Clinical Study Prognostic factors and survival in primary adult high grade brainstem astrocytoma: A population based study from 1973–2008 Mahua Dey a , Yimo Lin b , Stephanie Melkonian c , Sandi Lam b,⇑ a University of Chicago, Section of Neurosurgery, Chicago, IL, USA b Baylor College of Medicine, Texas Children’s Hospital, Department of Neurosurgery, 6701 Fannin Street, CCC Suite 1230-01, Houston, TX 77030, USA c MD Anderson Cancer Center, Department of Cancer Epidemiology, Houston, TX, USA article info Article history: Received 16 December 2013 Accepted 24 December 2013 Available online xxxx Keywords: Brainstem astrocytoma Brainstem glioma Brainstem tumor Malignant glioma SEER abstract 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 ana- lyze the association between survival and demographic factors, tumor histology, and treatment character- istics 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 7 months, with 1, 2, 5 and 10 year survival rates of 33.2%, 19.7%, 10.1%, and 8.3%, respectively. Age >50 years (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 inter- vention trended toward association with lower mortality (HR 0.68, 95% CI 0.47–1.01, p = 0.055). Our find- ings 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. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Brainstem astrocytomas (BSA), the most common neoplasm involving the brainstem (midbrain, pons, or medulla oblongata), comprise 1% of all adult brain tumors and 10% of all pediatric brain tumors [1]. The incidence of BSA has a bimodal distribution, with the first peak in the age group 4–13 years and a second peak in the fourth decade [2]. Unlike other primary brain tumors, where children tend to have better prognoses than adults [3–5], pediatric patients are shown to have worse prognoses than adults in the case of BSA [6]. Adult BSA are a poorly understood, heterogeneous group of malignancies with varying radiological patterns and variable prognoses [4,7]. Published median survival times for adults with BSA range from 64 to 85 months, which is significantly better than published median survival times for pediatric patients, which is 12 months [3–5]. Similar to primary gliomas, BSA can be classified into four histological grades (I to IV), where grade I and II represent low-grade gliomas and grade III anaplastic astrocytoma (AA) and grade IV glioblastoma multiforme (GBM) represent high-grade gliomas. Pathological studies have shown a trend towards low- grade histology (grade II glioma) in up to 80% of patients with adult BSA, whereas in children, grade IV glioma is the most frequently reported histology type (50–60% of patients) [8]. Thus the reported median survival of adults with BSA is likely skewed towards low- grade gliomas. Tumor grade is reported to be a significant factor in predicting survival in adults [6]. Guillamo et al. classified all adult BSA into three different subgroups: (1) focal tectal brainstem glioma, (2) diffuse intrinsic brainstem glioma and (3) malignant brainstem glioma. They showed survival varied substantially among the three groups, with 100% survival at 5 years, and a median survival of 7.3 years and 11.2 months respectively [4]. Studying this heterogeneous entity as a group leaves a major gap in our understanding of the epidemiology, diagnosis and optimal treatment strategy for this sub-group of high-grade malignancy. Although a few small studies have shown that adults with high- grade brainstem astrocytoma (HGBSA) have a worse prognosis than adults with low-grade brainstem glioma [4], there is a paucity of published studies analyzing an adequate number of patients to draw sound conclusions and guide treatment strategy. In this study of adult HGBSA, we aimed to determine which fac- tors, including demographics, tumor histology and treatment http://dx.doi.org/10.1016/j.jocn.2013.12.011 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +1 832 822 3950; fax: +1 832 825 9333. E-mail address: sklam@texaschildrens.org (S. Lam). Journal of Clinical Neuroscience xxx (2014) xxx–xxx Contents lists available at ScienceDirect Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn Please cite this article in press as: Dey M et al. Prognostic factors and survival in primary adult high grade brainstem astrocytoma: A population based study from 1973–2008. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2013.12.011