The relative value of postoperative versus preoperative Karnofsky Performance Scale scores as a predictor of survival after surgical resection of glioblastoma multiforme.

The Karnofsky Performance Scale (KPS) score is a widespread metric to stratify patient prognosis and determine appropriate management in glioblastoma multiforme(GBM). Low preoperative KPS values have been associated with shorter overall survival (OS). However, surgical resection can have a dramatic effect on a patient's functional status which subsequently alters their KPS score. To determine the predictive value of preoperative verses postoperative KPS scores in terms of OS in patients with GBM. We conducted a retrospective review of 163 patients who underwent initial surgical intervention for pathologically proven GBM at our institution between 2003 and 2013. Pre and postoperative performance status, demographic, operative, and treatment variables were recorded for each patient. Multivariate regression analysis identified predictors of prolonged OS. The adequacy index was calculated to compare the predictive value of preoperative and postoperative KPS score. Median preoperative and postoperative KPS scores were 70 and 80, respectively. Overall, 92 (57 %) patients experienced an improvement in their KPS score, 40 (25 %) remained stable, and 29 (18 %) declined. Higher postoperative KPS (P = 0.0001), radiation therapy (P < 0.0001), younger age (P = 0.0443) and the absence of diabetes (P = 0.0006) were each independently associated with increased OS in a multivariate regression model. Postoperative KPS score has superior predictive value compared to pre-operative KPS score (A = 0.758 vs. 1.002). Postoperative KPS scores have superior predictive capabilities in terms of OS in GBM and should replace preoperative KPS scores when estimating prognosis in this population.

Multi-institutional validation of a preoperative scoring system which predicts survival for patients with glioblastoma.

Glioblastoma is the most common and aggressive type of primary brain tumor in adults. Average survival is approximately 1 year, but individual survival is heterogeneous. Using a single institutional experience, we have previously identified preoperative factors associated with survival and devised a prognostic scoring system based on these factors. The aims of the present study are to validate these preoperative factors and verify the efficacy of this scoring system using a multi-institutional cohort. Of the 334 patients in this study from three different institutions, the preoperative factors found to be negatively associated with survival in a Cox analysis were age >60 years (p<0.0001), Karnofsky Performance Scale score ≤80 (p=0.03), motor deficit (p=0.02), language deficit (p=0.04), and periventricular tumor location (p=0.04). Patients possessing 0-1, 2, 3, and 4-5 of these variables were assigned a preoperative grade of 1, 2, 3, and 4, respectively. Patients with a preoperative grade of 1, 2, 3, and 4 had a median survival of 17.9, 12.3, 10, and 7.5 months, respectively. Survival of each of these grades was statistically significant (p<0.05) in log-rank analysis. This grading system, based only on preoperative variables, may provide patients and physicians with prognostic information that may guide medical and surgical therapy before any intervention is pursued.

Type 2 diabetes mellitus and obesity are independent risk factors for poor outcome in patients with high-grade glioma.

Type 2 diabetes mellitus (DM) and obesity are known risk factors for poor outcomes in patients with systemic malignancies but are not well-studied in the brain tumor population. In this study we asked if type 2 DM and elevated body mass index (BMI) are independent risk factors for poor prognosis in patients with high-grade glioma (HGG.). We conducted a retrospective cohort study of 171 patients surgically treated for HGG at a single institution. BMI and records of pre-existing type 2 DM were obtained from medical histories. Variables associated with survival in a univariate analysis were included in the multivariate Cox model if P < 0.10. Variables with probability values >0.05 were then removed from the multivariate model in a step-wise fashion. Mean age at diagnosis was 55.0 ± 17.3 years. Fifteen (8.8%) patients had a history of type 2 DM. Fifty-eight (35.8%) patients had a BMI < 25, 55 (34.0%) BMI 25-30, and 49(30.2%) BMI > 30. Radiation therapy, temozolomide, and higher KPS score were independently associated with prolonged survival while increasing age was associated with decreased survival. DM (P = 0.001) and increasing BMI (P = 0.003) were found to be independently associated with decreased survival. Diabetics had a decreased median overall survival (312 vs. 470 days, P = 0.003) and PFS (106 vs. 166 days, P = 0.04) compared to non-diabetics. Increasing BMI (<25, 25-30, and >30) was also associated with decreased median PFS: 195 vs. 165 vs. 143 days, respectively. Pre-existing DM and elevated BMI are independent risk factors for poor outcome in patients with HGG.