PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 4 weeks since prior chemotherapy and recovered At least 8 weeks since prior suramin and/or plasma concentration below 50 microgram/mL Endocrine therapy: See Disease Characteristics Recovered from prior hormonal therapy Concurrent replacement hydrocortisone following prior suramin allowed Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy and recovered Surgery: See Disease Characteristics Recovered from prior surgery