Patients receive oral lomustine on day 1 (course 1 only), oral etoposide on days 1-3, and oral cyclophosphamide and oral procarbazine on days 22-26. Patients may also receive filgrastim (G-CSF) subcutaneously on days 5-21 and 28-42. Treatment repeats every 6 weeks for 2 courses in the absence of disease progression or unacceptable toxicity.