LAUSR

Abstract BACKGROUND/PURPOSE One of the most problematic issues Japan has is a declining birthrate resulting in an aging society. There are some reports on the trends of incidence in brain tumors in the elderly, whereas few reports on those in the children. The aim of this study is to investigate the trends of incidence in childhood primary brain tumors. METHODS The population of children aged <15 years was available from Kumamoto Prefecture’s annual census between 1990 and 2017. During the period 301 childhood primary brain tumors (124 gliomas, including astrocytic tumors and ependymomas, 35 embryonal tumors, 34 germ cell tumors, 22 craniopharyngioma, and 86 others) were registered with the Kumamoto Brain Tumor Data Bank, and investigated. RESULTS The average of the annual incidence rate per 100,000 child populations was 3.90 for total brain tumors, 1.63 for gliomas, 0.44 for embryonal tumors, 0.42 for germ cell tumors, 0.26 for craniopharyngioma, and 1.15 for others. Divided into the first half from 1990 to 2003 and the second half from 2004 to 2017, there was no significant difference in the incidence of brain tumors aged <15 years between the two periods. However, the average of the annual incidence rate/100,000 child populations was 3.02 in the first half, while significantly increased in the second half of 4.78 (p=0.00075, t-test). DISCUSSION & CONCLUSIONS The average number of children aged <15 years in Kumamoto Prefecture was 31,2737.9 from 1990 to 2003, while decreased remarkably to 251460.2 from 2004 to 2017. A decrease in the number of children may affect increasing the incidence rate of pediatric brain tumors.