OUTLINE: All patients receive intravenous pyrazoloacridine (PZA) every 3 weeks in the absence of progressive disease or unacceptable toxicity. Therapy continues in responding patients until 6 months after a complete response or for 1 year, whichever is shorter; stable patients receive a maximum of 4 courses. The dose is increased once for patients who experience minimal toxicity. Patients who fail PZA are encouraged to continue therapy with cyclophosphamide/doxorubicin/fluorouracil (CAF). All patients are followed for survival. Prophylactic granulocyte colony-stimulating factor is not permitted.