Primary CNS germ cell tumors: Current epidemiology and update on treatment

Primary central nervous system (CNS) germ cell tumors (GCTs) are a heterogeneous group of lesions that account for 0.5 % of all primary brain and CNS tumors, occurring at an incidence rate of 0.10 per 100,000 person-years in the United States with approximately 90 % of the cases before the age of 20 years. Primary CNS GCTs demonstrate a remarkable difference in incidence based on gender and location within the brain with males having a 15:1 incidence in the pineal region while the gender incidence is nearly 1:1 in the rest of the brain. Also, historically the incidence was noted to be significantly higher in Japan and East Asia, but recent studies in Japan demonstrate similar incidence as in the United States. They are broadly classified as germinomas and non-germinomatous germ cell tumors (NGGCTs) based on clinicopathologic features. Germinomas are sensitive to treatment with radiotherapy and chemotherapy with high cure rates and carry an excellent prognosis, while NGGCTs display various forms of differentiation, have a poorer prognosis and are refractory to therapy. Standard management of CNS GTCs remains unsettled and ongoing research aims to achieve best possible survival rates and post-treatment quality of life by reduction in treatment intensity.