Pleomorphic xanthoastrocytomas: institutional experience of 18 patients

Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade glioma (World Health Organization Grade II) that most often presents in the first two decades of life. We summarize and present our institutional experience in the management of these tumors. All patients managed for PXA at the University of California San Francisco were retrospectively identified through chart review. Patient demographics, tumor characteristics, management, and follow-up were extracted using medical records. Primary endpoints were overall (OS) and progression-free survival (PFS). In total, nineteen patients were treated for PXA from 1993-2011. Clinical data were available for analysis in 18 patients. Median OS was 209.0 months after date of surgery, with both 5 year and 10 year survival rates of 94%. In this patient cohort, tumor grade (p=0.07), age (p=0.32), and extent of resection (p=0.58) did not predict OS. The majority of tumors (78%) recurred. Median PFS was 21.7 months, with 5 year and 10 year recurrence-free rates of 28% and 22%. On univariate analysis, tumor grade (p=0.01), but not age (p=0.51), size (p=0.30), or extent of resection (p=0.21), was the only covariate predictive of PFS. In patients presenting with higher tumor grade, however, earlier recurrence was demonstrated. Furthermore, the majority of recurrences (36%) occurred within the first 6 months post-operatively, which indicates the need to closely follow patients for that time.