PRIOR CONCURRENT THERAPY: Biologic therapy: Colony-stimulating factors allowed for specific indications At least 4 weeks since prior biologic therapy, immunotherapy, or growth factors Chemotherapy: No prior intensive chemotherapy with bone marrow or stem cell support At least 4 weeks since chemotherapy (6 weeks since nitrosoureas, mitomycin, or high-dose carboplatin) Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since radiotherapy Concomitant palliative local radiotherapy allowed for existing lesion Surgery: Recovered from prior surgery Other: No concurrent investigational drug Concurrent prophylactic antiemetics allowed after first therapy course