Anaplastic oligodendroglial tumors: The Cleveland Clinic experience.

Abstract

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. Following surgery, 30% of patients were treated with chemotherapy (CT) alone, 14% were treated with radiotherapy (RT) and 47% received both CT and RT. Median progression free survival and median overall survival (OS) were 29.0 and 58.7 months respectively. On multivariate analysis, four factors were identified as independent predictors of OS: age at diagnosis (≥50 vs. <50, p=0.004), Hypothyroidism (p=0.009), multifocal disease (p=0.005) and 1p 19q co-deletion (p<0.001). Choice of initial therapy did not impact survival in this cohort of patients. Conclusions: Older age, hypothyroidism and multifocal disease were associated with higher mortality. 1p, 19q co-deletion was associated with lower mortality. [Table: see text]