ABSTRACT
BACKGROUND: Glioblastoma multiforme with an oligodendroglial component (GBMO) has been recognized in the World Health Organization classification-however, the diagnostic criteria, molecular biology, and clinical outcome of primary GBMO remain unclear. Our aim was to investigate whether primary GBMO is a distinct clinicopathological subgroup of GBM and to determine the relative frequency of prognostic markers such as loss of heterozygosity (LOH) on 1p and/or 19q, O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation, and isocitrate dehydrogenase 1 (IDH1) mutation. METHODS: We examined 288 cases of primary GBM and assessed the molecular markers in 57 GBMO and 50 cases of other primary GBM, correlating the data with clinical parameters and outcome. RESULTS: GBMO comprised 21.5% of our GBM specimens and showed significantly longer survival compared with our other GBM (12 mo vs 5.8 mo, P = .006); there was also a strong correlation with younger age at diagnosis (56.4 y vs 60.6 y, P = .005). Singular LOH of 19q (P = .04) conferred a 1.9-fold increased hazard of shorter survival. There was no difference in the frequencies of 1p or 19q deletion, MGMT promoter methylation, or IDH1 mutation (P = .8, P = 1.0, P = 1.0, respectively). CONCLUSIONS: Primary GBMO is a subgroup of GBM associated with longer survival and a younger age group but shows no difference in the frequency of LOH of 1p/19q, MGMT, and IDH1 mutation compared with other primary GBM.
Subject(s)
DNA Methylation , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Glioblastoma/genetics , Isocitrate Dehydrogenase/genetics , Loss of Heterozygosity , Mutation/genetics , Oligodendroglioma/genetics , Tumor Suppressor Proteins/genetics , Adult , Aged , Aged, 80 and over , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Brain Neoplasms/mortality , Chromosomes, Human, Pair 1/genetics , Chromosomes, Human, Pair 19/genetics , Female , Follow-Up Studies , Glioblastoma/diagnosis , Glioblastoma/mortality , Humans , Male , Middle Aged , Neoplasm Staging , Oligodendroglioma/diagnosis , Oligodendroglioma/mortality , Prognosis , Promoter Regions, Genetic/genetics , Survival RateABSTRACT
Investigations of the effects of radiation on neuropsychological functions have revealed variable outcomes, ranging from no effect to severe cognitive impairment. However, many of the previous studies have relied on retrospective data or have been limited by methodological problems. In this study, prospective neuropsychological assessments were compared at baseline (after surgery and before radiotherapy) and within 4 months of completion of radiotherapy (except one case), to examine early-delayed effects of radiation on intellectual and cognitive functioning. Sixteen adult patients with either low- or high-grade brain tumours, 15 of whom were treated with radiotherapy, were compared with 8 control participants with nonmalignant brain tumours whom did not undergo radiotherapy. All participants had lesions situated mainly in the frontal lobes. All groups of patients had evidence of intellectual and cognitive impairment at baseline. The low- and high-grade brain tumour groups showed a differential pattern of performance following radiotherapy, with the low-grade tumour group's performance being more competent on all of the five main neuropsychological measures. Their pattern of improvement was very similar to that of the nonmalignant brain tumour group who had not undergone radiotherapy. The present study provides some preliminary information about the neuropsychological deficits associated with primary brain tumours, their severity, and the relationship between neuropsychological functioning and brain tumours and radiotherapy.
