Comparative analyses of erythroblast transformation specific-1 related gene expression before and after neoadjuvant bevacizumab therapy for newly diagnosed glioblastoma

The aim of the present study was to investigate the expression of erythroblast transformation specific-1 related gene (ERG) in patients with glioblastoma (GB) before and after bevacizumab (Bev) therapy as a predictive and prognostic biomarker. The present study used 58 GB tissues from 29 patients in 3 settings. Sixteen tumors were removed after neoadjuvant Bev administration (neoBev) and 13 represented newly diagnosed GB without previous Bev treatment (naïve Bev). Another 29 specimens of recurrence were obtained from salvage surgery or autopsy. Immunohistochemical analysis showed both vessel density (VD) and ERG score were decreased in neoBev compared with naïve Bev. VD and ERG score tended to be lower at recurrence than at initial surgery (P=0.0026 and P=0.1338, respectively). In the naïve Bev and neoBev cohorts, overall survival (OS) with high and low expressions of ERG was comparable (P=0.7516 and P=0.3862, respectively). High expression of ERG in GB with naïveBev was significantly reduced with Bev, but not changed in refractoriness. Stratification of ERG expression levels might provide a useful predictive biomarker for GB treated with Bev.