When clinicians at The University of Kentucky Markey Cancer Center noticed what seemed to be a disproportionately high number of pediatric patients from Appalachia presenting with brain tumors, they turned to colleagues in the University of Kentucky College of Public Health to help them determine whether the rate of brain tumors is higher in Appalachian children than the national average. The investigation, the results of which appear in the Journal of Neuro-Oncology, is the first to demonstrate that Appalachian children are in fact at greater risk of central nervous system neoplasms, mostly in the form of astrocytomas.
To draw comparisons between Appalachian children and their peers outside the region, investigators 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 percent higher in Appalachia, 3.31 [95 percent CI 3.17–3.45] versus non–Appalachia, 3.06, [95 percent 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 percent higher in Appalachian children, 1.77, [95 percent CI 1.67–1.87] versus non-Appalachian children, 1.52, [95 percent CI 1.50–1.55]. Among astrocytomas, World Health Organization (WHO) grade I astrocytomas were 41 percent higher in Appalachia, 0.63 [95 percent CI 0.56–0.70] versus non-Appalachia 0.44 [95 percent 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 percent more common. The cause of this increased incidence is unknown and the investigators discuss the importance of this in relation to genetic and environmental findings in Appalachia.
Investigators on the study include Dr. Bin Huang, associate professor of cancer biostatistics, Dr. Quan Chen, radiation oncology specialist in cancer biostatistics, and Dr. Thomas C. Tucker, associate professor of epidemiology and director of the Kentucky Cancer Registry.
[Photo: Dr. Bin Huang]
[Photo: Dr. Quan Chen]
[Photo: Dr. Thomas C. Tucker]