Immunohistochemical markers for intracranial ependymoma recurrence - An analysis of 88 cases

Intracranial ependymomas are the third most common primary brain tumor in c hildren. Although clinical and histological criteria for ependymoma prognos is are recognized, studies have reported contradictory results. Prognostic significance based on immunohistochemistry of ependymomas has been reported in a few studies. Eighty-eight patients with intracranial ependymomas were examined retrospectively for immunoexpression of various tumor-associated antigens and apoptosis. The results demonstrated significant preponderance of expression of the tenascin, vascular endothelial growth factor protein ( VEGF), epidermal growth factor (EGFR), and p53 protein in high-grade tumors . Also high-grade ependymomas revealed more prominent labeling indices (LI) for proliferative marker Ki-S1 and lower LI for cyclin-dependent kinase in hibitor p27/Kip1. For low-grade ependymomas the progression free survival t ime (PFS) was found to be significantly shorter for Ki-S1 LI greater than o r equal to 5%, and for tenascin, VEGF, and EGFR positivity. For high-grade ependymomas PFS was found to be significantly reduced for age < 16 years, s ubtotal tumor removal, p27 LI < 20%, p53 positivity, and for apoptotic inde x (AI) < 1%. The classification regression tree analysis exhibited four gro ups of ependymomas; (1) low-grade tenascin negative (32 cases, recurrence r ate = 0), (2) high-grade with AI greater than or equal to 1% (21 cases, rec urrence rate = 57%), (3) low-grade tenascin-positive (10 cases, recurrence rate = 89%), and (4) high-grade with AI < 1% (25 cases, recurrence rate = 1 00%). So, the immunohistochemical variables were found to be strongest pred ictors of ependymoma recurrence and they seem to be useful for assessing in dividual tumor prognosis in routinely processed biopsy specimen. (C) 2000 E lsevier Science B.V. All rights reserved.