MIB1 staining index and scoring of histologic features in meningioma. Indicators for the prediction of biologic potential and postoperative management

Background. The biology of brain tumors, including cell kinetics, has been studied. Recently, monoclonal antibody to Ki67 (MIB1), a nuclear protein related to cell proliferation, has been analyzed immunohistochemically using tissue prepared from paraffin embedded sections. Methods. The authors assessed the prognostic usefulness of various histologic indicators of the biologic potential of meningiomas in patients who underwent total resection (Simpson's Grade I and II) by evaluating the time to recurrence as an end point. Forty‐three patients with a total of 36 meningiomas and 7 hemangiopericytomas were investigated by immunohistochemical analysis using MIB1. Results. MIB1 staining index (SI) and histologic score were well correlated with the recurrence‐free interval (r = −0.6749, P = 0.002 and r = −0.4939, P = 0.027, respectively) and with each other (r = 0.7909, P < 0.001). The MIB1 SI and histologic score in the nonrecurrence group were significantly lower than those in the recurrence/metastasis group (P < 0.001 and P = 0.001, respectively). The values of these indicators showed that as the value increased, so did the recurrence rate. Conclusions. Evaluation using the MIB1 SI and total histologic score of meningioma is useful in assessing the prognosis as well as postoperative management of these patients.