Abstract:
O6-methylguanine-DNA methyltransferase ( MGMT ) is a key marker correlated with the tolerance of malignant glioma to alkylating agents, such as temozolomide ( TMZ ). The objective of the present study was to evaluate the efficacy of salvage chemotherapy based on the MGMT protein expression in recurrent malignant gliomas. Methods: Thirty patients with pathologically confirmed malignant gliomas were enrolled. The focus of infection was appraisable in all patients. MGMT protein expression was determined by immunohistochemistry. The patients were classified into positive ( PosG ) and negative ( NegG ) groups. A 5-day chemotherapy with non-TMZ conventional regimen or non-alkylating agents was administered to the PosG patients, whereas no restrictive chemotherapeutic regimen was administered to the NegG patients. Results: Based on all patients, the objective response rate ( ORR ) was 20.0%, the median progression-free survival time ( MPFST ) was 8 months ( 95% CI: 4.3-11.7 ), and the median overall survival time ( MOST ) was 16 months ( 95% CI: 7.4-24.6 ). Of the 30 tumor cases, 16 were MGMT-positive, whereas 14 were MGMT-negative. The ORRs of the PosG and NegG patients were 18.8% and 21.4% ( P > 0.05 ), respectively. MPFST values were 7 ( 95% CI: 3.1-10.9 ) and 8 months (95 % CI: 3.9-12.1), respectively, whereas MOST values were 16 ( 95% CI: 5.4-26.6 ) and 16 months ( 95% CI: 7.3-24.7 ), respectively. No statistically significant differences ( P > 0.05 ) were obtained. Conclusion: Salvage chemotherapy is of clinical benefit for patients with recurrent malignant gliomas. Individualized chemotherapy based on the MGMT protein expression, especially for patients with MGMT positive tumor