Comparison of chemotherapy regimens for malignant gliomas with positive MGMT protein expression: Experience of 51 cases
12522 Background: To compare the efficacy and toxicity of three chemotherapy regimens for MGMT positive gliomas. Methods: Fifty-one patients with histologically confirmed malignant gliomas and MGMT positive expression were enrolled in this study. The glioma tissues were examined for MGMT protein expression by immunohistochemistry. The patients were treated with: 1, regimen contained of nitrosourea (nitrosourea group) 11 cases; 2, regimen contained of temozolomide (temozolomide group) 18 cases; regimen contained of neither nitrosourea nor temozolomide(no alkylating agent group) 22 cases. Response to chemotherapy was evaluated according WHO criteria, and toxicity was evaluated according National Cancer Institute (NCI) criteria. Results: The overall objective response rate (CR + PR) for 51 cases with MGMT position gliomas was 20%, and disease control rate (CR+PR+SD) was 59%. The objective response rate and disease control rate in nitrosourea group, temozolomide group, and no alkylating agent group were 0%,18.2%,16.7% and 61.1%,31.8%,77.3%, respectively. There was significant difference between no alkylating agent group and nitrosourea group (P<0.05). Hematological toxicity and nausea/vomiting were main side-effect observed in nitrosourea group. While there was comparative lower incidence of side-effect in temozolomide group. Hematological toxicity, nausea/vomiting, and alopecia were main side-effect observed in no alkylating agent group. Though there was higher incidence of 3–4 grade hematological toxicity in this group, but it could recovered by oneself in one week or through treatment with G-CSF for 3–5 days. Conclusions: Regimen contained no alkylating agent group can obtain higher response rate and thus is worth of recommending to patients with MGMT positive gliomas. However, since modest response rate and good toleration, regimen with temozolomide shouldn’t be given up in MGMT position gliomas. Nevertheless, It is necessary to discover more efficiency way of using temozolomide. Nitrosourea should not be recommended to MGMT position glioma patients. No significant financial relationships to disclose.