MYCN amplification predicts poor outcome of patients with LIN28 negative supratentorial primitive neuroectodermal tumors of the central nervous system (CNS-PNET)

Primitive neuroectodermal tumors of the central nervous system (CNS-PNET) are rare neoplasms. Whereas ependymoblastomas frequently carry chr. 19q13.41 amplifications, express the stem cell marker LIN28 and show aggressive clinical behaviour, the biology of other supratentorial CNS-PNETs remains so far poorly understood and prognostic genetic alterations suitable for molecular risk stratification are to date not defined. In order to identify possible molecular markers we performed multiplex ligation-dependent probe amplification (MLPA) and molecular inversion probe (MIP) analysis on DNA samples of 25 supratentorial CNS-PNET. Patients with tumors harbouring 2 p gain or MYCN amplification showed a shorter overall survival (OS) (p = 0.0029 and p = 0.0021, respectively). These parameters were independent from the presence of metastases, which represented a clinical factor associated to shorter OS (p = 0.0112) in this series. The identification of these molecular prognostic markers associated to patients' outcome may represent a significant step towards an improved stratification and risk-adapted therapy for patients suffering from CNS-PNETs.