Brain tumors; AT/RTs, ependymomas, and germ cell tumors

Abstract

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive pediatric tumors that frequently emerge during early childhood. The pathogenesis of AT/RTs results from the inactivation of the SMARCB1 and SMARCA4 genes and is partially linked to rhabdoid predisposition syndrome. Currently, treatment typically involves high-dose chemotherapy with peripheral blood stem cell rescue and local irradiation, with the aim of improving prognosis. Ependymomas are classified into two subgroups based on their molecular features and tumor location. Supratentorial ependymomas are classified as either ZFTA-fusion or YAP1-fusion, depending on fusion gene mutations, whereas infratentorial ependymomas are categorized as PFA or PFB based on DNA methylation status. The prognosis for ZFTA fusion and PFA is poor compared with that of their counterparts. Surgical resection is crucial for all types of ependymomas, while radiotherapy and/or chemotherapy are administered based on the extent of resection and molecular subgroup. Intracranial germ cell tumors (IGCTs) mainly occur in the neurohypophysis, pineal, and basal ganglia. These tumors are more prevalent in East Asia and pineal IGCTs primarily affect males, suggesting the involvement of genetic factors in disease pathogenesis. IGCTs are classified as germinomas or non-germinomatous germ cell tumors (NGGCTs). NGGCTSs are further divided into an intermediate-prognosis group, including immature teratomas, and a poor-prognosis group. The treatment strategy for IGCT varies according to the tumor group. Germinoma is highly curable with radio-chemotherapy but often leads to irreversible neurological deficits due to tumor invasion, making early diagnosis and effective treatment crucial. Although a standard treatment strategy for NGGCTs has not yet been established, the outcomes of ongoing clinical trials are eagerly awaited.