Predictors of Improved Outcomes in the Management of Newly Diagnosed Glioblastoma Multiforme – Retrospective Review of a Single Centre Experience

Abstract

AIMS To assess the benefit of combining maximal resection, Gliadel wafer insertion, CCRT and 4 or more cycles of adjuvant TMZ. METHOD We retrospectively reviewed a cohort of 110 patients who had undergone neurosurgery followed by chemo-radiotherapy (CRT) 60 Gray in 30 fractions and had at least one cycle of adjuvant TMZ from 2007 to 2016. Minimum follow up period 5 years. RESULTS Patients who had maximal safe debulking plus Gliadel wafer insertion, median OS was 19.5 months (95% confidence interval 14-30) those without wafers median OS was 16 months (95% confidence interval 14 – 21), P=0.06; significant on cox regression modelling. (P-value 0.008). Those continuing to receive at least 4 cycles of adjuvant TMZ median OS improved by 10 months compared to those unable to complete 4 cycles (10 vs 20 months). On cox analysis the number of adjuvant cycles of TMZ significantly affects OS, P-value 0.0003. Of these significant predictors of OS when combined (n=12) median OS was 18 months. Compared to 16 months for those who did not receive Glidel wafers and could not complete 4 cycles of TMZ following CRT. OS log-rank test P-value 0.4 CONCLUSION We were not able to demonstrate a statistically significant improved OS for those undergoing wafer insertion and completing at least 4 cycles of TMZ. Data may be inconclusive due to the small numbers, we conclude standard of care should still remain maximal safe debulking followed by CCRT and TMZ.