Epidemiologic trends for pediatric Hodgkin and non-Hodgkin lymphomas: a U.S. population-based study

Pediatric Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are distinct from adult forms and occur less frequently. We identified 7,871 children and 226,211 adults with lymphoma from the Surveillance, Epidemiology, and End Results database from 1975 to 2018. The age-adjusted incidence rate for pediatric lymphoma was 24.5 per million persons (95% CI: 24.0-25.1), comprising 13.0 per million (95% CI: 12.6-13.4) for HL and 11.5 per million (95% CI: 11.1-11.9) for NHL. In comparison to adult lymphoma, pediatric lymphoma showed no significant changes in incidence from 1975 to 2002 (annual percentage change, APC = -0.12 ± 0.19, P = 0.53), but displayed an observable increase after 2003 (APC = + 1.31 ± 0.45, P = 0.006). Among pediatric cases, the 5-year limited-duration prevalence rate increased from 0.00691% in 1996 to > 0.009% in recent years, and the 20-year rate rose from 0.0109% in 1996 to 0.0148% in 2018. In alignment with the observed decrease in incidence over the recent decade, the prevalence of adult lymphoma exhibited a more gradual growth post-2007. Among adult patients, the age-adjusted mortality rate demonstrated an initial increase in the periods 1975-1977 (APC = + 41.06 ± 6.23, P < 0.001), 1977-1980 (APC = + 9.83 ± 4.27, P = 0.036), 1980-1989 (APC = + 5.24 ± 0.36, P < 0.001), and 1989-1994 (APC = + 2.27 ± 0.86, P = 0.014), followed by a subsequent decrease after 1994 (APC= -0.49 ± 0.05, P < 0.001). In contrast, the mortality rates of pediatric lymphoma exhibited a consistent decrease over the past four decades (1975-2018: APC= -3.12 ± 0.29, P < 0.001), resulting in an overall age-adjusted mortality rate of 2.92 (95% CI: 2.73-3.11).