Abstract: Objective To study the expressions of O6-methylguanine-DNA methyltransferase(MGMT) and Ki-67 in glioma tissues and to evaluate the relationship between the expression of MGMT, Ki-67 and prognosis. Methods The gender, age, pre-operation Karnofsky performance status and progression-free survival time and overall survival time of 79 patients with gliomas were recorded, and then the expressions of Ki-67 and MGMT were tested by immunohistochemical technique for paraffin sections. Correlation of Ki-67 and MGMT with progression-free survival time and overall survival time was analyzed by multiple stepwise regression procedure. The comparision of Kaplan-meier survival curves of progression-free survival time and overall survival time according to MGMT expression was analyzed by log-rank method. Results No correlations were found among gender, age, pre-operation Karnofsky performance status and Ki-67 labeling index with progression-free survival time and overall survival time in the patients gliomas(P＞0.05). Negative correlation was confirmed between MGMT labeling index and progression-free survival time(r=0.074, P＜0.05), statistically significant correlation was also demonstrated between MGMT labeling index and overall survival time(r=-0.127, P＜0.001). According to MGMT labeling index, all patients were divided into two groups, MGMT labeling index ≤15% and MGMT labeling index ＞15%. Both progression-free survival time and overall survival time were significantly different between the two groups(P＜0.05 and P=0.001, respectively). Conclusion There was no correlation between Ki-67 antigen expression in glioma tissues and patient prognosis. MGMT expression in gliomas is correlated with patient progression-free survival time and overall survival time, so immunohistochemical assessment of MGMT may help predict patients' prognosis in clinical practice.

Key words: glioma, O6-methylguanine-DNA methyltransferase, Ki-67, immunohistochemistry