[Relationship between the expression of O6-methylguanine-DNA methyltransferase in glioma and the survival time of patients].

BACKGROUND & OBJECTIVE: Previous studies showed that the DNA-repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) is one of drug resistant factors that affect chemosensibility of glioma. This study was to analyze the relationship between the expression of MGMT in glioma and the survival time of patients,and supply references to make molecular classification for glioma based on drug resistant mechanism. METHODS: MGMT expression in 311 glioma specimens was examined by tissue array technology and immunohistochemistry method, all patients had been followed up for 5 years, and the materials were analyzed statistically. RESULTS: The positive expression of MGMT was 126 in 311 gliomas (40.51%), among them, 61 in 121 astrocytomas (50.41%), 18 in 70 oligodendrogliomas (25.71%), 18 in 64 oligoastrocytomas (28.13%), 29 in 56 glioblastomas (51.79%); 68 in 186 grade I-II gliomas (36.56%), and 58 in 125 grade III-IV gliomas (46.40%). The difference of MGMT expression between grade I-II and grade III-IV gliomas was significant (P< 0.001). According to Kaplan-Meier's survival curves and log-rank test, patients with MGMT expression showed a shorter survival time than those with no MGMT expression (P< 0.05). CONCLUSION: MGMT expression in glioma correlates with histopathological type and tumor grade. Patients with MGMT expression show a shorter survival time than those with no MGMT expression.