title: The proliferative potential of the pilocytic astrocytoma: the relation between MIB-1 labeling and clinical and neuro-radiological follow-up.
abstract: The proliferative potential of 39 pilocytic and 5 low grade astrocytomas was studied in relation to the Ki-67 activity as measured by the MIB-1 Labelings Index. The results were correlated to the biological behaviour of the tumor as measured by clinical and neuro-radiological (CT- or MRI-scans) follow-up of the patient. This study was undertaken to answer the question whether MIB-1 expression reflects differences in biological behaviour of these tumors, such as rapid progression of residual tumor or stable remaining tumor. MIB-1 LI values ranged from 0 to 19% in the group of pilocytic astrocytomas (mean 4.2%) and from 0 to 15% in the 5 low grade astrocytomas (mean 4,2%). All patients were operated and 23 of them had incomplete tumor resection as proven on postoperative neuro-imaging studies. Those 23 patients could be subdivided into two groups; one without progression of residual tumor during follow-up (n=12) and the other with tumor progression (n=11). mean MIB-1 LI in the group with 'quiescent' tumor tended to be lower than in the group with progressive tumor: 3,3% vs. 6,6%. Residual tumors which were negative for MIB-1 staining showed fewer progressions of residual tumor compared to those being positive for MIB-1 staining, however this difference was not significant (p=0, 15, Fisher exact test). Tumor samples of a second operation of the same patient had lower MIB-1 LI values than those of the samples taken at first operation. The proliferating potential seemed to be decreased after part of the tumor was resected. Pilocytic astrocytomas with a negative MIB-1 LI are unlikely to show progression of residual tumor after partial resection. MIB-1 staining might be an additional tool in determining the frequency and duration of follow-up and in making decisions regarding further treatment of a patient operated for a pilocytic astrocytoma with residual tumor.
authors.affiliation: University Hospital, Vrije Universiteit, Department of Neurosurgery, Amsterdam, The Netherlands.
authors.forename: C M
authors.initials: CM
authors.lastname: Dirven
authors.forename: J
authors.initials: J
authors.lastname: Koudstaal
authors.forename: J J
authors.initials: JJ
authors.lastname: Mooij
authors.forename: W M
authors.initials: WM
authors.lastname: Molenaar
mesh_terms: D000293:Adolescent; D034961:Antigens, Nuclear; D001254:Astrocytoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D019394:Ki-67 Antigen; D008279:Magnetic Resonance Imaging; D008297:Male; D008940:Mitotic Index; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009687:Nuclear Proteins / Q000378:metabolism*; D011859:Radiography
chemical_list: D034961:Antigens, Nuclear; D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D009687:Nuclear Proteins