PRIOR CONCURRENT THERAPY: Biologic therapy: At least 6 months since prior interleukin-2 therapy At least 6 months since prior interferon alfa therapy At least 1 month since other prior biologic therapy No other concurrent biologic therapy (e.g., filgrastim or sargramostim) Chemotherapy: At least 6 months since prior fluorouracil therapy At least 1 month since prior chemotherapy No other concurrent chemotherapy Endocrine therapy: At least 1 month since prior endocrine therapy No concurrent hormone therapy No concurrent corticosteroids except if inhaled or topical Radiotherapy: At least 1 month since prior radiotherapy (to less than 25% of the bone marrow only, and there must be measurable disease outside of radiation field) No concurrent radiotherapy Surgery: At least 3 weeks since prior surgery Other: No concurrent ongoing therapy with investigational drugs