Global variation in young adult central nervous system tumor incidence by region, age, and sex from 1988 to 2012.

BACKGROUND:Central nervous system (CNS) tumors result in tremendous morbidity and mortality. Incidence of CNS tumors in young adults is less studied. It is unknown how young adult CNS tumor incidence has changed globally in recent decades. METHODS:We used Cancer Incidence in Five Continents (CI5) data (1988-2012) to estimate incidence rates (IR), average annual percent change in incidence (AAPC; 95% confidence intervals [95% CI]), and male-to-female incidence rate ratios (IRR; 95% CI) by six histologies and age at diagnosis (20-29years, 30-39years). Tumors were classified as astrocytic, medulloblastoma, ependymal, oligodendroglial, meninges, and other embryonal. Geographic regions were defined using the United Nations Statistics Division geoscheme. RESULTS:There were 78,240 CNS tumor cases included. 20-29-year-old (yo) rates were lower than 30-39 yo in most regions for astrocytic, oligodendroglial and ependymal tumors. Globally, astrocytic tumor incidence decreased (20-29 yo AAPC: - 0.70; 95% CI: - 1.32, - 0.08) while incidence increased for oligodendroglial (20-29 yo AAPC: 3.03; 95% CI: 1.57-4.51; 30-39 yo AAPC: 2.67; 95% CI: 0.79-4.58), ependymal (20-29 yo AAPC: 1.16; 95% CI: 0.31-2.03; 30-39 yo AAPC: 2.29; 95% CI: 1.14-3.46), medulloblastoma (30-39 yo AAPC: 0.6; 95% CI: 0.04-1.24) and tumors of the meninges (20-29 yo AAPC: 1.55; 95% CI: 0.04-3.07). There was a 20-40% male incidence excess in all histologies except for meninge tumors (30-39 yo IRR: 0.71; 95% CI: 0.61, 0.84). CONCLUSIONS:Incidence of oligodendroglial and ependymal tumors increased globally in 20-39 yo suggesting better diagnoses or changes in risk factors. Males had a higher incidence of CNS tumors for most tumors studied and in most regions.