American Brain Tumor Association Adolescent and Young Adult Primary Brain and Central Nervous System Tumors Diagnosed in the United States in 2008-2012.

Brain and central nervous system (CNS) tumors found in adolescents and young adults (AYA) are a distinct group of tumors that pose challenges not only to treatment but also to reporting. Overall, cancer that occurs in this age group is biologically distinct from those that occur in both younger and older age groups1,2 posing significant challenges for clinicians. The most commonly diagnosed histologies in AYA vary from those in both children age (0-14 years), and older adults (40+ years).3,4 Prognosis and expected survival also varies between younger and older adults, with those who are diagnosed with brain and CNS tumors at younger ages having significantly longer survival. Despite this survival advantage, recent analyses have reported that while cancer survival has been improving overall, AYA have not experienced these same increases in survival and in some cases may have worse survival than those cancers diagnosed in persons over age 40 years.5 This report provides an in depth analyses of the epidemiology of brain and CNS tumors in adolescents and young adults in the United States (US), and is the first report to provide histology-specific statistics in this population for both malignant and non-malignant brain and other CNS tumors. In 2006, the National Institutes of Health, the National Cancer Institute (NCI) and the LiveStrong Young Adult Alliance conducted a Progress Review Group to investigate AYA Oncology entitled Research and care imperatives for adolescents and young adults with cancer: A Report of the Adolescent and Young Adult Oncology Progress Review Group. This group established the standard age range for the AYA group as 15-39 years. This is the age range used by the Surveillance Epidemiology and End Results (SEER) program of the NCI, as well as in the 2015 CBTRUS Statistical Report.3,6 Brain tumors and other CNS tumors are less common in AYA than in older adults, but they have a higher incidence than brain tumors in children (age 0-14 years).3 Non-malignant tumors are significantly more common in AYA than children (Average annual age adjusted incidence in age 15-39 years: 6.17 per 100,000; age 0-14 years: 0.79 per 100,000), while malignant tumors are slightly more common in those age 0-14 years (Average annual age adjusted incidence in 15-39 years old: 3.26 per 100,000; 0-14 years old: 3.73 per 100,000). While a rare cancer overall, brain and CNS tumors are among the most common cancers occurring in this age group (4.4% of all cancers in those age 15-39 years as compared to 32.4% in children age 0-14 years, and 2.2% of cancers in adults age 40+ years).3,4,7 Malignant brain and CNS tumors are the 11th most common cancer and the 3rd most common cause of cancer death7,8 in the AYA population. Incidence rates of brain tumors overall as well as specific histologies vary significantly by age. It is, therefore, important to provide an accurate statistical assessment of brain and other CNS tumors in the adolescent and young adult population to better understand their impact on the US population and to serve as a reference for afflicted individuals, for researchers investigating new therapies and for clinicians treating patients.