title: Practical value of MIB-1 index in predicting behavior of astrocytomas.
abstract: BACKGROUND
  The MIB-1 labeling index (LI) has proved to be useful in assigning grading and prognosis to astrocytomas. The purpose of our study was to analyze the utility of MIB-1 LI in differentiating astrocytomas of varying grades and the possible relationships of MIB-1 LI with clinical parameters like age and sex. We also wanted to study the prognostic role of MIB-1 index in predicting behavior of astrocytomas.
  
  
  METHODS
  Our study included 145 patients with astrocytic tumors of varying grades. Immunolabeling for all patients was done using MIB-1 antibody. Survival data could be obtained for 64 patients. A Mann-Whitney U test was used to test the difference in MIB-1 LI between different histological grades. The univariate analysis was done by the Kaplan-Meier method, and the multivariate analysis for survival was performed using the Cox proportional hazard model.
  
  
  RESULTS
  Significant differences were noted in mean MIB-1 LI of high-grade and low-grade diffuse astrocytomas. MIB-1 LI did not vary significantly with age and sex. Univariate analysis showed favorable prognostic factors for low histopathological grade, young patient age and low MIB-1 LI; however, multivariate analysis showed that only histopathological grade had independent prognostic significance.
  
  
  CONCLUSIONS
  Our study proves that MIB-1 LI is not dependent on factors like age and sex and is solely dependent on histological grade. Though the average level of MIB-1 LI varies considerably in the different grades of astrocytomas, considerable overlap can be observed between them. MIB-1 LI is a very useful adjunct to the histopathological diagnosis and can be of great help in situations where the clinical and radiological findings do not correlate with histological diagnosis.
authors.affiliation: Department of Histopathology, Apollo Specialty Hospital, Chennai, India. drmosesa@yahoo.com
authors.forename: M Moses
authors.initials: MM
authors.lastname: Ambroise
authors.forename: Charu
authors.initials: C
authors.lastname: Khosla
authors.forename: Mitra
authors.initials: M
authors.lastname: Ghosh
authors.forename: V S
authors.initials: VS
authors.lastname: Mallikarjuna
authors.forename: S
authors.initials: S
authors.lastname: Annapurneswari
mesh_terms: D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D011379:Prognosis; D012720:Severity of Illness Index; D016019:Survival Analysis; D044767:Ubiquitin-Protein Ligases / Q000032:analysis*
chemical_list: C513496:MIB1 ligase, human; D044767:Ubiquitin-Protein Ligases