Background:The radiochemotherapy regimen concomitantly employing temozolomide (TMZ) chemotherapy and radiotherapy (RT) 4 weeks after surgery,followed by 6 cycles of TMZ is a common treatment for glioblastoma (GBM).However,its median overall survival (OS) is only 14.6 months.This study was to explore the effectiveness and safety of early TMZ chemotherapy between surgery and chemoradiotherapy plus the standard concomitant radiochemotherapy regimen.Methods:A randomized,parallel group,open-label study of 99 newly diagnosed GBM patients was conducted at 1 0 independent Chinese neurosurgical departments from June 2008 to June 2012.Patients were treated with concomitant radiochemotherapy regimen plus early postsurgical temozolomide (early TMZ group) or standard concomitant radiochemotherapy regimen (control group).Overall response was assessed based on objective tumor assessments,administration ofcorticosteroid and neurological status test.Hematological,biochemical,laboratory,adverse event (AE),and neurological condition were measured for 24 months of follow-up.The primary efficacy endpoint of this study was overall survival (OS).The secondary endpoint was progression free survival (PFS).Results:The median OS time in the early TMZ group was 17.6 months,compared with 13.2 months in the control group (log-rank test P =0.021).In addition,the OS rate in the early TMZ group was higher at 6,12,and 18 months than in the control group,respectively (P ＜0.05).The median PFS time was 8.7 months in the early TMZ group and 10.4 months in the control group (log-rank test P =0.695).AEs occurred in 29 (55.8％) and 31(73.8％) patients respectively in early and control groups,including nausea (15.4％ vs.33.3％),vomiting (7.7％ vs.28.6％),fever (7.7％ vs.11.9％),and headache (3.8％ vs.23.8％).Only 30.8％ and 33.3％ were drug-related,respectively.Conclusions:Addition of TMZ chemotherapy in the early break of the standard concomitant radiochemotherapy regimen was well tolerated and significantly improved the OS of the GBM patients.compared with standard concomitant radiochemotherapy regimen.However,a larger randomized trial is warranted to verify these results.