Progress against non-Hodgkin's lymphoma in children and young adolescents in the Netherlands since 1990: Stable incidence, improved survival and lower mortality

Background: With epidemiologic analyses of population-based trends in incidence and outcomes, we ascertained progress against non-Hodgkin's lymphoma (NHL) in children and young adolescents in the Netherlands since 1990. Methods: Tumour characteristics were extracted from the Netherlands Cancer Registry for patients aged <18 years at diagnosis, between 1990 and 2015. Mortality data for 1980–2016 were derived from Statistics Netherlands. NHL subtypes comprised lymphoblastic lymphoma (LBL), Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) and anaplastic large cell lymphoma (ALCL). Time trends in incidence and mortality rates and 5-year overall survival (OS) rates were evaluated by average annual percentage change (AAPC) analyses and parametric survival models, respectively. Results: Overall incidence of NHL remained stable at 11 per million person-years (AAPC -0.2%, p = 0.68), with a marked decrease among children of 5–9 years (AAPC -2.6%, p < 0.01), especially among those with BL. Treatment regimens comprised less radiotherapy over time, especially for LBL and BL. Since 2004, most 15–17-year-old patients with NHL have been treated at a paediatric oncology centre. Five-year OS improved from 71% in 1990–94 to 87% in 2010–15 (p < 0.01), the most gain has been achieved in patients with DLBCL and ALCL from 60% and 73%, respectively, to both 90%. Population-based mortality from NHL decreased significantly towards 1.4 per million person-years (AAPC -4.2%, p < 0.01). Conclusions: This population-based epidemiological study exhibited significant progress against childhood and young adolescent NHL in the Netherlands since 1990, before the advent of a national paediatric oncologic centre in 2018: incidence decreased among children of 5–9 years, survival improved, and mortality steadily decreased over time.