Central nervous system tumors

Introduction

Chemotherapy, immunotherapy, and biological response modifiers were tested in clinical trials for brain tumors. Results of these studies published in 2003 and 2004 are reviewed.

Materials and methods

Major peer-reviewed journals in the disciplines of neurosurgery, neurology, medical oncology, and radiation oncology were surveyed. Results of phase II and phase III clinical trials testing chemotherapy, gene therapy, immunotherapy, and radiosensitizers for adults and children with malignant and low-grade glioma, primary central nervous system lymphoma (PCNSL), brain metastasis, medulloblastoma/primitive neuroectodermal tumor (PNET), and germ cell tumors were reviewed.

Results

Nitrosourea and temozolomide were tested as monotherapy or in combination with other agents as neoadjuvant, concurrent, and adjuvant treatment with radiotherapy for newly diagnosed malignant glioma in adults, including high-risk treatment groups, such as the elderly. Trials for recurrent malignant glioma included novel therapies, dendritic vaccine therapy, gene therapy and immunotherapy. High-dose chemotherapy with bone marrow rescue was tested in anaplastic oligodendroglioma (AO). Seven additional studies were performed to treat recurrent oligodendroglioma (O). Nine clinical trials for PCNSL emphasized the use of high-dose systemic methotrexate, temozolomide, and rituxin. Chemotherapy and immunotherapy were used to treat low-grade glioma in 7 studies. Intra-arterial and (IT) chemotherapy were used for metastatic disease. Treatment protocols for children were compared using multi-agent chemotherapy for malignant glioma, brainstem glioma, medulloblastoma, and germ cell tumors.

Conclusion

Multi-agent chemotherapy is successful for some pediatric brain tumors and PCNSL in adults. Vaccine, immunotherapy, and other gene therapies are still under investigation. Temozolomide and nitrosourea, specifically degradable polymer wafers, had the best results for malignant gliomas in adults. Treatment standards have been established for medulloblastoma/PNET. Treating malignant glioma in children remains problematic.