Ncmp-10. dexamethasone: a tool and a problem in glioblastoma management

Glioblastoma (GBM) patient morbidity and overall survival (OS) are associated with dexamethasone use. We studied dexamethasone-associated hyper-glycemia, leukocytosis, and accompanying complications in the peri-operative period. We also examined the effect of metformin treatment on GBM patient OS. We retrospectively studied 243 GBM patients admitted between 2014-2018. Patients with peri-operative glucose measurements and adequate follow-up to assess for complications were included. Metformin was used for treatment of diabetes or in the management of glucocorticoid-induced hyper-glycemia. Kaplan-Meier curves and log-rank p test were used for univariate analysis. Cox-proportional hazards model was used to generate adjusted hazard ratios for multivariate analysis. Dexamethasone dose was associated with hyper-glycemia and leukocytosis post-operatively. Poor glycemic control was associated with increased odds of 30-day any complication on univariate analysis and 30-day any complication and increased length of stay on multivariate analysis. We then demonstrated that metformin improved OS in methylated O6-methylguanine DNA methyltransferase gene (MGMT) promoter tumor patients (652 days, 95% CI 327 – 897, n = 25 vs 394 days, 95% CI 210 – 513, n = 63; P = .049). Non-diabetic MGMT-methylated tumor patients treated with metformin also had an improved median OS of 736 days, 95% CI 365 – 1036, n = 11 vs 395 days, 95% CI 210 – 513, n = 66; P = .01). Overall, peri-operative hyper-glycemia and higher average dexamethasone use are associated with poor glycemic control and leukocytosis. As a result, dexamethasone can increase the risk of peri-operative complications in GBM patients. Avoiding hyper-glycemia by limiting dexamethasone use or using Metformin may decrease the risk of complications and improve OS.