Nucleolin overexpression is associated with an unfavorable outcome for ependymoma: a multifactorial analysis of 176 patients

Ependymoma typically has a better overall survival rate than most gliomas. Only a few comprehensive clinical studies have been published, but these are mostly from Western countries and use small sample sizes. Histopathological classification is not sufficient to show variable outcomes, and fails to show prognostic markers of the diverse outcomes; hence, it is essential to understand biological mechanisms. In this study, 176 ependymoma samples ( World Health Organization grade II and III) were reviewed at Huashan Hospital. Both children and adults were included. We performed multifactorial analyses of clinical prognostic factors and the biomolecular marker expressions of nucleolin, epidermal growth factor receptor ( EGFR) and caveolae-associated protein caveolin-1 by immunohistochemistry. We identified the probabilities of progression-free survival and overall survival using univariate and multivariate statistical methods. The participants were diagnosed with ependymomas between 2002 and 2010, including distributions of tumor locations in intracranial and extracranial regions. Nucleolin was overexpressed in 67 % of our samples, demonstrating a subgroup with poor outcome; particularly infratentorial and anaplastic ependymomas. There was no significant correlation between the expression of EGFR and caveolin-1 and clinical outcomes. Clinically, inferior prognosis was observed with regard to age (<18 years), intracranial location, high grade ependymomas, and incomplete resection. We found that nucleolin was an unfavorable prognostic predictor for ependymomas. Moreover, our findings show a subset of aggravating outcomes in high-grade and posterior fossa tumors.