• To determine the effects temozolomide has on low-grade gliomas [ Time Frame: 3 years ] [ Designated as safety issue: No ]
  

• To determine whether temozolomide is effective in preventing or delaying future tumor growth [ Time Frame: 3 years ] [ Designated as safety issue: No ]
  
• to determine the safety of temozolomide [ Time Frame: 3 years ] [ Designated as safety issue: Yes ]
  

Drug: Temozolomide
Given once daily for 49 days followed by 28 days with no drug for a maximum of a year and a half

• Treatment with temozolomide is based upon an 11-week cycle (7 weeks on the drug and 4 weeks off). Patients will receive temozolomide once daily for 49 days, then have 28 days without taking temozolomide.
• Every two to four weeks a physical and neurological examination and blood work will be performed. A magnetic resonance imaging (MRI) scan of the patient's brain will be done approximately every three months (before each cycle of treatment).
• Treatment may continue for a maximum of a year and a half based on 6 eleven-week cycles. The actual duration of therapy will depend upon the response to treatment and the development of side effects or toxicity.

Inclusion Criteria:

• Histological confirmation of a low-grade glioma (astrocytoma, oligodendroglioma, or mixed oligoastrocytoma)
• Measurable disease on MRI
• Patients that have undergone recent resection for newly diagnosed or recurrent or progressive tumor are eligible if they have recovered from the effects of surgery.
• Patients with recurrent disease my have had one prior chemotherapy regimen
• Older than 18 years of age.
• Karnofsky performance status (KPS) performance score of > 70%
• Adequate hematologic, renal and liver functions,
• Life expectancy of greater than 12 weeks.
• Negative pregnancy test.

Exclusion Criteria:

• Prior treatment with temozolomide
• Patients who are not neurologically stable
• Acute infection treated with intravenous antibiotics
• Non-malignant systemic disease
• Frequent vomiting, inability to swallow or a medical condition that could interfere with oral medication.
• Previous or concurrent malignancies at other sites, with the exception of surgically cured carcinoma in-situ of the cervix, and basal or squamous cell carcinoma of the skin.
• HIV positive or AIDS-related illness
• Pregnant or nursing women
• Patients with allergy to decarbazine.