Cerebellar anaplastic astrocytoma in adult patients: 15 consecutive cases from a single institution and literature review

Abstract

Adult cerebellar anaplastic astrocytomas (cAA) are rare entities and their clinical and genetic characteristics remain to be fully described. Previously, malignant gliomas of the cerebellum were combined and reviewed together (cAA and cerebellar glioblastomas (cGB), that could have possibly affected overall results. We analyzed characteristics of 15 adult patients with cAA and compared them to a series of 45 patients with a supratentorial AA (sAA). The mean age at cAA diagnosis was 39.3 years (range 19-72). A history of neurofibromatosis type I was noted in 1 patient (6.7%). An IDH-1 mutation was identified in 6/15 cases and a methylated MGMT promoter in 5/15 cases. Patients in study and control groups were matched in age, sex and IDH-1 mutation status. Patients in a study group tended to have a more frequent multifocal presentation at diagnosis (13% vs. 4.4%) and were associated with longer overall survival (50 vs. 36.5 months), but the difference did not reach statistical significance. In both cAA and supratentorial AA groups presence of the IDH-1 mutation remains a positive predictor for the survival. The present study suggests that adult cAA constitute a group of gliomas with relatively high rate of IDH-1 mutations and prognosis similar to supratentorial AA. The present study is the first to systematically compare cAA and supratentorial AA with respect to their genetic characteristics and suggests that both groups shows a similar survival prognosis.