OUTLINE: This is an open label, dose escalation study. Patients receive oral temozolomide on days 1-21. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients are treated at escalating doses of temozolomide. The maximum tolerated dose is defined as the dose at which no more than 1 of 6 patients experiences dose limiting toxicity (DLT) during courses 1 or 2, with at least 2 patients experiencing DLT at the next higher dose level.