Abstract
1) Results of chemotherapy for malignant gliomas. The randomized clinical trial BTSG 75-01 and recent meta-analysis of chemotherapy for malignant gliomas from 12 randomized trials showed that radiotherapy and chemotherapy with nitrosoureas offered a significant prolongation of survival over radiotherapy alone. Interferon α and β do not appear to prolong the progression-free period and overall survival of patients with malignant gliomas. 2) Drug resistance to nitrosoureas and methods for overcoming this resistance. It was shown that the MGMT level in tumor cells correlates with the survival of patients with malignant gliomas who were treated with nitrosoureas. Depletion of MGMT before administering nitrosoureas is the method for overcoming nitrosoureas resistance. 3) Prediction of drug sensitivity. The MGMT level in tumor cells seems to be a predictive factor for patients with malignant gliomas who are treated with nitrosoureas and temozolomide. 4) New drug. Temozolomide is the most promising new drug and a phase III study of concomitant radiotherapy plus temozolomide for newly diagnosed glioblastoma showed a survival benefit over radiotherapy alone. Mechanisms of resistance to temozolomide are the MGMT level in the tumor cells, deficiency of the mismatch repair system and base excision repair, and DNA base excision repair seems to be a useful therapeutic target in mismatch repair system-deficient cells. 5) Molecular targeting therapy. A correlation between EGFR and survival of patients with glioblastoma was shown and EGFR is a reasonable molecular therapeutic target.
