Frequency and clinical significance of chromosome 7 and 10 aneuploidies, amplification of the EGFR gene, deletion of PTEN and TP53 genes, and 1p/19q deficiency in a sample of adult patients diagnosed with glioblastoma from Southern Brazil

Abstract

Glioblastoma stands out as the most frequent central nervous system neoplasia, presenting a poor prognosis. The aim of this study was to verify the frequency and clinical significance of the aneuploidy of chromosomes 7 and 10, EGFR amplification, PTEN and TP53 deletions and 1p/19q deficiency in adult patients diagnosed with glioblastoma. The sample consisted of 40 patients treated from November 2011 to March 2015 at two major neurosurgery services from Southern Brazil. Molecular cytogenetic analyses of the tumor were performed through fluorescent in situ hybridization (FISH). The clinical features evaluated consisted of age, sex, tumor location, clinical symptoms, family history of cancer, type of resection and survival. The mean age of the patients was 59.3 years (ranged from 41 to 83). Most of them were males (70%). The median survival was 145 days. Chromosome 10 monosomy was detected in 52.5% of the patients, chromosome 7 polysomy in 50%, EGFR amplification in 42.5%, PTEN deletion in 35%, TP53 deletion in 22.5%, 1p deletion in 5% and 19q deletion in 7.5%. Age was shown to be a prognostic factor, and patients with lower age presented higher survival (p = 0.042). TP53 and PTEN deletions had a negative impact on survival (p = 0.011 and p = 0.037, respectively). Our data suggest that TP53 and PTEN deletions may be associated with a poorer prognosis. These findings may have importance over prognosis determination and choice of the therapy to be administered.

Keywords: 1p19q codeletion; EGFR; FISH; Glioblastoma; PTEN; Survival; TP53.