistical significance was assessed at p < 0.05. Survival analysis used Kaplan-Meier methods, with 95% confidence intervals (CIs) estimated. Results: From 2001 to 2021, the overall age-adjusted incidence rate of cHL in pediatric populations showed no significant change for both sexes (APC: -0.1%, 95% CI: -0.5 to 0.2, p = 0.69). Sex-specific trends were similarly non-significant for females (APC: -0.1%, 95% CI: -0.6 to 0.4, p = 0.67) and males (APC: -0.2%, 95% CI: -0.7 to 0.3, p = 0.47). Recent trends (2017–2021) also showed non-significant changes for both sexes (AAPC: -0.1%, 95% CI: -0.5 to 0.2, p = 0.68). Survival analysis revealed an overall 5-year (2014-2020) relative survival rate of 98.6% (95% CI: 97.9–99) for all races combined. Non-Hispanic White patients had a survival rate of 98.6% (95% CI: 97.9–99), while non-Hispanic Black patients had a slightly lower survival of 97.3% (95% CI: 95–98.5). No significant differences in survival rates were observed between females (99%, 95% CI: 98.2–99.5) and males (98.1%, 95% CI: 97–98.8, p = 0.34). Age stratification indicated a 5-year survival rate of 100% in children aged 5–9 years, with a slightly lower rate of 98.3% (95% CI: 97.7–98.8) in adolescents aged 15–19 years. Survival disparities by race/ethnicity and age, while not statistically significant, highlight the need for further investigation. Conclusions: Classical Hodgkin lymphoma incidence rates in pediatric populations have remained stable over two decades, with no significant changes across sexes or recent years. The five-year relative survival rates for cHL in patients under 20 years remain remarkably high across sex, race/ethnicity, and age groups. These findings highlighted the efficacy of current treatment approaches and highlight the need to address disparities in specific racial/ethnic subgroups to ensure equitable outcomes.