Prognostic nomogram in elderly patients with glioblastoma.

2096 Background: Glioblastoma (GBM) is the most common malignant primary brain tumor. More than half the cases occur in patients aged ≥65 years; however, there is limited data on specific prognostic factors in these patients and there is a lack of easy to use nomograms in elderly GBM patients to provide them prognostic information. Methods: The Cleveland Clinic Brain Tumor and Neuro-Oncology Center’s database was used to identify elderly patients with GBM ( ≥65 years at the time of diagnosis). Multivariable analysis was conducted to identify independent predictors of survival using a Cox proportional hazards model and a stepwise selection algorithm with p=.10 as criteria for entry and retention. "Points" were assigned to each of these poor prognostic features and prognostic groups were formed based on the total number of calculated points. Results: 512 GBM patients with a median age of 73 years (range 65-96, 54% male) were included in the final analysis. On multivariable analysis six factors were identifi...