Rationale:

Standard therapy for anaplastic oligodendrogliomas and mixed oligoastrocytomas includes radiation and chemotherapy. However, due to the potential long-term central nervous system toxicity from radiation, researchers speculate that it may be better to reserve radiation therapy for progressive disease. In addition, some patients with anaplastic oligodendroglioma and mixed oligoastrocytoma have unusually chemosensitive tumors. Previous research indicates that brain tumor patients with a deletion of the 1p chromosome have a higher response to the chemotherapy drug temozolomide.

Temozolomide has demonstrated clinical antitumor efficacy against malignant gliomas at both relapse and initial diagnosis. This drug appears to have less adverse effects compared to other drugs used against brain tumors. Therefore, temozolomide is often better tolerated in brain tumor patients compared to other brain tumor drugs. The current study builds on previous research to test the efficacy of chemotherapy alone in patients with anaplastic oligodendroglioma and mixed oligoastrocytoma.

Purpose:

This study will evaluate response rate, or how the disease size changes in patients, and survival without disease growth, in patients with anaplastic oligodendroglioma and mixed oligoastrocytoma treated with temozolomide. Quality of life will also be assessed in this patient population treated with the study regimen.

Treatment:

Study participants will be treated with the drug temozolomide. This drug will be administered in oral pills. Temozolomide will be taken for seven consecutive days followed by seven days without the drug. This treatment schedule of seven days on temozolomide followed by seven days off will continue throughout the study. Several tests and exams will be given to closely monitor patients. MRI scans will be performed every 8 weeks to measure disease response. Temozolomide as a study drug will be given to study participants for a total of 8 week four cycles. However, treatments will be discontinued due to disease growth or unacceptable adverse events.

Inclusion Criteria:

• anaplastic oligodendroglioma or mixed oligoastrocytoma
• age > 18
• Karnofsky status > 70%
• adequate bone marrow, liver and renal function

Exclusion Criteria:

• prior chemotherapy or cranial irradiation