Analysis of the prognostic significance of selected morphological and immunohistochemical markers in ependymomas, with literature review.
The molecular genetic events involved in the development of ependymal neoplasms are not well understood. This study retrospectively examines 41 ependymomas; in all tumors the cyclin D1 labeling index (LI) (percent of positive immunostaining tumor cells) was correlated with MIB-1 LI and outcome. The study included 41 patients (25 males and 16 females) ranging in age from 1.5 to 70 years (mean, 30.7 years). Twenty-five patients underwent a subtotal resection or biopsy, and 16 underwent a gross total resection. Thirty-two patents had an ordinary or tanycytic ependymoma, and 9 had anaplastic/malignant tumors. The cyclin D1 LI ranged from 0 to 8.2 (mean, 0.7); 21 tumors had an LI of 0, and 8 had an LI of >1.0. The MIB-1 LI ranged from 0.1 to 34 (mean, 4.6); 16 tumors had an LI >2.0. All 8 patients with a cyclin D1 LI of >1.0 had an MIB-1 LI of >2.0. The tumors in the 6 of 8 patients with a cyclin D1 LI of >1.0 were classified as anaplastic/malignant tumors. The findings at the most recent follow-up were as follows: alive with no evidence of tumor (n = 11; mean, 64.1 months); died with evidence of tumor (n = 11; mean, 45.9 months); alive with tumor (n = 10; mean, 39.0 months). Two patients were alive with evidence of residual disease at follow-up intervals of 7 and 16 months but were lost to further follow-up. The remaining 6 patients either were lost to follow-up or else died in the immediate postoperative period. Cyclin D1 and MIB-1 LI did not reliably correlate with clinical outcome or recurrence. All tumors with an elevated cyclin D1 LI also had an elevated MIB-1 LI; however, the converse was not true. An elevated cyclin D1 LI (>1.0 in this study) appeared to be associated with anaplastic/malignant histology; however, cyclin D1 LI along with MIB-1 LI and histology did not always reliably correlate with clinical outcome.