Ag-NORs, nucleus-nucleolus-associated antigens (Ki67, PCNA, P-105 and p-120): prognostic markers of meningioma recurrence

The predictive significance of some nucleus-nucleolus associated markers, such as Ag-NOR, Ki67, PCNA, p-120, P-105, for the recurrency of meningiomas was investigated. A retrospective analysis was performed on a series of transitional meningiomas and of their recurrencies. Similar meningiomas but with no recidivism were used as controls. All cases were represented by women between the V and the VI decade of age. Besides, having all tumors presented with a cranial convexity localization total removal had been achieved. Recurrencies had taken place after 4.5 and 7.5 years in ten and two women, respectively. In all cases considered, the tumoral histotype did never present with structural elements in general suggestive of recurrence, such as high degree of cellularity, atypia, nuclear polymorphism, necrosis, appreciable mitotic index. On histological seriated 3 microns thick sections the silver staining technique of nucleolar organizer region-associated proteins (NORs) and the Ki67, PCNA, p-120, P-105 immunostaining ABC technique were applied. For each case 1000 tumoral cells were counted, with evaluation of the number of Ag-NOR dots and the percentage of Ki67, PCNA, p-120, P-105 positive cells. From the analysis, a mean value of Ag-NOR dots resulted of 6.44 +/- 0.65 in primitive meningiomas and of 6.53 +/- 0.88 in their respective recurrencies. In the control tumors the mean value of Ag-NOR dots resulted to be 3.53 +/- 0.55. Such difference between tumors that had repeated and controls that had not, was statistically significant (p < 0.001). For what concerns the expression of immunocytochemical relevant markers the percentage of positive cells, in primitive tumors (P), in recurrencies (R) and in the controls (C) was, namely, as follows: Ki67 (P: 14%, R: 12%, C: 6%); PCNA (P: 38%, R: 37%, C: 8%); and p-120 (P: 57%, R: 62%, C: 12%). The expression of P-105 was but occasional and without significance. From the data described, one can conclude that the evaluation of the whole of the markers considered in transitional meningiomas does predict recidivism.