Trends in paediatric central nervous system tumour incidence by global region from 1988 to 2012

Abstract

Abstract Background Central nervous system (CNS) tumours comprise 20% of childhood cancers worldwide. Whether childhood CNS tumour incidence has increased over time across geographic regions remains to be explored. Methods We identified CNS cancers in the Cancer in Five Continents (CI5) data and estimated age standardized incidence rates (ASRs; cases/million children) and 95% confidence intervals (95% CI), male-to-female incidence rate ratios (IRR; 95% CI) and average annual percent change in incidence (AAPC; 95% CI) by geographic region for children aged 0–19 years where data were available using Poisson regression and generalized estimating equations (GEE). Cancers included: astrocytic tumours, medulloblastoma, ependymal, oligodendroglial and mixed glioma, glioma of uncertain origin, and other embryonal tumours. Geographic regions were defined using the United Nations geoscheme. Results There were 56 468 CNS cancers included in the study. ASRs were highest for astrocytic tumours globally in 2012 (ASR: 5.83; 95% CI: 5.68–5.99). Globally, all cancers exhibited a male excess in incidence. Regionally, only medulloblastoma had a consistently elevated male-to-female IRR at 1.4–2.2. Globally, incidence decreased for astrocytic tumours in GEE models (AAPC: −1.66; 95% CI: −3.04 to −0.26) and increased for medulloblastoma (AAPC 0.66; 95% CI: 0.19–1.14), ependymal tumours (AAPC: 1.49; 95% CI: 1.49; 95%: 0.69–2.30), glioma of uncertain origin (AAPC: 4.76; 95% CI: 1.17–1.14) and other embryonal tumours (AAPC: 3.58; 95% CI: 2.03–5.15). Regional variation in incidence trends was observed. Countries moving from lower to higher Human Development Index (HDI) over time did not appear to drive observed incidence trends. Conclusions Epidemiologic and molecular studies on underlying mechanisms for changes in the global incidence of CNS tumours are necessary.