Incidence of CNS tumors in Appalachian children.

Determine whether the risk of astrocytomas in Appalachian children is higher than the national average. We compared the incidence of pediatric brain tumors in Appalachia versus non-Appalachia regions, covering years 2000-2011. The North American Association of Central Cancer Registries (NAACCR) collects population-based data from 55 cancer registries throughout U.S. and Canada. All invasive primary (i.e. non-metastatic tumors), with age at diagnosis 0-19 years old, were included. Nearly 27,000 and 2200 central nervous system (CNS) tumors from non-Appalachia and Appalachia, respectively comprise the cohorts. Age-adjusted incidence rates of each main brain tumor subtype were compared. The incidence rate of pediatric CNS tumors was 8% higher in Appalachia, 3.31 [95% CI 3.17-3.45] versus non-Appalachia, 3.06, [95% CI 3.02-3.09] for the years 2001-2011, all rates are per 100,000 population. Astrocytomas accounted for the majority of this difference, with the rate being 16% higher in Appalachian children, 1.77, [95% CI 1.67-1.87] versus non-Appalachian children, 1.52, [95% CI 1.50-1.55]. Among astrocytomas, World Health Organization (WHO) grade I astrocytomas were 41% higher in Appalachia, 0.63 [95% CI 0.56-0.70] versus non-Appalachia 0.44 [95% CI 0.43-0.46] for the years 2004-2011. This is the first study to demonstrate that Appalachian children are at greater risk of CNS neoplasms, and that much of this difference is in WHO grade I astrocytomas, 41% more common. The cause of this increased incidence is unknown and we discuss the importance of this in relation to genetic and environmental findings in Appalachia.