Impact of glycaemia on survival in glioblastoma patients

Background: Hyperglycemia has been associated with worse survival in glioblastoma (GBM) patients. This study aims to assess whether there is an independent association between glycemia and survival in GBM patients treated with radiotherapy (RT) and temozolomide (TMZ). Materials and Methods: This was a retrospective chart review of GBM patients treated radically with RT and TMZ chemotherapy between 2004 and 2010. We calculated a time-weighted mean (TWM) glucose based on glucose values from diagnosis to 4 weeks after completion of RT and investigated the association of these values with survival, accounting for confounding factors including time weighted mean dexamethasone dose, age, body mass index (BMI), pre-existing diabetes and performance status. Results: In total, 277 patients with a mean age of 55 years (18–77 years) with a mean body mass index of 26.7±4.9kg/m2 were evaluated. Patient performance status was ECOG 0–1 in 89%. Time-weighted mean daily dexamethasone dose was 6.7mg (0–32.9mg). After a median follow up of 15 months (1–104 months), the median survival was 15 months. The median TWM glucose from diagnosis to 4 weeks after completing RT was 6.5mmol/L. For patients with a mean glucose ≤6.5mmol/L and >6.5mmol/L, the median survival was 20 months and 14 months, respectively. On univariable analysis, the following variables were associated with survival: TWM glucose, TWM dexamethasone dose, age, BMI and ECOG performance status. On multivariable analysis, TWM glucose remained an independent predictor of survival such that patients with mean glucose >6.5mmol/L had an adjusted hazard ratio of 1.7 (p