Anaplastic oligodendroglial tumors: The Cleveland Clinic experience.

2100 Background: Anaplastic oligodendroglial tumors include both anaplastic oligodendroglioma (AO), and anaplastic oligoastrocytoma (AOA), histological categories of WHO grade 3 gliomas. There is limited data on specific prognostic factors for patients with these tumors. Methods: After obtaining IRB approval, the Cleveland Clinic Brain Tumor and Neuro-Oncology Center’s database was used to identify patients with histologically confirmed AO and AOA at the time of diagnosis. Multivariable analysis was conducted with use of a Cox proportional hazards model and a stepwise selection algorithm that used p<0.05 both as the criteria for entry and retention in the model to identify independent predictors of survival. Results: Chart records of 139 patients, 52% of whom were male, diagnosed between 1992 and 2009 were included for analysis. Median age at presentation was 47 years (range, 18-83 years). 22% of patients had biopsy only, 35% had gross total resection, 43% had near total resection or subtotal resection. F...