title: Evaluation of O6-methylguanine-DNA methyltransferase enzyme expression effect on survival of patients with Grade 4 brain astrocytoma.
abstract: BACKGROUND
  High-grade astrocytoma (Grade 4) or glioblastoma multiforme (GBM) are deadly brain tumors. New therapies attempt to increase lifetime and quality of life in patients with malignant astrocytoma. O6-methylguanine-DNA methyltransferase (MGMT) enzyme expression may be effective in prognosis and response to treatment of these patients. The aim of this study was assessment of MGMT enzyme expression in patients with astrocytoma Grade 4.
  
  
  METHODS
  In this study, 48 patients with GBM that were treated with surgery, chemotherapy and radiotherapy were investigated and followed-up for 47 months for the survival rate. Pathology blocks of patients were examined for MGMT enzyme expression using immunohistochemistry method.
  
  
  RESULTS
  The patients were 34 males and 14 females. The ages ranged from 24 to 77 years, with a mean age of 53.52 ± 13.39 years. There was no significant difference between two groups (positive and negative MGMT enzyme expression) in overall survival (median [range] 11.5 [4-30] vs. 13 [5-22], P = 0.9). The results of our study showed that patients although who were undergone near total surgery had higher overall survival than the group of patients who had biopsy only however, it was not significant. Patients who were treated with temozolomide (TMZ) (Temodal, Merck Canada) had significant overall median survival (14.5) more than the patients who were treated with Procarbazine (Roche, Swiss)-Lomustine (Lilly, USA)-Vincristine (Lilly, USA) regimen (8.75) (P < 0.05).
  
  
  CONCLUSIONS
  O6-methylguanine-DNA methyltransferase enzyme expression had no effect on survival of patients with Grade 4 brain astrocytoma TMZ may increase survival rate.
authors.affiliation: Department of Radiotherapy and Oncology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Hemati
authors.affiliation: Department of Radiotherapy and Oncology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Sayadi
authors.affiliation: Department of Pathology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Parvin
authors.initials: P
authors.lastname: Mahzooni
authors.affiliation: Department of Radiology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mehry
authors.initials: M
authors.lastname: Sirous
keywords: Astrocytoma; O6-methylguanine-DNA methyltransferase; chemoradiation; glioblastoma multiforme; temozolomide
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