PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent biologic therapy with immunomodulatory effects (e.g., interleukin-2, interferon alfa) Chemotherapy: No prior or concurrent local or systemic chemotherapy Endocrine therapy: At least 1 week since prior corticosteroid therapy No concurrent corticosteroid therapy Radiotherapy: See Disease Characteristics Surgery: See Disease Characteristics Other: No concurrent antiproliferatives or immunosuppressants