PRIOR CONCURRENT THERAPY: Biologic therapy: 1 prior biologic therapy allowed At least 4 weeks since prior biologic therapy Chemotherapy: 1 prior adjuvant chemotherapy regimen allowed 1 prior chemotherapy regimen for advanced disease allowed At least 4 weeks since prior chemotherapy No concurrent chemotherapy Endocrine therapy: No concurrent steroid therapy No concurrent megestrol acetate Radiotherapy: See Disease Characteristics No concurrent radiotherapy Surgery: See Disease Characteristics At least 2 weeks since prior surgery