Correlation of Ki-67, p53 and bcl-2 Expression with Grade and Behavior of Ependymoma

Han, Jae Ho; Kim, Tai Seung

Abstract

Ependymomas constitute no more than 5 to 7% of all primary CNS neoplasm and their biologic behavior is difficult to predict by microscopic appearances. Recently, many studies have attempted to correlate biologic behavior with tumor proliferation index, tumor suppressor gene and oncogene using immunohistochemical stains. We evaluated 25 cases of surgically resected intracranial ependymomas for the proliferation activity using Ki-67, and expression of p53 and bcl-2 protein with regard to the prognosis. The cases were divided into 17 ependymomas (WHO Grade II), 3 papillary ependymomas (WHO Grade II), and 5 anaplastic ependymomas. Clinically, the patients were divided into two groups, recurrent (18 cases) or non-recurrent (7 cases). The Ki-67 proliferation index was significantly higher in the recurrent group (p<0.05) and in the younger ages (correlation index=0.534). Although Ki-67 proliferation index was higher in anaplastic ependymoma, it was not significant statistically (p>0.05). p53 protein expression tended to increase in the patients who had anaplastic ependymoma and in the recurrent group. bcl-2 expression was not correlated with histologic grade or recurrence of the tumor. We conclude that Ki-67 proliferation index and p53 expression are important markers for predicting biologic behavior of ependymoma.