Prognostic factors and survival in primary adult high grade brainstem astrocytoma: a population based study from 1973-2008.

Adult brainstem astrocytomas are a rare and heterogeneous group of malignancies. Most reports represent low-grade gliomas. This study used the Surveillance, Epidemiology and End Results (SEER) database to analyze the association between survival and demographic factors, tumor histology, and treatment characteristics among adult patients with high-grade brainstem astrocytoma (HGBSA). Adult patients with histologically confirmed diagnoses of primary HGBSA were studied. In univariate and multivariate analysis, we investigated the effect of demographics, tumor histology and treatment modality on survival. Overall median survival in the cohort of 240 adult patients was 7months, with 1, 2, 5 and 10year survival rates of 33.2%, 19.7%, 10.1%, and 8.3%, respectively. Age >50years (hazard ratio [HR] 1.98, 95% confidence interval [CI] 1.45-2.70, p<0.001) and grade IV versus grade III tumor (HR 1.61, 95% CI 1.15-2.26, p=0.006) were associated with statistically significant increased mortality in multivariate analyses. Surgical intervention trended toward association with lower mortality (HR 0.68, 95% CI 0.47-1.01, p=0.055). Our findings suggest that in patients with HGBSA, younger age and lower-grade histology are associated with better prognosis. Surgical intervention trended towards a significant association with better outcome, while radiation treatment was not associated with a statistically significant benefit in survival.