PRIOR CONCURRENT THERAPY: Biologic therapy: Prior interleukin-2 (IL-2) and/or herceptin allowed No concurrent immunosuppressive drugs or other immunomodulators (other than IL-2) Chemotherapy: At least 6 weeks since nitrosoureas, melphalan, or mitomycin More than 4 weeks since other chemotherapy Endocrine therapy: No concurrent corticosteroids Radiotherapy: More than 4 weeks since prior radiotherapy Surgery: At least 4 weeks since major surgery