Clinicopathological features and molecular analysis of primary glioblastomas in Moroccan patients

Glioblastoma is the most frequent and most aggressive primary brain tumor. Primary and secondary glioblastomas develop through different genetic pathways. The aim of this study was to determinate the genetic and clinical features of primary glioblastoma in Moroccan patients. The blood and tumor samples were obtained from a group of 34 Moroccan patients affected with primary glioblastoma. The tumors were investigated for TP53, IDH1, and IDH2 mutations using PCR sequencing analysis. Clinicopathological data showed that the mean age at diagnosis of patients was 50.06 years, the sex ratio was 11 F/23 M, and the median of Karnofsky performance score was 60. About 18 % of patients were initially treated by total tumor resection, 41 % by subtotal, and 38 % by partial resection, but biopsy was performed for a single patient (3 %). Twenty-five patients (74 %) received radiotherapy. In addition, the median survival of the all patients was 13 months following diagnosis. There was a significant impact of higher Karnofsky performance score (KPS) (≥80) on overall survival, p-log-rank test = 0.0002, whereas other parameters did not show any significant differences. The molecular analysis revealed TP53 mutations in 3/34 (8.82 %) cases; R273H, R306X, and Q136X. However, none of the analyzed samples contained the R132-IDH1 or R172-IDH2 mutations. These results showed the absence of IDH1 mutation in primary glioblastoma, confirming that this mutation is a hallmark of secondary glioblastoma. It can be used to distinguish primary from secondary glioblastomas. We found also that higher KPS was a significantly favorable factor in patients with primary glioblastoma.