KI-67 ANTIGEN EXPRESSION AS A PROGNOSTIC FACTOR IN PRIMARY AND RECURRENT ASTROCYTOMAS

Background and purpose. - Histological grading is widely used to evalu ate the prognosis for patients with astrocytic tumors. Many compliment ary methods have been introduced, such as proliferation markers in ord er to better assess the proliferative potential of these gliomas. Meth ods. - Archival, paraffin embedded specimens of recurrent astrocytic t umors of varying grades from 22 patients were examined using antibodie s against Ki-67 (MIB-1). Labeling indices (LI) were analyzed at the fi rst and second operations and compared with tumor grades, age of the p atients and the time between the operations as well as the survival ti me. Results. - There was a progression of malignancy between the opera tions. Dividing Ki-67 labeling indices in less than or equal to 10 % v s. > 10 % significantly separated parameters such as the time between the first operation and relapse as well as the cumulative proportion o f survival. The proliferation fraction was an independent prognostic f actor. Conclusion. - Assessment of Ki-67 LI is highly recommended in a ddition to histology in evaluation of the malignancy potential of astr ocytic tumors.