PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior cisplatin, oxaliplatin, nitrosoureas, or mitomycin C 1 or 2 prior chemotherapy regimens allowed (including irinotecan) Endocrine therapy: Not specified Radiotherapy: No prior radiation therapy to whole pelvis, 30% or greater of bone marrow, and site of measurable disease At least 4 weeks since prior radiation therapy and recovered Surgery: Not specified