The hTERT‐protein and Ki‐67 labelling index in recurrent and non‐recurrent meningiomas

Abstract

Meningiomas are considered as benign neoplasms affecting the coverings of the central nervous system and compromise approximately 20% of all intracranial tumours. However, a number of these tumours recur even after total resection. The aim of this study is to evaluate the prognostic significance for recurrence of the human telomerase catalytic subunit (hTERT) in the cells of meningiomas. The expression of hTERT-protein can be evaluated by immunohistochemical staining using a monoclonal antibody against hTERT (clone 44F42, NCL-L-hTERT). The interdependence between tumour recurrence and cell proliferation in this study is analysed by Ki-67 immunoreactivity (clone MIB-1). Archival material from 29 non-recurrent and 32 recurrent tumours has been evaluated, including specimens from World Health Organization (WHO) stages I (n = 73), II (n = 2) and III (n = 12). Although the tumours were categorized as benign meningiomas following the WHO classification, recurrence in 22 of 50 cases did not correlate with the tumour stage. For hTERT staining, the following results were found for nucleolar and total nuclear staining, respectively: non-recurrent meningiomas, 2.9% (+/- 7.7) and 3.0% (+/- 8.0); recurrent meningiomas at first resection, 16.8% (+/- 19.7) and 31.6% (+/- 30.2). Concerning the Ki-67 labelling index (LI): for the group of non-recurrent meningiomas, results were 2.1% (+/- 1.7) and for the recurrent group at first resection, 1.7% (+/- 2.0). A significant difference was seen for the hTERT staining (P < 0.001) between the non-recurrent and recurrent meningiomas, whereas no statistical significance was found for Ki-67. In conclusion hTERT-positive meningiomas had a high incidence for recurrence. Ki-67 was a good marker of cell proliferation status of the tumours, but did not correlate with recurrence; thus, hTERT alone seemed to be a potential predictor for recurrence.

Relation between telomerase activity, hTERT and telomere length for intracranial tumours

“…Telomere length is maintained by telomerase activity and can be influenced in different ways and by various factors (26). From literature it is clear that telomerase activity can be regarded as a prognostic marker for malignancy (12,13,16). In contrast to malignant intracranial tumours, benign meningiomas seldom express telomerase activity.…”

“…Some results have already been published on telomerase and telomeres in intracranial tumours (12)(13)(14), showing a correlation between telomerase activity and histopathological grading. It has been reported that hTERT rather than telomerase activity could be used as a prognostic marker for progression and potential recurrence (15)(16)(17). Moreover, hTERT could be considered as an early signal towards indefinite life span (18).…”

Presence of matrix metalloproteinase–2 and tissue inhibitor matrix metalloproteinase–2 gene polymorphisms and immunohistochemical expressions in intracranial meningiomas

“…25 In contrast to this finding, Maes et al found Ki-67 to be a good marker of the cell proliferation status of the tumors but found no correlation with recurrence. 9 They observed that human telomerase catalytic subunit (hTERT) alone seemed to be a potential predictor of recurrence. In our study, the statistical results showed that the Ki-67 labeling index was highly correlated with meningioma grading but not with brain invasion.…”

Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Expression in Canine and Feline Meningioma

“…The fact that Ki67 expression corresponds to WHO classification and tends to be correlated with the biologic behavior of these different groups (i.e., benign, atypical, and malignant) does not indicate whether the tumor has a tendency to recur. 24 In canine and feline meningioma, the finding of MMP expression calls for further investigations into the role played by MMPs, perhaps in relation to a revised morphologic malignancy grading and to the recurrence of intracranial or spinal meningioma, whether benign or malignant, along with other factors influencing tumor invasion into the brain or spinal cord and its recurrence, such as location, extent of surgery, intraoperative findings, radiographic aspects, age of the patient, edema, cytokine production, and possibly the chromosomal alteration.…”