PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics At least 4 weeks since prior immunotherapy No concurrent immunotherapy or biologic response modifier therapy Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy No concurrent chemotherapy Endocrine therapy: No concurrent corticosteroids Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy No concurrent radiotherapy Surgery: At least 3 weeks since any prior major surgery Other: No organ allograft At least 30 days since any prior investigational agents No concurrent nonsteroidal antiinflammatory agents or aspirin No concurrent alternative therapies (i.e., herbal medicines, high doses of vitamins) No other concurrent investigational agents