PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior biologic therapy and recovered No concurrent biologic therapy Chemotherapy: At least 4 weeks since prior chemotherapy and recovered No other concurrent chemotherapy No prior cisplatin or irinotecan Endocrine therapy: At least 4 weeks since prior hormonal therapy and recovered No concurrent hormonal therapy Radiotherapy: At least 4 weeks since prior radiotherapy to less than 25% bone marrow and recovered No concurrent radiotherapy Surgery: At least 4 weeks since prior surgery and recovered No concurrent surgery Other: No other concurrent investigational drugs