PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent biologic therapy Chemotherapy: No prior chemotherapy for metastatic disease At least 6 months since prior adjuvant chemotherapy No concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics At least 6 months since prior adjuvant chemoradiation to disease At least 2 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: At least 4 weeks since prior surgery and recovered No concurrent surgery Other: At least 4 weeks since prior investigational drug (including analgesics or antiemetics) No other concurrent anticancer therapy