Pediatric brain tumors (PYBT) account for 20 % of all childhood tumors, are the leading cause of disease-related death in children in the United States and have increased by 2.5 % annually over the last decade [1], [2]. PYBT incidence is highest in late teens (15–19 years old), who are diagnosed at a rate of 7.31 cases per 100,000, followed by infants (6.31 cases per 100,000) [3]. Although survival has increased in the last decade, side effects from surgery, chemotherapy, and radiation can be long term and severe [4], [5], [6].

Preliminary studies have found that the Appalachian region of Kentucky, a predominately rural region encompassing 54 of Kentucky’s 120 counties [7], has some of the highest incidence rates of PYBT in the United States (US) [8]. The greater Appalachian region, which encompasses 420 counties across 13 states, has notably higher poverty rates, chronic disease, and cervical and lung cancer incidence [9]. In Kentucky, this region also has notably high rates of smoking and obesity. In a study using data from the Central Brain Tumor Registry of the United States, Ostrom et al. noted a 6 % higher incidence of malignant PYBT in Appalachian children compared to non-Appalachian children (0–14 years), Survival was also lower in the Appalachian region [10]. In a study assessing geospatial patterns of PYBT in Kentucky using data from the North American Association of Central Cancer Registries (NAACCR), Huang et al. noted that the Appalachian region had an 8 % higher rate of all brain tumors compared to the non-Appalachian regions of the United States, and 41 % higher for low-grade astrocytomas [8].

Despite such previous reporting of geographic areas with elevated PYBT [8], [10], risk factors have been challenging to identify. Although it is a leading cause of cancer-related deaths in children, diagnosis of PYBT is still relatively uncommon [11]. Further complicating population-based assessments of PYBT incidence are unknown latency, the historically inconsistent definitions of PYBT types among cancer registries, and the heterogeneity of PYBT—over 100 subtypes have been identified to date [2], [10], [12]. No lifestyle or geographic factors have been identified that are generally accepted to modify risk for PYBT [13]; however, emergent research exploring the impact of prenatal exposures found that pregnant women who live within one mile of an industrial site actively emitting carcinogenic materials had children with an increased risk of PYBT [14]. In an analysis exploring traffic-related hazardous air pollutants (1,3-butadiene, benzene, diesel particulate matter [DPM]) in Texas (2001–2009), researchers observed that census tracts with elevated concentrations of 1,3-butadiene had higher incidence rates of astrocytomas and medulloblastomas compared to low concentration areas [15]. In a recent meta-analysis, Vinson et al. found that paternal exposure to pesticides (before and after birth) was associated with increased risk of PYBT [16]. There is also evidence that ionizing radiation increases risk for PYBT, however, children are rarely exposed to radiation [2]. specifically subsets nitrosamines and nitrosamides, could be a risk factor for PYBT, however to study nitrosamine exposures is notoriously difficult due to its ubiquity in the environment [17]. Nitrosamines, formed by a reaction between nitrates or nitrates and specific amines, are most commonly encountered in processed meats, alcoholic beverages, cosmetics, cigarette smoke, certain medications, and can be formed in the mouth or stomach if food contains nitrosamine precursors and has been classified as 2b, or “probable carcinogens” by the IARC [18], [19], [20].

Our primary aim in this study was to characterize PYBT risk in Kentucky using choropleth maps (i.e., maps that shows values by shaded areas) and spatial statistical methods. As much of Kentucky’s economy has, historically, varied regionally (e.g., coal mining in the east and industrial agriculture in the west), a secondary aim was to compare the results to maps displaying industries and environmental hazards that might feasibly be associated with PYBT risk.