DOI 10.1007/s00401-014-1325-8 REVIEW Epigenetic dysregulation: a novel pathway of oncogenesis in pediatric brain tumors

© The Author(s) 2014. This article is published with open access at Springerlink.com Current challenges in subgroups of high‑grade pediatric brain tumors According to the most recent reports published in 2014, one in every 285 children will be diagnosed with can-cer before the age of 20 years [73]. Overall survival has improved substantially over the last three decades for spe-cific cancer types, mainly childhood leukemia, partly based on better stratification of patients using molecular tools. In contrast, a subset of tumors remains incurable today and includes subgroups of brain tumors, a leading cause of cancer-related morbidity and mortality in the pediatric years. Several impediments to effective treatment exist and hamper the design and outcome of needed novel clinical trials. Diagnosis still relies mainly on standard pathology that characterizes tumors according to the World Health Organization (WHO) classification. Tumors are classified according to their presumed cell of origin and then are further divided into distinct histological grades, ranging from WHO grade I to WHO grade IV based on cytologic and histologic features (Fig. 1). Moreover, these tumors are often studied and treated as if they were analogous to adult tumors. However, pediatric brain tumors of most patho-logical types appear to harbor unique molecular alterations compared to these very same tumors occurring in the adult years, although under the microscope they are indistin